Add derive macro for Syntax (used to be Language) (#51)

CHANGELOG.md

@@ -3,10 +3,13 @@
 ## `v0.12.0`
 
  * Documentation has been improved in most areas, together with a switch to a more principled module structure that allows explicitly documenting submodules.
+ * The `Language` trait has been deprecated in favour of a new `Syntax` trait. `Syntax` provides the same methods that `Language` did before, but is implemented directly on the syntax kind enum instead of an additional type representing the language.
+   * The supertrait requirements on `PartialOrd`, `Ord`, and `Hash` have been dropped.
+ * TODO: this allows to optionally provide derive. To enable, add feature flag
  * The `interning` module has been rewritten. It now provides fuctions for obtaining a default interner (`new_interner` and `new_threaded_interner`) and provides a small, dependency-free interner implementation.
    * Compatibility with other interners can be enable via feature flags. 
    * **Note** that compatibilty with `lasso` is not enabled by default. Use the `lasso_compat` feature to match the previous default.
- * Introduced `Language::static_text` to optimize tokens that always appear with the same text (estimated 10-15% faster tree building when used, depending on the ratio of static to dynamic tokens).
+ * Introduced `Syntax::static_text` to optimize tokens that always appear with the same text (estimated 10-15% faster tree building when used, depending on the ratio of static to dynamic tokens).
    * Since `cstree`s are lossless, `GreenNodeBuilder::token` must still be passed the source text even for static tokens. 
  * Internal performance improvements for up to 10% faster tree building by avoiding unnecessary duplication of elements.
  * Use `NonNull` for the internal representation of `SyntaxNode`, meaning it now benefits from niche optimizations (`Option<SyntaxNode>` is now the same size as `SyntaxNode` itself: the size of a pointer).
@@ -14,7 +17,7 @@
    * `RawSyntaxKind` has been changed to use a 32-bit index internally, which means existing `Language` implementations and syntax kind `enum`s need to be adjusted to `#[repr(u32)]` and the corresponding conversions.
  * The crate's export module structure has been reorganized to give different groups of definitions their own submodules. A `cstree::prelude` module is available, containing the most commonly needed types that were previously accessible via `use cstree::*`. Otherwise, the module structure is now as follows:
    * `cstree`
-     * `Language`
+     * `Syntax`
      * `RawSyntaxKind`
      * `build`
        * `GreenNodeBuilder`

Cargo.toml

@@ -1,6 +1,12 @@
-[package]
+[workspace]
+members = [
+    "cstree",
+    "cstree-derive",
+    "test_suite",
+]
+
+[workspace.package]
 edition = "2021"
-name = "cstree"
 version = "0.12.0-rc.0" # when updating, also update `#![doc(html_root_url)]`
 authors = [
     "Domenic Quirl <DomenicQuirl@pm.me>",
@@ -10,70 +16,7 @@ description = "Library for generic lossless syntax trees"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/domenicquirl/cstree"
 readme = "README.md"
+rust-version = "1.68"
 
 [profile.release]
 debug = true
-
-[dependencies]
-text-size   = "1.1.0"
-fxhash      = "0.2.1"
-parking_lot = "0.12.1"
-
-# Arc
-triomphe = "0.1.7"
-sptr     = "0.3.2"
-
-# Default Interner
-indexmap = "1.9"
-
-[dependencies.lasso]
-version  = "0.6"
-features = ["inline-more"]
-optional = true
-
-[dependencies.salsa]
-git      = "https://github.com/salsa-rs/salsa/"
-version  = "0.1"
-optional = true
-package  = "salsa-2022"
-
-[dependencies.serde]
-version          = "1.0"
-optional         = true
-default-features = false
-features         = ["derive", "std"]
-
-[dev-dependencies]
-m_lexer         = "0.0.4"
-serde_json      = "1.0"
-serde_test      = "1.0"
-crossbeam-utils = "0.8"
-criterion       = "0.3"
-
-[[bench]]
-name    = "main"
-harness = false
-
-[features]
-default = []
-# Implementations of `serde::{De,}Serialize` for CSTrees.
-serialize = ["serde", "lasso?/serialize"]
-# Interoperability with the `lasso` interning crate.
-# When enabled, `cstree`'s default interners will use `lasso` internally, too.
-lasso_compat = ["lasso"]
-# Additionally provide threadsafe interner types. 
-# Where applicable (and if the corresponding features are selected), provide compatibility 
-# implementations for multi-thread interners from other crates.
-multi_threaded_interning = ["lasso_compat", "lasso/multi-threaded"]
-# Interoperability with the `salsa` framework for incremental computation.
-# Use this feature for "Salsa 2022".
-# WARNING: This feature is considered unstable!
-salsa_2022_compat = ["salsa"]
-
-[[example]]
-name              = "salsa"
-required-features = ["salsa_2022_compat"]
-
-[package.metadata.docs.rs]
-all-features = true
-rustdoc-args = ["--cfg", "doc_cfg"]

README.md

@@ -38,7 +38,7 @@ concrete syntax trees as its output. We'll talk more about parsing below -- firs
 to happen to go from input text to a `cstree` syntax tree:
 
  1. Define an enumeration of the types of tokens (like keywords) and nodes (like "an expression")
- that you want to have in your syntax and implement `Language`
+ that you want to have in your syntax and implement `Syntax`
 
  2. Create a `GreenNodeBuilder` and call `start_node`, `token` and `finish_node` from your parser  
 
@@ -52,12 +52,12 @@ compound expression. They will, however, be allowed to write nested expressions
 ### Defining the language
 First, we need to list the different part of our language's grammar.
 We can do that using an `enum` with a unit variant for any terminal and non-terminal.
-The `enum` needs to be convertible to a `u16`, so we use the `repr` attribute to ensure it uses the correct
+The `enum` needs to be convertible to a `u32`, so we use the `repr` attribute to ensure it uses the correct
 representation.
 
 ```rust
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(u16)]
+#[repr(u32)]
 enum SyntaxKind {
     /* Tokens */
     Int,    // 42
@@ -71,6 +71,15 @@ enum SyntaxKind {
 }
 ```
 
+For convenience when we're working with generic `cstree` types like `SyntaxNode`, we'll also give a
+name to our syntax as a whole and add a type alias for it. 
+That way, we can match against `SyntaxKind`s using the original name, but use the more informative
+`Node<Calculator>` to instantiate `cstree`'s types.
+
+```rust
+type Calculator = SyntaxKind;
+```
+
 Most of these are tokens to lex the input string into, like numbers (`Int`) and operators (`Plus`, `Minus`).
 We only really need one type of node; expressions.
 Our syntax tree's root node will have the special kind `Root`, all other nodes will be
@@ -78,22 +87,16 @@ expressions containing a sequence of arithmetic operations potentially involving
 expression nodes.
 
 To use our `SyntaxKind`s with `cstree`, we need to tell it how to convert it back to just a number (the
-`#[repr(u16)]` that we added) by implementing the `Language` trait. We can also tell `cstree` about tokens that
+`#[repr(u32)]` that we added) by implementing the `Syntax` trait. We can also tell `cstree` about tokens that
 always have the same text through the `static_text` method on the trait. This is useful for the operators and
 parentheses, but not possible for numbers, since an integer token may be produced from the input `3`, but also from
-other numbers like `7` or `12`. We implement `Language` on an empty type, just so we can give it a name.
+other numbers like `7` or `12`. We implement `Syntax` on an empty type, just so we can give it a name.
 
 ```rust
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+impl Syntax for Calculator { 
-pub struct Calculator;
+    fn from_raw(raw: RawSyntaxKind) -> Self {
-
+        // This just needs to be the inverse of `into_raw`, but could also
-impl Language for Calculator {
+        // be an `impl TryFrom<u32> for SyntaxKind` or any other conversion.
-    // The tokens and nodes we just defined
-    type Kind = SyntaxKind;
-
-    fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
-        // This just needs to be the inverse of `kind_to_raw`, but could also
-        // be an `impl TryFrom<u16> for SyntaxKind` or any other conversion.
         match raw.0 {
             0 => SyntaxKind::Int,
             1 => SyntaxKind::Plus,
@@ -106,12 +109,12 @@ impl Language for Calculator {
         }
     }
 
-    fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+    fn ino_raw(self) -> RawSyntaxKind {
-        RawSyntaxKind(kind as u16)
+        RawSyntaxKind(self as u32)
     }
 
-    fn static_text(kind: Self::Kind) -> Option<&'static str> {
+    fn static_text(self) -> Option<&'static str> {
-        match kind {
+        match self {
             SyntaxKind::Plus => Some("+"),
             SyntaxKind::Minus => Some("-"),
             SyntaxKind::LParen => Some("("),
@@ -122,7 +125,14 @@ impl Language for Calculator {
 }
 ```
 
+#### Deriving `Syntax`
+To save yourself the hassle of defining this conversion (and, perhaps more importantly, continually updating it
+while your language's syntax is in flux), `cstree` includes a derive macro for `Syntax` when built with the `derive`
+feature. With the macro, the `Syntax` trait implementation above can be replaced by simply adding
+`#[derive(Syntax)]` to `SyntaxKind`.
+
 ### Parsing into a green tree
+
 With that out of the way, we can start writing the parser for our expressions.
 For the purposes of this introduction to `cstree`, I'll assume that there is a lexer that yields the following
 tokens:

cstree-derive/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name                   = "cstree_derive"
+edition.workspace      = true
+version.workspace      = true
+authors.workspace      = true
+license.workspace      = true
+repository.workspace   = true
+readme.workspace       = true
+rust-version.workspace = true
+
+[lib]
+name       = "cstree_derive"
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.56"
+quote       = "1.0.26"
+syn         = { version = "2.0.14" }

cstree-derive/LICENSE-APACHE

@@ -0,0 +1 @@
+../LICENSE-APACHE

cstree-derive/LICENSE-MIT

@@ -0,0 +1 @@
+../LICENSE-MIT

cstree-derive/README.md

@@ -0,0 +1 @@
+../README.md

cstree-derive/src/errors.rs

@@ -0,0 +1,56 @@
+use std::{cell::RefCell, fmt, thread};
+
+use quote::ToTokens;
+
+/// Context to collect multiple errors and output them all after parsing in order to not abort
+/// immediately on the first error.
+///
+/// Ensures that the errors are handled using [`check`](ErrorContext::check) by otherwise panicking
+/// on `Drop`.
+#[derive(Debug, Default)]
+pub(crate) struct ErrorContext {
+    errors: RefCell<Option<Vec<syn::Error>>>,
+}
+
+impl ErrorContext {
+    /// Create a new context.
+    ///
+    /// This context contains no errors, but will still trigger a panic if it is not `check`ed.
+    pub fn new() -> Self {
+        ErrorContext {
+            errors: RefCell::new(Some(Vec::new())),
+        }
+    }
+
+    /// Add an error to the context that points to `source`.
+    pub fn error_at<S: ToTokens, T: fmt::Display>(&self, source: S, msg: T) {
+        self.errors
+            .borrow_mut()
+            .as_mut()
+            .unwrap()
+            // Transform `ToTokens` here so we don't monomorphize `new_spanned` so much.
+            .push(syn::Error::new_spanned(source.into_token_stream(), msg));
+    }
+
+    /// Add a `syn` parse error directly.
+    pub fn syn_error(&self, err: syn::Error) {
+        self.errors.borrow_mut().as_mut().unwrap().push(err);
+    }
+
+    /// Consume the context, producing a formatted error string if there are errors.
+    pub fn check(self) -> Result<(), Vec<syn::Error>> {
+        let errors = self.errors.borrow_mut().take().unwrap();
+        match errors.len() {
+            0 => Ok(()),
+            _ => Err(errors),
+        }
+    }
+}
+
+impl Drop for ErrorContext {
+    fn drop(&mut self) {
+        if !thread::panicking() && self.errors.borrow().is_some() {
+            panic!("forgot to check for errors");
+        }
+    }
+}

cstree-derive/src/lib.rs

@@ -0,0 +1,74 @@
+use errors::ErrorContext;
+use parsing::SyntaxKindEnum;
+use proc_macro2::TokenStream;
+use quote::{quote, quote_spanned};
+use syn::{parse_macro_input, spanned::Spanned, DeriveInput};
+
+mod errors;
+mod parsing;
+mod symbols;
+
+use symbols::*;
+
+#[proc_macro_derive(Syntax, attributes(static_text))]
+pub fn language(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let ast = parse_macro_input!(input as DeriveInput);
+    expand_syntax(ast).unwrap_or_else(to_compile_errors).into()
+}
+
+fn expand_syntax(ast: DeriveInput) -> Result<TokenStream, Vec<syn::Error>> {
+    let error_handler = ErrorContext::new();
+    let Ok(syntax_kind_enum) = SyntaxKindEnum::parse_from_ast(&error_handler, &ast) else {
+        return Err(error_handler.check().unwrap_err());
+    };
+
+    // Check that the `enum` is `#[repr(u32)]`
+    match &syntax_kind_enum.repr {
+        Some(repr) if repr == U32 => (),
+        Some(_) | None => error_handler.error_at(
+            syntax_kind_enum.source,
+            "syntax kind definitions must be `#[repr(u32)]` to derive `Syntax`",
+        ),
+    }
+
+    error_handler.check()?;
+
+    let name = &syntax_kind_enum.name;
+    let variant_count = syntax_kind_enum.variants.len() as u32;
+    let static_texts = syntax_kind_enum.variants.iter().map(|variant| {
+        let variant_name = &variant.name;
+        let static_text = match variant.static_text.as_deref() {
+            Some(text) => quote!(::core::option::Option::Some(#text)),
+            None => quote!(::core::option::Option::None),
+        };
+        quote_spanned!(variant.source.span()=>
+            #name :: #variant_name => #static_text,
+        )
+    });
+    let trait_impl = quote_spanned! { syntax_kind_enum.source.span()=>
+        #[automatically_derived]
+        impl ::cstree::Syntax for #name {
+            fn from_raw(raw: ::cstree::RawSyntaxKind) -> Self {
+                assert!(raw.0 < #variant_count, "Invalid raw syntax kind: {}", raw.0);
+                // Safety: discriminant is valid by the assert above
+                unsafe { ::std::mem::transmute::<u32, #name>(raw.0) }
+            }
+
+            fn into_raw(self) -> ::cstree::RawSyntaxKind {
+                ::cstree::RawSyntaxKind(self as u32)
+            }
+
+            fn static_text(self) -> ::core::option::Option<&'static str> {
+                match self {
+                    #( #static_texts )*
+                }
+            }
+        }
+    };
+    Ok(trait_impl)
+}
+
+fn to_compile_errors(errors: Vec<syn::Error>) -> proc_macro2::TokenStream {
+    let compile_errors = errors.iter().map(syn::Error::to_compile_error);
+    quote!(#(#compile_errors)*)
+}

cstree-derive/src/parsing.rs

@@ -0,0 +1,131 @@
+mod attributes;
+
+use syn::{punctuated::Punctuated, Token};
+
+use crate::{errors::ErrorContext, symbols::*};
+
+use self::attributes::Attr;
+
+/// Convenience for recording errors inside `ErrorContext` instead of the `Err` variant of the `Result`.
+pub(crate) type Result<T, E = ()> = std::result::Result<T, E>;
+
+pub(crate) struct SyntaxKindEnum<'i> {
+    pub(crate) name:     syn::Ident,
+    pub(crate) repr:     Option<syn::Ident>,
+    pub(crate) variants: Vec<SyntaxKindVariant<'i>>,
+    pub(crate) source:   &'i syn::DeriveInput,
+}
+
+impl<'i> SyntaxKindEnum<'i> {
+    pub(crate) fn parse_from_ast(error_handler: &ErrorContext, item: &'i syn::DeriveInput) -> Result<Self> {
+        let syn::Data::Enum(data) = &item.data else {
+            error_handler.error_at(item, "`Syntax` can only be derived on enums");
+            return Err(());
+        };
+
+        let name = item.ident.clone();
+
+        let mut repr = Attr::none(error_handler, REPR);
+        for repr_attr in item.attrs.iter().filter(|&attr| attr.path().is_ident(&REPR)) {
+            if let syn::Meta::List(nested) = &repr_attr.meta {
+                if let Ok(nested) = nested.parse_args_with(Punctuated::<syn::Meta, Token![,]>::parse_terminated) {
+                    for meta in nested {
+                        if let syn::Meta::Path(path) = meta {
+                            if let Some(ident) = path.get_ident() {
+                                repr.set(repr_attr, ident.clone());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        let variants = data
+            .variants
+            .iter()
+            .map(|variant| SyntaxKindVariant::parse_from_ast(error_handler, variant))
+            .collect();
+
+        Ok(Self {
+            name,
+            repr: repr.get(),
+            variants,
+            source: item,
+        })
+    }
+}
+
+pub(crate) struct SyntaxKindVariant<'i> {
+    pub(crate) name:        syn::Ident,
+    pub(crate) static_text: Option<String>,
+    pub(crate) source:      &'i syn::Variant,
+}
+
+impl<'i> SyntaxKindVariant<'i> {
+    pub(crate) fn parse_from_ast(error_handler: &ErrorContext, variant: &'i syn::Variant) -> Self {
+        let name = variant.ident.clone();
+
+        // Check that `variant` is a unit variant
+        match &variant.fields {
+            syn::Fields::Unit => (),
+            syn::Fields::Named(_) | syn::Fields::Unnamed(_) => {
+                error_handler.error_at(variant, "syntax kinds with fields are not supported");
+            }
+        }
+
+        // Check that discriminants are unaltered
+        if variant.discriminant.is_some() {
+            error_handler.error_at(
+                variant,
+                "syntax kinds are not allowed to have custom discriminant values",
+            );
+        }
+
+        let mut static_text = Attr::none(error_handler, STATIC_TEXT);
+        for text in variant
+            .attrs
+            .iter()
+            .flat_map(|attr| get_static_text(error_handler, attr))
+        {
+            static_text.set(&text, text.value());
+        }
+        Self {
+            name,
+            static_text: static_text.get(),
+            source: variant,
+        }
+    }
+}
+
+fn get_static_text(error_handler: &ErrorContext, attr: &syn::Attribute) -> Option<syn::LitStr> {
+    use syn::Meta::*;
+
+    if attr.path() != STATIC_TEXT {
+        return None;
+    }
+
+    match &attr.meta {
+        List(list) => match list.parse_args() {
+            Ok(lit) => Some(lit),
+            Err(e) => {
+                error_handler.error_at(
+                    list,
+                    "argument to `static_text` must be a string literal: `#[static_text(\"...\")]`",
+                );
+                error_handler.syn_error(e);
+                None
+            }
+        },
+        Path(_) => {
+            error_handler.error_at(attr, "missing text for `static_text`: try `#[static_text(\"...\")]`");
+            None
+        }
+        NameValue(_) => {
+            error_handler.error_at(
+                attr,
+                "`static_text` takes the text as a function argument: `#[static_text(\"...\")]`",
+            );
+            None
+        }
+    }
+}

cstree-derive/src/parsing/attributes.rs

@@ -0,0 +1,59 @@
+#![allow(unused)]
+
+use super::*;
+use proc_macro2::TokenStream;
+use quote::ToTokens;
+
+#[derive(Debug)]
+pub(crate) struct Attr<'i, T> {
+    error_handler: &'i ErrorContext,
+    name: Symbol,
+    tokens: TokenStream,
+    value: Option<T>,
+}
+
+impl<'i, T> Attr<'i, T> {
+    pub(super) fn none(error_handler: &'i ErrorContext, name: Symbol) -> Self {
+        Attr {
+            error_handler,
+            name,
+            tokens: TokenStream::new(),
+            value: None,
+        }
+    }
+
+    pub(super) fn set<S: ToTokens>(&mut self, source: S, value: T) {
+        let tokens = source.into_token_stream();
+
+        if self.value.is_some() {
+            self.error_handler
+                .error_at(tokens, format!("duplicate attribute: `{}`", self.name));
+        } else {
+            self.tokens = tokens;
+            self.value = Some(value);
+        }
+    }
+
+    pub(super) fn set_opt<S: ToTokens>(&mut self, source: S, value: Option<T>) {
+        if let Some(value) = value {
+            self.set(source, value);
+        }
+    }
+
+    pub(super) fn set_if_none(&mut self, value: T) {
+        if self.value.is_none() {
+            self.value = Some(value);
+        }
+    }
+
+    pub(super) fn get(self) -> Option<T> {
+        self.value
+    }
+
+    pub(super) fn get_with_tokens(self) -> Option<(TokenStream, T)> {
+        match self.value {
+            Some(v) => Some((self.tokens, v)),
+            None => None,
+        }
+    }
+}

cstree-derive/src/symbols.rs

@@ -0,0 +1,50 @@
+use std::fmt::{self};
+use syn::{Ident, Path};
+
+#[derive(Copy, Clone)]
+pub struct Symbol(&'static str);
+
+pub const STATIC_TEXT: Symbol = Symbol("static_text");
+pub const REPR: Symbol = Symbol("repr");
+pub const U32: Symbol = Symbol("u32");
+
+impl Symbol {
+    pub const fn new(text: &'static str) -> Self {
+        Self(text)
+    }
+}
+
+impl PartialEq<Symbol> for Ident {
+    fn eq(&self, word: &Symbol) -> bool {
+        self == word.0
+    }
+}
+
+impl<'a> PartialEq<Symbol> for &'a Ident {
+    fn eq(&self, word: &Symbol) -> bool {
+        *self == word.0
+    }
+}
+
+impl PartialEq<Symbol> for Path {
+    fn eq(&self, word: &Symbol) -> bool {
+        self.is_ident(word.0)
+    }
+}
+
+impl<'a> PartialEq<Symbol> for &'a Path {
+    fn eq(&self, word: &Symbol) -> bool {
+        self.is_ident(word.0)
+    }
+}
+
+impl fmt::Display for Symbol {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(self.0)
+    }
+}
+impl fmt::Debug for Symbol {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.debug_tuple("Symbol").field(&self.0).finish()
+    }
+}

cstree/Cargo.toml

@@ -0,0 +1,79 @@
+[package]
+name                   = "cstree"
+edition.workspace      = true
+version.workspace      = true
+authors.workspace      = true
+license.workspace      = true
+repository.workspace   = true
+readme.workspace       = true
+rust-version.workspace = true
+
+[dependencies]
+text-size   = "1.1.0"
+fxhash      = "0.2.1"
+parking_lot = "0.12.1"
+
+# Arc
+triomphe = "0.1.7"
+sptr     = "0.3.2"
+
+# Default Interner
+indexmap = "1.9"
+
+[dependencies.cstree_derive]
+path     = "../cstree-derive"
+optional = true
+
+[dependencies.lasso]
+version  = "0.6"
+features = ["inline-more"]
+optional = true
+
+[dependencies.salsa]
+git      = "https://github.com/salsa-rs/salsa/"
+version  = "0.1"
+optional = true
+package  = "salsa-2022"
+
+[dependencies.serde]
+version          = "1.0"
+optional         = true
+default-features = false
+features         = ["derive", "std"]
+
+[dev-dependencies]
+m_lexer         = "0.0.4"
+serde_json      = "1.0"
+serde_test      = "1.0"
+crossbeam-utils = "0.8"
+criterion       = "0.3"
+
+[[bench]]
+name    = "main"
+harness = false
+
+[features]
+default = []
+# Derive macro for `Syntax`
+derive = ["dep:cstree_derive"]
+# Implementations of `serde::{De,}Serialize` for CSTrees.
+serialize = ["serde", "lasso?/serialize"]
+# Interoperability with the `lasso` interning crate.
+# When enabled, `cstree`'s default interners will use `lasso` internally, too.
+lasso_compat = ["lasso"]
+# Additionally provide threadsafe interner types. 
+# Where applicable (and if the corresponding features are selected), provide compatibility 
+# implementations for multi-thread interners from other crates.
+multi_threaded_interning = ["lasso_compat", "lasso/multi-threaded"]
+# Interoperability with the `salsa` framework for incremental computation.
+# Use this feature for "Salsa 2022".
+# WARNING: This feature is considered unstable!
+salsa_2022_compat = ["salsa"]
+
+[[example]]
+name              = "salsa"
+required-features = ["salsa_2022_compat"]
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "doc_cfg"]

cstree/LICENSE-APACHE

@@ -0,0 +1 @@
+../LICENSE-APACHE

cstree/LICENSE-MIT

@@ -0,0 +1 @@
+../LICENSE-MIT

cstree/README.md

@@ -0,0 +1 @@
+../README.md

cstree/benches/main.rs

@@ -3,9 +3,8 @@ use cstree::{
     build::*,
     green::GreenNode,
     interning::{new_interner, Interner},
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
-use std::{fmt, hash::Hash};
 
 #[derive(Debug)]
 pub enum Element<'s> {
@@ -14,37 +13,14 @@ pub enum Element<'s> {
     Plus,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum TestKind {
     Element { n: u32 },
     Plus,
 }
 
-pub trait Bool: Hash + Ord + fmt::Debug + Copy {
+impl Syntax for TestKind {
-    const VALUE: bool;
+    fn from_raw(raw: RawSyntaxKind) -> Self {
-}
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct TestLang<T: Bool> {
-    _marker: std::marker::PhantomData<T>,
-}
-
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
-pub struct NoStaticText;
-impl Bool for NoStaticText {
-    const VALUE: bool = false;
-}
-
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
-pub struct UseStaticText;
-impl Bool for UseStaticText {
-    const VALUE: bool = true;
-}
-
-impl<T: Bool> Language for TestLang<T> {
-    type Kind = TestKind;
-
-    fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
         if raw.0 == u32::MAX - 1 {
             TestKind::Plus
         } else {
@@ -52,40 +28,37 @@ impl<T: Bool> Language for TestLang<T> {
         }
     }
 
-    fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+    fn into_raw(self) -> RawSyntaxKind {
-        match kind {
+        match self {
             TestKind::Element { n } => RawSyntaxKind(n),
             TestKind::Plus => RawSyntaxKind(u32::MAX - 1),
         }
     }
 
-    fn static_text(kind: Self::Kind) -> Option<&'static str> {
+    fn static_text(self) -> Option<&'static str> {
-        if !<T as Bool>::VALUE {
+        match self {
-            return None;
-        }
-
-        match kind {
             TestKind::Plus => Some("+"),
             TestKind::Element { .. } => None,
         }
     }
 }
 
-pub fn build_tree_with_cache<T: Bool, I>(root: &Element<'_>, cache: &mut NodeCache<'_, I>) -> GreenNode
+pub fn build_tree_with_cache<I>(root: &Element<'_>, cache: &mut NodeCache<'_, I>, use_static_text: bool) -> GreenNode
 where
     I: Interner,
 {
-    let mut builder: GreenNodeBuilder<TestLang<T>, I> = GreenNodeBuilder::with_cache(cache);
+    let mut builder: GreenNodeBuilder<TestKind, I> = GreenNodeBuilder::with_cache(cache);
-    build_recursive(root, &mut builder, 0);
+    build_recursive(root, &mut builder, 0, use_static_text);
     let (node, cache) = builder.finish();
     assert!(cache.is_none());
     node
 }
 
-pub fn build_recursive<T: Bool, I>(
+pub fn build_recursive<I>(
     root: &Element<'_>,
-    builder: &mut GreenNodeBuilder<'_, '_, TestLang<T>, I>,
+    builder: &mut GreenNodeBuilder<'_, '_, TestKind, I>,
     mut from: u32,
+    use_static_text: bool,
 ) -> u32
 where
     I: Interner,
@@ -94,13 +67,16 @@ where
         Element::Node(children) => {
             builder.start_node(TestKind::Element { n: from });
             for child in children {
-                from = build_recursive(child, builder, from + 1);
+                from = build_recursive(child, builder, from + 1, use_static_text);
             }
             builder.finish_node();
         }
         Element::Token(text) => {
             builder.token(TestKind::Element { n: from }, text);
         }
+        Element::Plus if use_static_text => {
+            builder.static_token(TestKind::Plus);
+        }
         Element::Plus => {
             builder.token(TestKind::Plus, "+");
         }
@@ -132,14 +108,14 @@ pub fn create(c: &mut Criterion) {
 
     group.bench_function("with static text", |b| {
         b.iter(|| {
-            let tree = build_tree_with_cache::<UseStaticText, _>(&tree, &mut cache);
+            let tree = build_tree_with_cache(&tree, &mut cache, true);
             black_box(tree);
         })
     });
 
     group.bench_function("without static text", |b| {
         b.iter(|| {
-            let tree = build_tree_with_cache::<NoStaticText, _>(&tree, &mut cache);
+            let tree = build_tree_with_cache(&tree, &mut cache, false);
             black_box(tree);
         })
     });

cstree/examples/math.rs

@@ -13,17 +13,21 @@
 //!     - "+" Token(Add)
 //!     - "4" Token(Number)
 
-use cstree::{build::GreenNodeBuilder, interning::Resolver, util::NodeOrToken};
+use cstree::{build::GreenNodeBuilder, interning::Resolver, util::NodeOrToken, Syntax};
 use std::iter::Peekable;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
 #[repr(u32)]
 enum SyntaxKind {
-    Whitespace = 0,
+    Whitespace,
 
+    #[static_text("+")]
     Add,
+    #[static_text("-")]
     Sub,
+    #[static_text("*")]
     Mul,
+    #[static_text("/")]
     Div,
 
     Number,
@@ -31,6 +35,7 @@ enum SyntaxKind {
     Operation,
     Root,
 }
+type MySyntax = SyntaxKind;
 use SyntaxKind::*;
 
 impl From<SyntaxKind> for cstree::RawSyntaxKind {
@@ -39,40 +44,15 @@ impl From<SyntaxKind> for cstree::RawSyntaxKind {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+type SyntaxNode = cstree::syntax::SyntaxNode<MySyntax>;
-enum Lang {}
-impl cstree::Language for Lang {
-    type Kind = SyntaxKind;
-
-    fn kind_from_raw(raw: cstree::RawSyntaxKind) -> Self::Kind {
-        assert!(raw.0 <= Root as u32);
-        unsafe { std::mem::transmute::<u32, SyntaxKind>(raw.0) }
-    }
-
-    fn kind_to_raw(kind: Self::Kind) -> cstree::RawSyntaxKind {
-        kind.into()
-    }
-
-    fn static_text(kind: Self::Kind) -> Option<&'static str> {
-        match kind {
-            Add => Some("+"),
-            Sub => Some("-"),
-            Mul => Some("*"),
-            Div => Some("/"),
-            _ => None,
-        }
-    }
-}
-
-type SyntaxNode = cstree::syntax::SyntaxNode<Lang>;
 #[allow(unused)]
-type SyntaxToken = cstree::syntax::SyntaxToken<Lang>;
+type SyntaxToken = cstree::syntax::SyntaxToken<MySyntax>;
 #[allow(unused)]
 type SyntaxElement = cstree::util::NodeOrToken<SyntaxNode, SyntaxToken>;
 type SyntaxElementRef<'a> = cstree::util::NodeOrToken<&'a SyntaxNode, &'a SyntaxToken>;
 
 struct Parser<'input, I: Iterator<Item = (SyntaxKind, &'input str)>> {
-    builder: GreenNodeBuilder<'static, 'static, Lang>,
+    builder: GreenNodeBuilder<'static, 'static, MySyntax>,
     iter:    Peekable<I>,
 }
 impl<'input, I: Iterator<Item = (SyntaxKind, &'input str)>> Parser<'input, I> {

cstree/examples/readme.rs

@@ -6,7 +6,7 @@ use cstree::{
     syntax::{ResolvedElementRef, ResolvedNode},
 };
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u32)]
 pub enum SyntaxKind {
     /* Tokens */
@@ -19,16 +19,12 @@ pub enum SyntaxKind {
     Expr,
     Root,
 }
+type Calculator = SyntaxKind;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+impl Syntax for Calculator {
-pub struct Calculator;
+    fn from_raw(raw: RawSyntaxKind) -> Self {
-impl Language for Calculator {
+        // This just needs to be the inverse of `into_raw`, but could also
-    // The tokens and nodes we just defined
+        // be an `impl TryFrom<u32> for SyntaxKind` or any other conversion.
-    type Kind = SyntaxKind;
-
-    fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
-        // This just needs to be the inverse of `kind_to_raw`, but could also
-        // be an `impl TryFrom<u16> for SyntaxKind` or any other conversion.
         match raw.0 {
             0 => SyntaxKind::Int,
             1 => SyntaxKind::Plus,
@@ -41,12 +37,12 @@ impl Language for Calculator {
         }
     }
 
-    fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+    fn into_raw(self) -> RawSyntaxKind {
-        RawSyntaxKind(kind as u32)
+        RawSyntaxKind(self as u32)
     }
 
-    fn static_text(kind: Self::Kind) -> Option<&'static str> {
+    fn static_text(self) -> Option<&'static str> {
-        match kind {
+        match self {
             SyntaxKind::Plus => Some("+"),
             SyntaxKind::Minus => Some("-"),
             SyntaxKind::LParen => Some("("),

cstree/examples/s_expressions.rs

@@ -7,12 +7,23 @@
 //! You may want to follow the conceptual overview of the design alongside this tutorial:
 //! https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/dev/syntax.md
 
-/// Let's start with defining all kinds of tokens and composite nodes.
+use std::collections::VecDeque;
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+
+/// Let's start with defining all kinds of syntactical elements that we want to have in our
+/// language's grammar.  These correspond to tokens and composite nodes in the syntax tree that we
+/// want to parse the S-expressions into.
+use cstree::Syntax;
+
+/// Implementing the `Syntax` trait teaches `cstree` to convert our `SyntaxKind`s to its internal
+/// types, allowing for a nicer `SyntaxNode` API where "kinds" are values from our `enum` instead of
+/// plain `u32` values.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
 #[repr(u32)]
 pub enum SyntaxKind {
-    LParen = 0, // '('
+    #[static_text("(")]
-    RParen,     // ')'
+    LParen, // '('
+    #[static_text(")")]
+    RParen, // ')'
     Word,       // '+', '15'
     Whitespace, // whitespaces is explicit
     Error,      // as well as errors
@@ -22,53 +33,20 @@ pub enum SyntaxKind {
     Atom, // `+`, `15`, wraps a WORD token
     Root, // top-level node: a list of s-expressions
 }
-use std::collections::VecDeque;
 
+/// When matching against the kind of the node, `SyntaxKind::Kind` is a fine name to use.
+/// For specifying generic arguments like `Node<MySyntax>`, we'll use this alias to refer to the
+/// syntax as a whole.
+type SExprSyntax = SyntaxKind;
 use SyntaxKind::*;
 
-/// Some boilerplate is needed, as cstree represents kinds as `struct SyntaxKind(u16)` internally,
+/// `GreenNode` is an immutable tree, which caches identical nodes and tokens, but doesn't contain
-/// in order to not need the user's `enum SyntaxKind` as a type parameter.
-///
-/// First, to easily pass the enum variants into cstree via `.into()`:
-impl From<SyntaxKind> for cstree::RawSyntaxKind {
-    fn from(kind: SyntaxKind) -> Self {
-        Self(kind as u32)
-    }
-}
-
-/// Second, implementing the `Language` trait teaches cstree to convert between these two SyntaxKind
-/// types, allowing for a nicer SyntaxNode API where "kinds" are values from our `enum SyntaxKind`,
-/// instead of plain u16 values.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Lang {}
-impl cstree::Language for Lang {
-    type Kind = SyntaxKind;
-
-    fn kind_from_raw(raw: cstree::RawSyntaxKind) -> Self::Kind {
-        assert!(raw.0 <= Root as u32);
-        unsafe { std::mem::transmute::<u32, SyntaxKind>(raw.0) }
-    }
-
-    fn kind_to_raw(kind: Self::Kind) -> cstree::RawSyntaxKind {
-        kind.into()
-    }
-
-    fn static_text(kind: Self::Kind) -> Option<&'static str> {
-        match kind {
-            LParen => Some("("),
-            RParen => Some(")"),
-            _ => None,
-        }
-    }
-}
-
-/// GreenNode is an immutable tree, which caches identical nodes and tokens, but doesn't contain
 /// offsets and parent pointers.
-/// cstree also deduplicates the actual source string in addition to the tree nodes, so we will need
+/// `cstree` also deduplicates the actual source string in addition to the tree nodes, so we will need
-/// the Resolver to get the real text back from the interned representation.
+/// the `Resolver` to get the real text back from the interned representation.
-use cstree::{green::GreenNode, interning::Resolver, Language};
+use cstree::{green::GreenNode, interning::Resolver};
 
-/// You can construct GreenNodes by hand, but a builder is helpful for top-down parsers: it maintains
+/// You can construct `GreenNode`s by hand, but a builder is helpful for top-down parsers: it maintains
 /// a stack of currently in-progress nodes.
 use cstree::build::GreenNodeBuilder;
 
@@ -89,13 +67,13 @@ fn parse(text: &str) -> Parse<impl Resolver> {
         /// input tokens, including whitespace.
         tokens:  VecDeque<(SyntaxKind, &'input str)>,
         /// the in-progress green tree.
-        builder: GreenNodeBuilder<'static, 'static, Lang>,
+        builder: GreenNodeBuilder<'static, 'static, SExprSyntax>,
         /// the list of syntax errors we've accumulated so far.
         errors:  Vec<String>,
     }
 
     /// The outcome of parsing a single S-expression
-    enum SexpRes {
+    enum SExprResult {
         /// An S-expression (i.e. an atom, or a list) was successfully parsed
         Ok,
         /// Nothing was parsed, as no significant tokens remained
@@ -111,14 +89,14 @@ fn parse(text: &str) -> Parse<impl Resolver> {
             // Parse zero or more S-expressions
             loop {
                 match self.sexp() {
-                    SexpRes::Eof => break,
+                    SExprResult::Eof => break,
-                    SexpRes::RParen => {
+                    SExprResult::RParen => {
                         self.builder.start_node(Error);
                         self.errors.push("unmatched `)`".to_string());
                         self.bump(); // be sure to advance even in case of an error, so as to not get stuck
                         self.builder.finish_node();
                     }
-                    SexpRes::Ok => {}
+                    SExprResult::Ok => {}
                 }
             }
             // Don't forget to eat *trailing* whitespace
@@ -144,28 +122,28 @@ fn parse(text: &str) -> Parse<impl Resolver> {
             self.bump(); // '('
             loop {
                 match self.sexp() {
-                    SexpRes::Eof => {
+                    SExprResult::Eof => {
                         self.errors.push("expected `)`".to_string());
                         break;
                     }
-                    SexpRes::RParen => {
+                    SExprResult::RParen => {
                         self.bump();
                         break;
                     }
-                    SexpRes::Ok => {}
+                    SExprResult::Ok => {}
                 }
             }
             // close the list node
             self.builder.finish_node();
         }
 
-        fn sexp(&mut self) -> SexpRes {
+        fn sexp(&mut self) -> SExprResult {
             // Eat leading whitespace
             self.skip_ws();
             // Either a list, an atom, a closing paren, or an eof.
             let t = match self.current() {
-                None => return SexpRes::Eof,
+                None => return SExprResult::Eof,
-                Some(RParen) => return SexpRes::RParen,
+                Some(RParen) => return SExprResult::RParen,
                 Some(t) => t,
             };
             match t {
@@ -178,7 +156,7 @@ fn parse(text: &str) -> Parse<impl Resolver> {
                 Error => self.bump(),
                 _ => unreachable!(),
             }
-            SexpRes::Ok
+            SExprResult::Ok
         }
 
         /// Advance one token, adding it to the current branch of the tree builder.
@@ -208,13 +186,13 @@ fn parse(text: &str) -> Parse<impl Resolver> {
 }
 
 /// To work with the parse results we need a view into the green tree - the syntax tree.
-/// It is also immutable, like a GreenNode, but it contains parent pointers, offsets, and has
+/// It is also immutable, like a `GreenNode`, but it contains parent pointers, offsets, and has
 /// identity semantics.
-type SyntaxNode = cstree::syntax::SyntaxNode<Lang>;
+type SyntaxNode = cstree::syntax::SyntaxNode<SExprSyntax>;
 #[allow(unused)]
-type SyntaxToken = cstree::syntax::SyntaxToken<Lang>;
+type SyntaxToken = cstree::syntax::SyntaxToken<SExprSyntax>;
 #[allow(unused)]
-type SyntaxElement = cstree::syntax::SyntaxElement<Lang>;
+type SyntaxElement = cstree::syntax::SyntaxElement<SExprSyntax>;
 
 impl<I> Parse<I> {
     fn syntax(&self) -> SyntaxNode {
@@ -292,21 +270,21 @@ mod ast {
     ast_node!(List, List);
 }
 
-// Sexp is slightly different because it can be both an atom and a list, so let's do it by hand.
+// `SExpr` is slightly different because it can be both an atom and a list, so let's do it by hand.
 #[derive(PartialEq, Eq, Hash)]
 #[repr(transparent)]
-struct Sexp(SyntaxNode);
+struct SExpr(SyntaxNode);
 
 enum SexpKind {
     Atom(ast::Atom),
     List(ast::List),
 }
 
-impl Sexp {
+impl SExpr {
     fn cast(node: SyntaxNode) -> Option<Self> {
         use ast::*;
         if Atom::cast(node.clone()).is_some() || List::cast(node.clone()).is_some() {
-            Some(Sexp(node))
+            Some(SExpr(node))
         } else {
             None
         }
@@ -323,8 +301,8 @@ impl Sexp {
 
 // Let's enhance AST nodes with ancillary functions and eval.
 impl ast::Root {
-    fn sexps(&self) -> impl Iterator<Item = Sexp> + '_ {
+    fn sexps(&self) -> impl Iterator<Item = SExpr> + '_ {
-        self.0.children().cloned().filter_map(Sexp::cast)
+        self.0.children().cloned().filter_map(SExpr::cast)
     }
 }
 
@@ -355,7 +333,7 @@ impl ast::Atom {
         use cstree::util::NodeOrToken;
 
         match self.0.green().children().next() {
-            Some(NodeOrToken::Token(token)) => Lang::static_text(Lang::kind_from_raw(token.kind()))
+            Some(NodeOrToken::Token(token)) => SExprSyntax::static_text(SExprSyntax::from_raw(token.kind()))
                 .or_else(|| token.text(resolver))
                 .unwrap(),
             _ => unreachable!(),
@@ -364,8 +342,8 @@ impl ast::Atom {
 }
 
 impl ast::List {
-    fn sexps(&self) -> impl Iterator<Item = Sexp> + '_ {
+    fn sexps(&self) -> impl Iterator<Item = SExpr> + '_ {
-        self.0.children().cloned().filter_map(Sexp::cast)
+        self.0.children().cloned().filter_map(SExpr::cast)
     }
 
     fn eval(&self, resolver: &impl Resolver) -> Option<i64> {
@@ -386,7 +364,7 @@ impl ast::List {
     }
 }
 
-impl Sexp {
+impl SExpr {
     fn eval(&self, resolver: &impl Resolver) -> Option<i64> {
         match self.kind() {
             SexpKind::Atom(atom) => atom.eval(resolver),
@@ -418,10 +396,10 @@ nan
     assert_eq!(res, vec![Some(92), Some(92), None, None, Some(92),])
 }
 
-/// Split the input string into a flat list of tokens (such as L_PAREN, WORD, and WHITESPACE)
+/// Split the input string into a flat list of tokens (such as `LParen`, `Word`, and `Whitespace`)
 fn lex(text: &str) -> VecDeque<(SyntaxKind, &str)> {
     fn tok(t: SyntaxKind) -> m_lexer::TokenKind {
-        m_lexer::TokenKind(cstree::RawSyntaxKind::from(t).0 as u16)
+        m_lexer::TokenKind(t.into_raw().0 as u16)
     }
     fn kind(t: m_lexer::TokenKind) -> SyntaxKind {
         match t.0 {

cstree/examples/salsa.rs

@@ -34,7 +34,7 @@ fn main() {
 
     let interner = db.as_interner();
     let mut shared_interner = &interner;
-    let mut builder: GreenNodeBuilder<TestLang, _> = GreenNodeBuilder::with_interner(&mut shared_interner);
+    let mut builder: GreenNodeBuilder<MySyntax, _> = GreenNodeBuilder::with_interner(&mut shared_interner);
     let (tree, _no_interner_because_it_was_borrowed) = {
         builder.start_node(TestSyntaxKind::Plus);
         builder.token(TestSyntaxKind::Float, "2.05");
@@ -45,6 +45,6 @@ fn main() {
         builder.finish_node();
         builder.finish()
     };
-    let tree: SyntaxNode<TestLang> = SyntaxNode::new_root(tree);
+    let tree: SyntaxNode<MySyntax> = SyntaxNode::new_root(tree);
     assert_eq!(tree.resolve_text(shared_interner), "2.05 + 7.32");
 }

cstree/src/green/builder.rs

@@ -8,7 +8,7 @@ use crate::{
     interning::{new_interner, Interner, TokenInterner, TokenKey},
     util::NodeOrToken,
     utility_types::MaybeOwned,
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 
 use super::{node::GreenNodeHead, token::GreenTokenData};
@@ -35,12 +35,12 @@ impl NodeCache<'static> {
     /// tokens. To re-use an existing interner, see [`with_interner`](NodeCache::with_interner).
     /// # Examples
     /// ```
-    /// # use cstree::testing::{*, Language as _};
+    /// # use cstree::testing::*;
     /// use cstree::build::NodeCache;
     ///
     /// // Build a tree
     /// let mut cache = NodeCache::new();
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::with_cache(&mut cache);
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::with_cache(&mut cache);
     /// # builder.start_node(Root);
     /// # builder.token(Int, "42");
     /// # builder.finish_node();
@@ -48,9 +48,9 @@ impl NodeCache<'static> {
     /// let (tree, _) = builder.finish();
     ///
     /// // Check it out!
-    /// assert_eq!(tree.kind(), MyLanguage::kind_to_raw(Root));
+    /// assert_eq!(tree.kind(), MySyntax::into_raw(Root));
     /// let int = tree.children().next().unwrap();
-    /// assert_eq!(int.kind(), MyLanguage::kind_to_raw(Int));
+    /// assert_eq!(int.kind(), MySyntax::into_raw(Int));
     /// ```
     pub fn new() -> Self {
         Self {
@@ -75,14 +75,14 @@ where
     /// (strings) across tokens.
     /// # Examples
     /// ```
-    /// # use cstree::testing::{*, Language as _};
+    /// # use cstree::testing::*;
     /// # use cstree::interning::*;
     /// use cstree::build::NodeCache;
     ///
     /// // Create the builder from a custom interner
     /// let mut interner = new_interner();
     /// let mut cache = NodeCache::with_interner(&mut interner);
-    /// let mut builder: GreenNodeBuilder<MyLanguage, TokenInterner> =
+    /// let mut builder: GreenNodeBuilder<MySyntax, TokenInterner> =
     ///     GreenNodeBuilder::with_cache(&mut cache);
     ///
     /// // Construct the tree
@@ -93,9 +93,9 @@ where
     /// let (tree, _) = builder.finish();
     ///
     /// // Use the tree
-    /// assert_eq!(tree.kind(), MyLanguage::kind_to_raw(Root));
+    /// assert_eq!(tree.kind(), MySyntax::into_raw(Root));
     /// let int = tree.children().next().unwrap();
-    /// assert_eq!(int.kind(), MyLanguage::kind_to_raw(Int));
+    /// assert_eq!(int.kind(), MySyntax::into_raw(Int));
     /// assert_eq!(int.as_token().unwrap().text(&interner), Some("42"));
     /// ```
     #[inline]
@@ -111,14 +111,14 @@ where
     /// (strings) across tokens.
     /// # Examples
     /// ```
-    /// # use cstree::testing::{*, Language as _};
+    /// # use cstree::testing::*;
     /// # use cstree::interning::*;
     /// use cstree::build::NodeCache;
     ///
     /// // Create the builder from a custom interner
     /// let mut interner = new_interner();
     /// let cache = NodeCache::from_interner(interner);
-    /// let mut builder: GreenNodeBuilder<MyLanguage, TokenInterner> =
+    /// let mut builder: GreenNodeBuilder<MySyntax, TokenInterner> =
     ///     GreenNodeBuilder::from_cache(cache);
     ///
     /// // Construct the tree
@@ -130,9 +130,9 @@ where
     ///
     /// // Use the tree
     /// let interner = cache.unwrap().into_interner().unwrap();
-    /// assert_eq!(tree.kind(), MyLanguage::kind_to_raw(Root));
+    /// assert_eq!(tree.kind(), MySyntax::into_raw(Root));
     /// let int = tree.children().next().unwrap();
-    /// assert_eq!(int.kind(), MyLanguage::kind_to_raw(Int));
+    /// assert_eq!(int.kind(), MySyntax::into_raw(Int));
     /// assert_eq!(int.as_token().unwrap().text(&interner), Some("42"));
     /// ```
     #[inline]
@@ -177,9 +177,9 @@ where
         self.interner.into_owned()
     }
 
-    fn node<L: Language>(&mut self, kind: L::Kind, all_children: &mut Vec<GreenElement>, offset: usize) -> GreenNode {
+    fn node<S: Syntax>(&mut self, kind: S, all_children: &mut Vec<GreenElement>, offset: usize) -> GreenNode {
         // NOTE: this fn must remove all children starting at `first_child` from `all_children` before returning
-        let kind = L::kind_to_raw(kind);
+        let kind = S::into_raw(kind);
         let mut hasher = FxHasher32::default();
         let mut text_len: TextSize = 0.into();
         for child in &all_children[offset..] {
@@ -229,9 +229,9 @@ where
             .clone()
     }
 
-    fn token<L: Language>(&mut self, kind: L::Kind, text: Option<TokenKey>, len: u32) -> GreenToken {
+    fn token<S: Syntax>(&mut self, kind: S, text: Option<TokenKey>, len: u32) -> GreenToken {
         let text_len = TextSize::from(len);
-        let kind = L::kind_to_raw(kind);
+        let kind = S::into_raw(kind);
         let data = GreenTokenData { kind, text, text_len };
         self.tokens
             .entry(data)
@@ -253,29 +253,29 @@ pub struct Checkpoint(usize);
 ///
 /// # Examples
 /// ```
-/// # use cstree::testing::{*, Language as _};
+/// # use cstree::testing::*;
 /// // Build a tree
-/// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+/// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
 /// builder.start_node(Root);
 /// builder.token(Int, "42");
 /// builder.finish_node();
 /// let (tree, cache) = builder.finish();
 ///
 /// // Check it out!
-/// assert_eq!(tree.kind(), MyLanguage::kind_to_raw(Root));
+/// assert_eq!(tree.kind(), MySyntax::into_raw(Root));
 /// let int = tree.children().next().unwrap();
-/// assert_eq!(int.kind(), MyLanguage::kind_to_raw(Int));
+/// assert_eq!(int.kind(), MySyntax::into_raw(Int));
 /// let resolver = cache.unwrap().into_interner().unwrap();
 /// assert_eq!(int.as_token().unwrap().text(&resolver), Some("42"));
 /// ```
 #[derive(Debug)]
-pub struct GreenNodeBuilder<'cache, 'interner, L: Language, I = TokenInterner> {
+pub struct GreenNodeBuilder<'cache, 'interner, S: Syntax, I = TokenInterner> {
     cache:    MaybeOwned<'cache, NodeCache<'interner, I>>,
-    parents:  Vec<(L::Kind, usize)>,
+    parents:  Vec<(S, usize)>,
     children: Vec<GreenElement>,
 }
 
-impl<L: Language> GreenNodeBuilder<'static, 'static, L> {
+impl<S: Syntax> GreenNodeBuilder<'static, 'static, S> {
     /// Creates new builder with an empty [`NodeCache`].
     pub fn new() -> Self {
         Self {
@@ -286,15 +286,15 @@ impl<L: Language> GreenNodeBuilder<'static, 'static, L> {
     }
 }
 
-impl<L: Language> Default for GreenNodeBuilder<'static, 'static, L> {
+impl<S: Syntax> Default for GreenNodeBuilder<'static, 'static, S> {
     fn default() -> Self {
         Self::new()
     }
 }
 
-impl<'cache, 'interner, L, I> GreenNodeBuilder<'cache, 'interner, L, I>
+impl<'cache, 'interner, S, I> GreenNodeBuilder<'cache, 'interner, S, I>
 where
-    L: Language,
+    S: Syntax,
     I: Interner<TokenKey>,
 {
     /// Reusing a [`NodeCache`] between multiple builders saves memory, as it allows to structurally
@@ -312,11 +312,11 @@ where
     /// The `cache` given will be returned on [`finish`](GreenNodeBuilder::finish).
     /// # Examples
     /// ```
-    /// # use cstree::testing::{*, Language as _};
+    /// # use cstree::testing::*;
     /// # use cstree::build::*;
     /// // Construct a builder from our own cache
     /// let cache = NodeCache::new();
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::from_cache(cache);
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::from_cache(cache);
     ///
     /// // Build a tree
     /// # builder.start_node(Root);
@@ -327,9 +327,9 @@ where
     ///
     /// // Use the tree
     /// let interner = cache.unwrap().into_interner().unwrap();
-    /// assert_eq!(tree.kind(), MyLanguage::kind_to_raw(Root));
+    /// assert_eq!(tree.kind(), MySyntax::into_raw(Root));
     /// let int = tree.children().next().unwrap();
-    /// assert_eq!(int.kind(), MyLanguage::kind_to_raw(Int));
+    /// assert_eq!(int.kind(), MySyntax::into_raw(Int));
     /// assert_eq!(int.as_token().unwrap().text(&interner), Some("42"));
     /// ```
     pub fn from_cache(cache: NodeCache<'interner, I>) -> Self {
@@ -377,7 +377,7 @@ where
     /// # use cstree::testing::*;
     /// # use cstree::build::*;
     /// # use cstree::interning::*;
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// let interner = builder.interner_mut();
     /// let key = interner.get_or_intern("foo");
     /// assert_eq!(interner.resolve(key), "foo");
@@ -392,19 +392,19 @@ where
     /// ## Panics
     /// In debug mode, if `kind` has static text, this function will verify that `text` matches that text.
     #[inline]
-    pub fn token(&mut self, kind: L::Kind, text: &str) {
+    pub fn token(&mut self, kind: S, text: &str) {
-        let token = match L::static_text(kind) {
+        let token = match S::static_text(kind) {
             Some(static_text) => {
                 debug_assert_eq!(
                     static_text, text,
                     r#"Received `{kind:?}` token which should have text "{static_text}", but "{text}" was given."#
                 );
-                self.cache.token::<L>(kind, None, static_text.len() as u32)
+                self.cache.token::<S>(kind, None, static_text.len() as u32)
             }
             None => {
                 let len = text.len() as u32;
                 let text = self.cache.intern(text);
-                self.cache.token::<L>(kind, Some(text), len)
+                self.cache.token::<S>(kind, Some(text), len)
             }
         };
         self.children.push(token.into());
@@ -420,15 +420,15 @@ where
     /// ## Panics
     /// If `kind` does not have static text, i.e., `L::static_text(kind)` returns `None`.
     #[inline]
-    pub fn static_token(&mut self, kind: L::Kind) {
+    pub fn static_token(&mut self, kind: S) {
-        let static_text = L::static_text(kind).unwrap_or_else(|| panic!("Missing static text for '{kind:?}'"));
+        let static_text = S::static_text(kind).unwrap_or_else(|| panic!("Missing static text for '{kind:?}'"));
-        let token = self.cache.token::<L>(kind, None, static_text.len() as u32);
+        let token = self.cache.token::<S>(kind, None, static_text.len() as u32);
         self.children.push(token.into());
     }
 
     /// Start new node of the given `kind` and make it current.
     #[inline]
-    pub fn start_node(&mut self, kind: L::Kind) {
+    pub fn start_node(&mut self, kind: S) {
         let len = self.children.len();
         self.parents.push((kind, len));
     }
@@ -438,7 +438,7 @@ where
     pub fn finish_node(&mut self) {
         let (kind, first_child) = self.parents.pop().unwrap();
         // NOTE: we rely on the node cache to remove all children starting at `first_child` from `self.children`
-        let node = self.cache.node::<L>(kind, &mut self.children, first_child);
+        let node = self.cache.node::<S>(kind, &mut self.children, first_child);
         self.children.push(node.into());
     }
 
@@ -450,13 +450,13 @@ where
     /// # Examples
     /// ```
     /// # use cstree::testing::*;
-    /// # use cstree::{build::GreenNodeBuilder, Language};
+    /// # use cstree::build::GreenNodeBuilder;
     /// # struct Parser;
     /// # impl Parser {
     /// #     fn peek(&self) -> Option<TestSyntaxKind> { None }
     /// #     fn parse_expr(&mut self) {}
     /// # }
-    /// # let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// # let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// # let mut parser = Parser;
     /// let checkpoint = builder.checkpoint();
     /// parser.parse_expr();
@@ -475,7 +475,7 @@ where
     /// Wrap the previous branch marked by [`checkpoint`](GreenNodeBuilder::checkpoint) in a new
     /// branch and make it current.
     #[inline]
-    pub fn start_node_at(&mut self, checkpoint: Checkpoint, kind: L::Kind) {
+    pub fn start_node_at(&mut self, checkpoint: Checkpoint, kind: S) {
         let Checkpoint(checkpoint) = checkpoint;
         assert!(
             checkpoint <= self.children.len(),

cstree/src/interning.rs

@@ -5,7 +5,7 @@
 //! [`GreenNodeBuilder::token`], which takes the kind of token and a refernce to the text of the token in the source.
 //!
 //! Of course, there are tokens whose text will always be the same, such as punctuation (like a semicolon), keywords
-//! (like `fn`), or operators (like `<=`). Use [`Language::static_text`] when implementing `Language` to make `cstree`
+//! (like `fn`), or operators (like `<=`). Use [`Syntax::static_text`] when implementing `Syntax` to make `cstree`
 //! aware of such tokens.
 //!
 //! There is, however, another category of tokens whose text will appear repeatedly, but for which we cannot know the
@@ -59,44 +59,45 @@
 //! capabilities with `cstree` as well. Support for this is experimental, and you have to opt in via the
 //! `salsa_2022_compat` feature. For instructions on how to do this, and whether you actually want to, please refer to
 //! [the `salsa_compat` module documentation].
-//!
+#![cfg_attr(
-//! ## Multi-threaded interners
+    feature = "multi_threaded_interning",
-//! If you want to use your interner on more than one thread, the interner needs to support interning new text through
+    doc = r###"
-//! shared access. With the `multi_threaded_interning` feature, you can get such an interner by calling
+## Multi-threaded interners
-//! [`new_threaded_interner`]. The feature also enables support for `ThreadedRodeo`, the multi-threaded interner from
+
-//! `lasso`.
+If you want to use your interner on more than one thread, the interner needs to support interning new text through
-//!
+shared access. With the `multi_threaded_interning` feature, you can get such an interner by calling
-//! **You can pass a reference to that interner to anything that expects an [`Interner`]!**
+[`new_threaded_interner`]. The feature also enables support for `ThreadedRodeo`, the multi-threaded interner from
-//! While the interning methods on [`Interner`] require a `&mut self` to also work for single-threaded interners, both
+`lasso`.
-//! [`Resolver`] and [`Interner`] will be implemented for `&interner` if `interner` is multi-threaded:
+
-//!
+**You can pass a reference to that interner to anything that expects an [`Interner`]!**
-//! ```
+While the interning methods on [`Interner`] require a `&mut self` to also work for single-threaded interners, both
-//! # use cstree::testing::{*, Language as _};
+[`Resolver`] and [`Interner`] will be implemented for `&interner` if `interner` is multi-threaded:
-//! # use cstree::interning::*;
+
-//!
+```
-//! let interner = new_threaded_interner();
+# use cstree::testing::*;
-//! let mut builder: GreenNodeBuilder<MyLanguage, &MultiThreadedTokenInterner> =
+# use cstree::interning::*;
-//!     GreenNodeBuilder::from_interner(&interner);
+let interner = new_threaded_interner();
-//!
+let mut builder: GreenNodeBuilder<MySyntax, &MultiThreadedTokenInterner> =
-//! # builder.start_node(Root);
+    GreenNodeBuilder::from_interner(&interner);
-//! # builder.token(Int, "42");
+# builder.start_node(Root);
-//! # builder.finish_node();
+# builder.token(Int, "42");
-//! parse(&mut builder, "42");
+# builder.finish_node();
-//! let (tree, cache) = builder.finish();
+parse(&mut builder, "42");
-//!
+let (tree, cache) = builder.finish();
-//! // Note that we get a cache and interner back, because we passed an "owned" reference to `from_interner`
+// Note that we get a cache and interner back, because we passed an "owned" reference to `from_interner`
-//! let used_interner = cache.unwrap().into_interner().unwrap();
+let used_interner = cache.unwrap().into_interner().unwrap();
-//! assert_eq!(used_interner as *const _, &interner as *const _);
+assert_eq!(used_interner as *const _, &interner as *const _);
-//!
+let int = tree.children().next().unwrap();
-//! let int = tree.children().next().unwrap();
+assert_eq!(int.as_token().unwrap().text(&interner), Some("42"));
-//! assert_eq!(int.as_token().unwrap().text(&interner), Some("42"));
+```
-//! ```
+
-//!
+Here, we use `from_interner`, but pass it only a shared reference to "own". Take care to denote the type signature
-//! Here, we use `from_interner`, but pass it only a shared reference to "own". Take care to denote the type signature
+of the `GreenNodeBuilder` appropriately.
-//! of the `GreenNodeBuilder` appropriately.
+"###
+)]
 //!
 //! [crate documentation]: crate
-//! [`Language::static_text`]: crate::Language::static_text
+//! [`Syntax::static_text`]: crate::Syntax::static_text
 //! [`GreenNodeBuilder::token`]: crate::build::GreenNodeBuilder::token
 //! [`GreenNodeBuilder::new`]: crate::build::GreenNodeBuilder::new
 //! [`finish`]: crate::build::GreenNodeBuilder::finish

cstree/src/interning/salsa_compat.rs

@@ -55,7 +55,7 @@
 //! let db = Database::default();
 //! let interner = db.as_interner(); // <-- conversion happens here
 //! let mut shared_interner = &interner;
-//! let mut builder: GreenNodeBuilder<TestLang, _> = GreenNodeBuilder::with_interner(&mut shared_interner);
+//! let mut builder: GreenNodeBuilder<MySyntax, _> = GreenNodeBuilder::with_interner(&mut shared_interner);
 //! let (tree, _no_interner_because_it_was_borrowed) = {
 //!     builder.start_node(TestSyntaxKind::Plus);
 //!     builder.token(TestSyntaxKind::Float, "2.05");
@@ -66,7 +66,7 @@
 //!     builder.finish_node();
 //!     builder.finish()
 //! };
-//! let tree: SyntaxNode<TestLang> = SyntaxNode::new_root(tree);
+//! let tree: SyntaxNode<MySyntax> = SyntaxNode::new_root(tree);
 //! assert_eq!(tree.resolve_text(shared_interner), "2.05 + 7.32");
 //! ```
 //!

cstree/src/lib.rs

@@ -40,7 +40,7 @@
 //! to happen to go from input text to a `cstree` syntax tree:
 //!
 //!  1. Define an enumeration of the types of tokens (like keywords) and nodes (like "an expression") that you want to
-//! have in your syntax and implement [`Language`]
+//! have in your syntax and implement [`Syntax`]
 //!
 //!  2. Create a [`GreenNodeBuilder`](build::GreenNodeBuilder) and call
 //! [`start_node`](build::GreenNodeBuilder::start_node), [`token`](build::GreenNodeBuilder::token) and
@@ -61,8 +61,8 @@
 //! The `enum` needs to be convertible to a `u32`, so we use the `repr` attribute to ensure it uses the correct
 //! representation.
 //!
-//! ```rust,ignore
+//! ```rust,no_run
-//! #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+//! #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 //! #[repr(u32)]
 //! enum SyntaxKind {
 //!     /* Tokens */
@@ -77,6 +77,15 @@
 //! }
 //! ```
 //!
+//! For convenience when we're working with generic `cstree` types like `SyntaxNode`, we'll also give a name to our
+//! syntax as a whole and add a type alias for it. That way, we can match against `SyntaxKind`s using the original name,
+//! but use the more informative `Node<Calculator>` to instantiate `cstree`'s types.
+//!
+//! ```rust,no_run
+//! # enum SyntaxKind {}
+//! type Calculator = SyntaxKind;
+//! ```
+//!
 //! Most of these are tokens to lex the input string into, like numbers (`Int`) and operators (`Plus`, `Minus`).
 //! We only really need one type of node; expressions.
 //! Our syntax tree's root node will have the special kind `Root`, all other nodes will be
@@ -84,21 +93,22 @@
 //! expression nodes.
 //!
 //! To use our `SyntaxKind`s with `cstree`, we need to tell it how to convert it back to just a number (the
-//! `#[repr(u16)]` that we added) by implementing the [`Language`] trait. We can also tell `cstree` about tokens that
+//! `#[repr(u32)]` that we added) by implementing the [`Syntax`] trait. We can also tell `cstree` about tokens that
 //! always have the same text through the `static_text` method on the trait. This is useful for the operators and
 //! parentheses, but not possible for numbers, since an integer token may be produced from the input `3`, but also from
-//! other numbers like `7` or `12`. We implement `Language` on an empty type, just so we can give it a name.
+//! other numbers like `7` or `12`.
 //!
-//! ```rust,ignore
+//! ```rust,no_run
-//! #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+//! # #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-//! pub struct Calculator;
+//! # #[repr(u32)]
-//! impl Language for Calculator {
+//! # enum SyntaxKind { Int, Plus, Minus, LParen, RParen, Expr, Root }
-//!     // The tokens and nodes we just defined
+//! # type Calculator = SyntaxKind;
-//!     type Kind = SyntaxKind;
+//! # use cstree::{Syntax, RawSyntaxKind};
 //!
-//!     fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
+//! impl Syntax for Calculator {
-//!         // This just needs to be the inverse of `kind_to_raw`, but could also
+//!     fn from_raw(raw: RawSyntaxKind) -> Self {
-//!         // be an `impl TryFrom<u16> for SyntaxKind` or any other conversion.
+//!         // This just needs to be the inverse of `into_raw`, but could also
+//!         // be an `impl TryFrom<u32> for SyntaxKind` or any other conversion.
 //!         match raw.0 {
 //!             0 => SyntaxKind::Int,
 //!             1 => SyntaxKind::Plus,
@@ -111,12 +121,12 @@
 //!         }
 //!     }
 //!
-//!     fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+//!     fn into_raw(self) -> RawSyntaxKind {
-//!         RawSyntaxKind(kind as u32)
+//!         RawSyntaxKind(self as u32)
 //!     }
 //!
-//!     fn static_text(kind: Self::Kind) -> Option<&'static str> {
+//!     fn static_text(self) -> Option<&'static str> {
-//!         match kind {
+//!         match self {
 //!             SyntaxKind::Plus => Some("+"),
 //!             SyntaxKind::Minus => Some("-"),
 //!             SyntaxKind::LParen => Some("("),
@@ -127,12 +137,21 @@
 //! }
 //! ```
 //!
+//! #### Deriving `Syntax`
+//!
+//! To save yourself the hassle of defining this conversion (and, perhaps more importantly,
+//! continually updating it while your language's syntax is in flux), `cstree` includes a derive
+//! macro for [`Syntax`](macro@crate::Syntax) when built with the `derive` feature. With the macro,
+//! the `Syntax` trait implementation above can be replaced by simply adding `#[derive(Syntax)]` to
+//! `SyntaxKind`.
+//!
 //! ### Parsing into a green tree
+//!
 //! With that out of the way, we can start writing the parser for our expressions.
 //! For the purposes of this introduction to `cstree`, I'll assume that there is a lexer that yields the following
 //! tokens:
 //!
-//! ```rust,ignore
+//! ```rust,no_run
 //! #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 //! pub enum Token<'input> {
 //!     // Note that number strings are not yet parsed into actual numbers,
@@ -150,7 +169,19 @@
 //! A simple lexer that yields such tokens is part of the full `readme` example, but we'll be busy enough with the
 //! combination of `cstree` and the actual parser, which we define like this:
 //!
-//! ```rust,ignore
+//! ```rust,no_run
+//! # use std::iter::Peekable;
+//! # use cstree::build::GreenNodeBuilder;
+//! # struct Lexer<'a> { input: &'a str }
+//! # impl<'a> Lexer<'a> { fn new(input: &'a str) -> Self { Self { input } } }
+//! # struct Token<'a> { input: &'a str }
+//! # impl<'a> Iterator for Lexer<'a> {
+//! #     type Item = Token<'a>;
+//! #     fn next(&mut self) -> Option<Self::Item> { None }
+//! # }
+//! # #[derive(Debug, Clone, Copy, PartialEq, Eq, cstree::Syntax)]
+//! # #[repr(u32)] enum Calculator { A }
+//!
 //! pub struct Parser<'input> {
 //!     // `Peekable` is a standard library iterator adapter that allows
 //!     // looking ahead at the next item without removing it from the iterator yet
@@ -391,7 +422,7 @@ pub mod prelude {
         build::GreenNodeBuilder,
         green::{GreenNode, GreenToken},
         syntax::{SyntaxElement, SyntaxNode, SyntaxToken},
-        Language, RawSyntaxKind,
+        RawSyntaxKind, Syntax,
     };
 }
 
@@ -415,62 +446,39 @@ pub mod sync {
     pub use triomphe::Arc;
 }
 
-/// The `Language` trait is the bridge between the internal `cstree` representation and your
+/// A type that represents what items in your language can be.
+/// Typically, this is an `enum` with variants such as `Identifier`, `Literal`, ...
+///
+/// The `Syntax` trait is the bridge between the internal `cstree` representation and your
 /// language's types.
 /// This is essential for providing a [`SyntaxNode`] API that can be used with your types, as in the
 /// `s_expressions` example:
 ///
 /// ```
-/// #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+/// #[derive(Debug, Clone, Copy, PartialEq, Eq, cstree::Syntax)]
 /// # #[allow(non_camel_case_types)]
 /// #[repr(u32)]
 /// enum SyntaxKind {
-///     Plus,       // `+`
+///     #[static_text("+")]
-///     Minus,      // `-`
+///     Plus, // `+`
+///     #[static_text("-")]
+///     Minus, // `-`
 ///     Integer,    // like `15`
 ///     Expression, // combined expression, like `5 + 4 - 3`
-///     Whitespace, // whitespaces is explicit
+///     Whitespace, // whitespace is explicit
-///     #[doc(hidden)]
-///     __LAST,
-/// }
-/// use SyntaxKind::*;
-///
-/// #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-/// enum Lang {}
-///
-/// impl cstree::Language for Lang {
-///     type Kind = SyntaxKind;
-///
-///     fn kind_from_raw(raw: cstree::RawSyntaxKind) -> Self::Kind {
-///         assert!(raw.0 <= __LAST as u32);
-///         unsafe { std::mem::transmute::<u32, SyntaxKind>(raw.0) }
-///     }
-///
-///     fn kind_to_raw(kind: Self::Kind) -> cstree::RawSyntaxKind {
-///         cstree::RawSyntaxKind(kind as u32)
-///     }
-///
-///     fn static_text(kind: Self::Kind) -> Option<&'static str> {
-///         match kind {
-///             Plus => Some("+"),
-///             Minus => Some("-"),
-///             _ => None,
-///         }
-///     }
 /// }
 /// ```
 ///
+/// `cstree` provides a procedural macro called `cstree_derive` to automatically generate `Syntax` implementations for
+/// syntax kind enums if its `derive` feature is enabled.
+///
 /// [`SyntaxNode`]: crate::syntax::SyntaxNode
-pub trait Language: Sized + Clone + Copy + fmt::Debug + Eq + Ord + std::hash::Hash {
+pub trait Syntax: Sized + Copy + fmt::Debug + Eq {
-    /// A type that represents what items in your Language can be.
-    /// Typically, this is an `enum` with variants such as `Identifier`, `Literal`, ...
-    type Kind: Sized + Clone + Copy + fmt::Debug;
-
     /// Construct a semantic item kind from the compact representation.
-    fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind;
+    fn from_raw(raw: RawSyntaxKind) -> Self;
 
     /// Convert a semantic item kind into a more compact representation.
-    fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind;
+    fn into_raw(self) -> RawSyntaxKind;
 
     /// Fixed text for a particular syntax kind.
     /// Implement for kinds that will only ever represent the same text, such as punctuation (like a
@@ -479,16 +487,25 @@ pub trait Language: Sized + Clone + Copy + fmt::Debug + Eq + Ord + std::hash::Ha
     /// Indicating tokens that have a `static_text` this way allows `cstree` to store them more efficiently, which makes
     /// it faster to add them to a syntax tree and to look up their text. Since there can often be many occurrences
     /// of these tokens inside a file, doing so will improve the performance of using `cstree`.
-    fn static_text(kind: Self::Kind) -> Option<&'static str>;
+    fn static_text(self) -> Option<&'static str>;
 }
 
+#[cfg(feature = "derive")]
+#[allow(unused_imports)]
+#[macro_use]
+extern crate cstree_derive;
+
+#[cfg(feature = "derive")]
+/// Derive macro available if `cstree` is built with `features = ["derive"]`.
+pub use cstree_derive::Syntax;
+
 #[doc(hidden)]
 #[allow(unsafe_code, unused)]
 pub mod testing {
     pub use crate::prelude::*;
-    pub fn parse<L: Language, I>(_b: &mut GreenNodeBuilder<L, I>, _s: &str) {}
+    pub fn parse<S: Syntax, I>(_b: &mut GreenNodeBuilder<S, I>, _s: &str) {}
 
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
     #[repr(u32)]
     #[allow(non_camel_case_types)]
     pub enum TestSyntaxKind {
@@ -501,25 +518,21 @@ pub mod testing {
         Whitespace,
         __LAST,
     }
+    pub type MySyntax = TestSyntaxKind;
     pub use TestSyntaxKind::*;
 
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+    impl Syntax for TestSyntaxKind {
-    pub enum TestLang {}
+        fn from_raw(raw: RawSyntaxKind) -> Self {
-    pub type MyLanguage = TestLang;
-    impl Language for TestLang {
-        type Kind = TestSyntaxKind;
-
-        fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
             assert!(raw.0 <= TestSyntaxKind::__LAST as u32);
-            unsafe { std::mem::transmute::<u32, TestSyntaxKind>(raw.0) }
+            unsafe { std::mem::transmute::<u32, Self>(raw.0) }
         }
 
-        fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+        fn into_raw(self) -> RawSyntaxKind {
-            RawSyntaxKind(kind as u32)
+            RawSyntaxKind(self as u32)
         }
 
-        fn static_text(kind: Self::Kind) -> Option<&'static str> {
+        fn static_text(self) -> Option<&'static str> {
-            match kind {
+            match self {
                 TestSyntaxKind::Plus => Some("+"),
                 _ => None,
             }

cstree/src/serde_impls.rs

@@ -6,7 +6,7 @@ use crate::{
     syntax::{ResolvedNode, SyntaxNode},
     traversal::WalkEvent,
     util::NodeOrToken,
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 use serde::{
     de::{Error, SeqAccess, Visitor},
@@ -40,7 +40,7 @@ macro_rules! data_list {
 /// contains a boolean which indicates if this node has a data. If it has one,
 /// the deserializer should pop the first element from the data list and continue.
 ///
-/// Takes the `Language` (`$l`), `SyntaxNode` (`$node`), `Resolver` (`$resolver`),
+/// Takes the `Syntax` (`$l`), `SyntaxNode` (`$node`), `Resolver` (`$resolver`),
 /// `Serializer` (`$serializer`), and an optional `data_list` which must be a `mut Vec<D>`.
 macro_rules! gen_serialize {
     ($l:ident, $node:expr, $resolver:expr, $ser:ident, $($data_list:ident)?) => {{
@@ -56,9 +56,9 @@ macro_rules! gen_serialize {
                     })
                     .unwrap_or(false);)?
 
-                Some(Event::EnterNode($l::kind_to_raw(node.kind()), has_data))
+                Some(Event::EnterNode($l::into_raw(node.kind()), has_data))
             }
-            WalkEvent::Enter(NodeOrToken::Token(tok)) => Some(Event::Token($l::kind_to_raw(tok.kind()), tok.resolve_text($resolver))),
+            WalkEvent::Enter(NodeOrToken::Token(tok)) => Some(Event::Token($l::into_raw(tok.kind()), tok.resolve_text($resolver))),
 
             WalkEvent::Leave(NodeOrToken::Node(_)) => Some(Event::LeaveNode),
             WalkEvent::Leave(NodeOrToken::Token(_)) => None,
@@ -87,53 +87,53 @@ enum Event<'text> {
 }
 
 /// Make a `SyntaxNode` serializable but without serializing the data.
-pub(crate) struct SerializeWithResolver<'node, 'resolver, L: Language, D: 'static, R: ?Sized> {
+pub(crate) struct SerializeWithResolver<'node, 'resolver, S: Syntax, D: 'static, R: ?Sized> {
-    pub(crate) node:     &'node SyntaxNode<L, D>,
+    pub(crate) node:     &'node SyntaxNode<S, D>,
     pub(crate) resolver: &'resolver R,
 }
 
 /// Make a `SyntaxNode` serializable which will include the data for serialization.
-pub(crate) struct SerializeWithData<'node, 'resolver, L: Language, D: 'static, R: ?Sized> {
+pub(crate) struct SerializeWithData<'node, 'resolver, S: Syntax, D: 'static, R: ?Sized> {
-    pub(crate) node:     &'node SyntaxNode<L, D>,
+    pub(crate) node:     &'node SyntaxNode<S, D>,
     pub(crate) resolver: &'resolver R,
 }
 
-impl<L, D, R> Serialize for SerializeWithData<'_, '_, L, D, R>
+impl<S, D, R> Serialize for SerializeWithData<'_, '_, S, D, R>
 where
-    L: Language,
+    S: Syntax,
     R: Resolver<TokenKey> + ?Sized,
     D: Serialize,
 {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
     where
-        S: serde::Serializer,
+        Ser: serde::Serializer,
     {
         let mut data_list = Vec::new();
-        gen_serialize!(L, self.node, self.resolver, serializer, data_list)
+        gen_serialize!(S, self.node, self.resolver, serializer, data_list)
     }
 }
 
-impl<L, D, R> Serialize for SerializeWithResolver<'_, '_, L, D, R>
+impl<S, D, R> Serialize for SerializeWithResolver<'_, '_, S, D, R>
 where
-    L: Language,
+    S: Syntax,
     R: Resolver<TokenKey> + ?Sized,
 {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
     where
-        S: serde::Serializer,
+        Ser: serde::Serializer,
     {
-        gen_serialize!(L, self.node, self.resolver, serializer,)
+        gen_serialize!(S, self.node, self.resolver, serializer,)
     }
 }
 
-impl<L, D> Serialize for ResolvedNode<L, D>
+impl<S, D> Serialize for ResolvedNode<S, D>
 where
-    L: Language,
+    S: Syntax,
     D: Serialize,
 {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
     where
-        S: serde::Serializer,
+        Ser: serde::Serializer,
     {
         let node = SerializeWithResolver {
             node:     self,
@@ -143,9 +143,9 @@ where
     }
 }
 
-impl<'de, L, D> Deserialize<'de> for ResolvedNode<L, D>
+impl<'de, S, D> Deserialize<'de> for ResolvedNode<S, D>
 where
-    L: Language,
+    S: Syntax,
     D: Deserialize<'de>,
 {
     // Deserialization is done by walking down the deserialized event stream,
@@ -158,20 +158,20 @@ where
     // we walk down the nodes, check if the bool at `data_list[idx]` is true,
     // and if so, pop the first element of the data list and attach the data
     // to the current node.
-    fn deserialize<DE>(deserializer: DE) -> Result<Self, DE::Error>
+    fn deserialize<De>(deserializer: De) -> Result<Self, De::Error>
     where
-        DE: serde::Deserializer<'de>,
+        De: serde::Deserializer<'de>,
     {
-        struct EventVisitor<L: Language, D: 'static> {
+        struct EventVisitor<S: Syntax, D: 'static> {
-            _marker: PhantomData<fn() -> ResolvedNode<L, D>>,
+            _marker: PhantomData<fn() -> ResolvedNode<S, D>>,
         }
 
-        impl<'de, L, D> Visitor<'de> for EventVisitor<L, D>
+        impl<'de, S, D> Visitor<'de> for EventVisitor<S, D>
         where
-            L: Language,
+            S: Syntax,
             D: Deserialize<'de>,
         {
-            type Value = (ResolvedNode<L, D>, VecDeque<bool>);
+            type Value = (ResolvedNode<S, D>, VecDeque<bool>);
 
             fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                 formatter.write_str("a list of tree events")
@@ -181,16 +181,16 @@ where
             where
                 A: SeqAccess<'de>,
             {
-                let mut builder: GreenNodeBuilder<L> = GreenNodeBuilder::new();
+                let mut builder: GreenNodeBuilder<S> = GreenNodeBuilder::new();
                 let mut data_indices = VecDeque::new();
 
                 while let Some(next) = seq.next_element::<Event<'_>>()? {
                     match next {
                         Event::EnterNode(kind, has_data) => {
-                            builder.start_node(L::kind_from_raw(kind));
+                            builder.start_node(S::from_raw(kind));
                             data_indices.push_back(has_data);
                         }
-                        Event::Token(kind, text) => builder.token(L::kind_from_raw(kind), text),
+                        Event::Token(kind, text) => builder.token(S::from_raw(kind), text),
                         Event::LeaveNode => builder.finish_node(),
                     }
                 }
@@ -201,10 +201,10 @@ where
             }
         }
 
-        struct ProcessedEvents<L: Language, D: 'static>(ResolvedNode<L, D>, VecDeque<bool>);
+        struct ProcessedEvents<S: Syntax, D: 'static>(ResolvedNode<S, D>, VecDeque<bool>);
-        impl<'de, L, D> Deserialize<'de> for ProcessedEvents<L, D>
+        impl<'de, S, D> Deserialize<'de> for ProcessedEvents<S, D>
         where
-            L: Language,
+            S: Syntax,
             D: Deserialize<'de>,
         {
             fn deserialize<DE>(deserializer: DE) -> Result<Self, DE::Error>
@@ -217,20 +217,20 @@ where
         }
 
         let (ProcessedEvents(tree, data_indices), mut data) =
-            <(ProcessedEvents<L, D>, VecDeque<D>)>::deserialize(deserializer)?;
+            <(ProcessedEvents<S, D>, VecDeque<D>)>::deserialize(deserializer)?;
 
         tree.descendants().zip(data_indices).try_for_each(|(node, has_data)| {
             if has_data {
                 let data = data
                     .pop_front()
-                    .ok_or_else(|| DE::Error::custom("invalid serialized tree"))?;
+                    .ok_or_else(|| De::Error::custom("invalid serialized tree"))?;
                 node.set_data(data);
             }
-            <Result<(), DE::Error>>::Ok(())
+            <Result<(), De::Error>>::Ok(())
         })?;
 
         if !data.is_empty() {
-            Err(DE::Error::custom(
+            Err(De::Error::custom(
                 "serialized SyntaxNode contained too many data elements",
             ))
         } else {
@@ -240,18 +240,18 @@ where
 }
 
 impl Serialize for RawSyntaxKind {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
     where
-        S: serde::Serializer,
+        Ser: serde::Serializer,
     {
         serializer.serialize_u32(self.0)
     }
 }
 
 impl<'de> Deserialize<'de> for RawSyntaxKind {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    fn deserialize<De>(deserializer: De) -> Result<Self, De::Error>
     where
-        D: serde::Deserializer<'de>,
+        De: serde::Deserializer<'de>,
     {
         Ok(Self(u32::deserialize(deserializer)?))
     }

cstree/src/syntax/element.rs

@@ -7,25 +7,25 @@ use crate::{
     green::GreenElementRef,
     interning::{Resolver, TokenKey},
     util::{NodeOrToken, TokenAtOffset},
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 
 /// An element of the tree, can be either a node or a token.
-pub type SyntaxElement<L, D = ()> = NodeOrToken<SyntaxNode<L, D>, SyntaxToken<L, D>>;
+pub type SyntaxElement<S, D = ()> = NodeOrToken<SyntaxNode<S, D>, SyntaxToken<S, D>>;
 
-impl<L: Language, D> From<SyntaxNode<L, D>> for SyntaxElement<L, D> {
+impl<S: Syntax, D> From<SyntaxNode<S, D>> for SyntaxElement<S, D> {
-    fn from(node: SyntaxNode<L, D>) -> SyntaxElement<L, D> {
+    fn from(node: SyntaxNode<S, D>) -> SyntaxElement<S, D> {
         NodeOrToken::Node(node)
     }
 }
 
-impl<L: Language, D> From<SyntaxToken<L, D>> for SyntaxElement<L, D> {
+impl<S: Syntax, D> From<SyntaxToken<S, D>> for SyntaxElement<S, D> {
-    fn from(token: SyntaxToken<L, D>) -> SyntaxElement<L, D> {
+    fn from(token: SyntaxToken<S, D>) -> SyntaxElement<S, D> {
         NodeOrToken::Token(token)
     }
 }
 
-impl<L: Language, D> SyntaxElement<L, D> {
+impl<S: Syntax, D> SyntaxElement<S, D> {
     /// Returns this element's [`Display`](fmt::Display) representation as a string.
     ///
     /// To avoid allocating for every element, see [`write_display`](type.SyntaxElement.html#method.write_display).
@@ -80,22 +80,22 @@ impl<L: Language, D> SyntaxElement<L, D> {
 }
 
 /// A reference to an element of the tree, can be either a reference to a node or one to a token.
-pub type SyntaxElementRef<'a, L, D = ()> = NodeOrToken<&'a SyntaxNode<L, D>, &'a SyntaxToken<L, D>>;
+pub type SyntaxElementRef<'a, S, D = ()> = NodeOrToken<&'a SyntaxNode<S, D>, &'a SyntaxToken<S, D>>;
 
-impl<'a, L: Language, D> From<&'a SyntaxNode<L, D>> for SyntaxElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a SyntaxNode<S, D>> for SyntaxElementRef<'a, S, D> {
-    fn from(node: &'a SyntaxNode<L, D>) -> Self {
+    fn from(node: &'a SyntaxNode<S, D>) -> Self {
         NodeOrToken::Node(node)
     }
 }
 
-impl<'a, L: Language, D> From<&'a SyntaxToken<L, D>> for SyntaxElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a SyntaxToken<S, D>> for SyntaxElementRef<'a, S, D> {
-    fn from(token: &'a SyntaxToken<L, D>) -> Self {
+    fn from(token: &'a SyntaxToken<S, D>) -> Self {
         NodeOrToken::Token(token)
     }
 }
 
-impl<'a, L: Language, D> From<&'a SyntaxElement<L, D>> for SyntaxElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a SyntaxElement<S, D>> for SyntaxElementRef<'a, S, D> {
-    fn from(element: &'a SyntaxElement<L, D>) -> Self {
+    fn from(element: &'a SyntaxElement<S, D>) -> Self {
         match element {
             NodeOrToken::Node(it) => Self::Node(it),
             NodeOrToken::Token(it) => Self::Token(it),
@@ -103,7 +103,7 @@ impl<'a, L: Language, D> From<&'a SyntaxElement<L, D>> for SyntaxElementRef<'a,
     }
 }
 
-impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> SyntaxElementRef<'a, S, D> {
     /// Returns this element's [`Display`](fmt::Display) representation as a string.
     ///
     /// To avoid allocating for every element, see [`write_display`](type.SyntaxElementRef.html#method.write_display).
@@ -157,14 +157,14 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
     }
 }
 
-impl<L: Language, D> SyntaxElement<L, D> {
+impl<S: Syntax, D> SyntaxElement<S, D> {
     pub(super) fn new(
         element: GreenElementRef<'_>,
-        parent: &SyntaxNode<L, D>,
+        parent: &SyntaxNode<S, D>,
         index: u32,
         offset: TextSize,
         ref_count: *mut AtomicU32,
-    ) -> SyntaxElement<L, D> {
+    ) -> SyntaxElement<S, D> {
         match element {
             NodeOrToken::Node(node) => SyntaxNode::new_child(node, parent, index, offset, ref_count).into(),
             NodeOrToken::Token(_) => SyntaxToken::new(parent, index, offset).into(),
@@ -191,7 +191,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// The kind of this element in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
         match self {
             NodeOrToken::Node(it) => it.kind(),
             NodeOrToken::Token(it) => it.kind(),
@@ -200,7 +200,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// The parent node of this element, except if this element is the root.
     #[inline]
-    pub fn parent(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn parent(&self) -> Option<&SyntaxNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.parent(),
             NodeOrToken::Token(it) => Some(it.parent()),
@@ -209,7 +209,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// Returns an iterator along the chain of parents of this node.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.ancestors(),
             NodeOrToken::Token(it) => it.parent().ancestors(),
@@ -218,7 +218,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// Return the leftmost token in the subtree of this element.
     #[inline]
-    pub fn first_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn first_token(&self) -> Option<&SyntaxToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.first_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -227,7 +227,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// Return the rightmost token in the subtree of this element.
     #[inline]
-    pub fn last_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn last_token(&self) -> Option<&SyntaxToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.last_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -236,7 +236,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// The tree element to the right of this one, i.e. the next child of this element's parent after this element.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.next_sibling_or_token(),
             NodeOrToken::Token(it) => it.next_sibling_or_token(),
@@ -245,7 +245,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
 
     /// The tree element to the left of this one, i.e. the previous child of this element's parent after this element.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.prev_sibling_or_token(),
             NodeOrToken::Token(it) => it.prev_sibling_or_token(),
@@ -253,7 +253,7 @@ impl<L: Language, D> SyntaxElement<L, D> {
     }
 }
 
-impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> SyntaxElementRef<'a, S, D> {
     /// The range this element covers in the source text, in bytes.
     #[inline]
     pub fn text_range(&self) -> TextRange {
@@ -274,7 +274,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// The kind of this element in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
         match self {
             NodeOrToken::Node(it) => it.kind(),
             NodeOrToken::Token(it) => it.kind(),
@@ -283,7 +283,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// The parent node of this element, except if this element is the root.
     #[inline]
-    pub fn parent(&self) -> Option<&'a SyntaxNode<L, D>> {
+    pub fn parent(&self) -> Option<&'a SyntaxNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.parent(),
             NodeOrToken::Token(it) => Some(it.parent()),
@@ -292,7 +292,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// Returns an iterator along the chain of parents of this node.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &'a SyntaxNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &'a SyntaxNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.ancestors(),
             NodeOrToken::Token(it) => it.parent().ancestors(),
@@ -301,7 +301,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// Return the leftmost token in the subtree of this element.
     #[inline]
-    pub fn first_token(&self) -> Option<&'a SyntaxToken<L, D>> {
+    pub fn first_token(&self) -> Option<&'a SyntaxToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.first_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -310,7 +310,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// Return the rightmost token in the subtree of this element.
     #[inline]
-    pub fn last_token(&self) -> Option<&'a SyntaxToken<L, D>> {
+    pub fn last_token(&self) -> Option<&'a SyntaxToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.last_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -319,7 +319,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// The tree element to the right of this one, i.e. the next child of this element's parent after this element.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'a, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'a, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.next_sibling_or_token(),
             NodeOrToken::Token(it) => it.next_sibling_or_token(),
@@ -328,7 +328,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
 
     /// The tree element to the left of this one, i.e. the previous child of this element's parent after this element.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'a, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'a, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.prev_sibling_or_token(),
             NodeOrToken::Token(it) => it.prev_sibling_or_token(),
@@ -336,7 +336,7 @@ impl<'a, L: Language, D> SyntaxElementRef<'a, L, D> {
     }
 
     #[inline]
-    pub(super) fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<SyntaxToken<L, D>> {
+    pub(super) fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<SyntaxToken<S, D>> {
         assert!(self.text_range().start() <= offset && offset <= self.text_range().end());
         match self {
             NodeOrToken::Token(token) => TokenAtOffset::Single((*token).clone()),

cstree/src/syntax/iter.rs

@@ -7,7 +7,7 @@ use text_size::TextSize;
 use crate::{
     green::{GreenElementRef, GreenNodeChildren},
     syntax::{SyntaxElementRef, SyntaxNode},
-    Language,
+    Syntax,
 };
 
 #[derive(Clone, Debug)]
@@ -18,7 +18,7 @@ struct Iter<'n> {
 }
 
 impl<'n> Iter<'n> {
-    fn new<L: Language, D>(parent: &'n SyntaxNode<L, D>) -> Self {
+    fn new<S: Syntax, D>(parent: &'n SyntaxNode<S, D>) -> Self {
         let offset = parent.text_range().start();
         let green: GreenNodeChildren<'_> = parent.green().children();
         Iter {
@@ -67,14 +67,14 @@ impl<'n> FusedIterator for Iter<'n> {}
 
 /// An iterator over the child nodes of a [`SyntaxNode`].
 #[derive(Clone, Debug)]
-pub struct SyntaxNodeChildren<'n, L: Language, D: 'static = ()> {
+pub struct SyntaxNodeChildren<'n, S: Syntax, D: 'static = ()> {
     inner:  Iter<'n>,
-    parent: &'n SyntaxNode<L, D>,
+    parent: &'n SyntaxNode<S, D>,
 }
 
-impl<'n, L: Language, D> SyntaxNodeChildren<'n, L, D> {
+impl<'n, S: Syntax, D> SyntaxNodeChildren<'n, S, D> {
     #[inline]
-    pub(super) fn new(parent: &'n SyntaxNode<L, D>) -> Self {
+    pub(super) fn new(parent: &'n SyntaxNode<S, D>) -> Self {
         Self {
             inner: Iter::new(parent),
             parent,
@@ -82,8 +82,8 @@ impl<'n, L: Language, D> SyntaxNodeChildren<'n, L, D> {
     }
 }
 
-impl<'n, L: Language, D> Iterator for SyntaxNodeChildren<'n, L, D> {
+impl<'n, S: Syntax, D> Iterator for SyntaxNodeChildren<'n, S, D> {
-    type Item = &'n SyntaxNode<L, D>;
+    type Item = &'n SyntaxNode<S, D>;
 
     #[inline(always)]
     fn next(&mut self) -> Option<Self::Item> {
@@ -109,24 +109,24 @@ impl<'n, L: Language, D> Iterator for SyntaxNodeChildren<'n, L, D> {
     }
 }
 
-impl<'n, L: Language, D> ExactSizeIterator for SyntaxNodeChildren<'n, L, D> {
+impl<'n, S: Syntax, D> ExactSizeIterator for SyntaxNodeChildren<'n, S, D> {
     #[inline(always)]
     fn len(&self) -> usize {
         self.inner.len()
     }
 }
-impl<'n, L: Language, D> FusedIterator for SyntaxNodeChildren<'n, L, D> {}
+impl<'n, S: Syntax, D> FusedIterator for SyntaxNodeChildren<'n, S, D> {}
 
 /// An iterator over the children of a [`SyntaxNode`].
 #[derive(Clone, Debug)]
-pub struct SyntaxElementChildren<'n, L: Language, D: 'static = ()> {
+pub struct SyntaxElementChildren<'n, S: Syntax, D: 'static = ()> {
     inner:  Iter<'n>,
-    parent: &'n SyntaxNode<L, D>,
+    parent: &'n SyntaxNode<S, D>,
 }
 
-impl<'n, L: Language, D> SyntaxElementChildren<'n, L, D> {
+impl<'n, S: Syntax, D> SyntaxElementChildren<'n, S, D> {
     #[inline]
-    pub(super) fn new(parent: &'n SyntaxNode<L, D>) -> Self {
+    pub(super) fn new(parent: &'n SyntaxNode<S, D>) -> Self {
         Self {
             inner: Iter::new(parent),
             parent,
@@ -134,8 +134,8 @@ impl<'n, L: Language, D> SyntaxElementChildren<'n, L, D> {
     }
 }
 
-impl<'n, L: Language, D> Iterator for SyntaxElementChildren<'n, L, D> {
+impl<'n, S: Syntax, D> Iterator for SyntaxElementChildren<'n, S, D> {
-    type Item = SyntaxElementRef<'n, L, D>;
+    type Item = SyntaxElementRef<'n, S, D>;
 
     #[inline(always)]
     fn next(&mut self) -> Option<Self::Item> {
@@ -159,10 +159,10 @@ impl<'n, L: Language, D> Iterator for SyntaxElementChildren<'n, L, D> {
     }
 }
 
-impl<'n, L: Language, D> ExactSizeIterator for SyntaxElementChildren<'n, L, D> {
+impl<'n, S: Syntax, D> ExactSizeIterator for SyntaxElementChildren<'n, S, D> {
     #[inline(always)]
     fn len(&self) -> usize {
         self.inner.len()
     }
 }
-impl<'n, L: Language, D> FusedIterator for SyntaxElementChildren<'n, L, D> {}
+impl<'n, S: Syntax, D> FusedIterator for SyntaxElementChildren<'n, S, D> {}

cstree/src/syntax/mod.rs

@@ -22,10 +22,10 @@ pub use text::SyntaxText;
 // A note on `#[inline]` usage in this module:
 // In `rowan`, there are two layers of `SyntaxXY`s: the `cursor` layer and the `api` layer.
 // The `cursor` layer handles all of the actual methods on the tree, while the `api` layer is
-// generic over the `Language` of the tree and otherwise forwards its implementation to the `cursor`
+// generic over the `Syntax` of the tree and otherwise forwards its implementation to the `cursor`
 // layer.
 // Here, we have unified the `cursor` and the `api` layer into the `syntax` layer.
-// This means that all of our types here are generic over a `Language`, including the
+// This means that all of our types here are generic over a `Syntax`, including the
 // implementations which, in `rowan`, are part of the `cursor` layer.
 // Very apparently, this makes the compiler less willing to inline. Almost every "regular use"
 // method in this file has some kind of `#[inline]` annotation to counteract that. This is _NOT_
@@ -43,15 +43,15 @@ mod tests {
     #[cfg_attr(miri, ignore)]
     fn assert_send_sync() {
         fn f<T: Send + Sync>() {}
-        f::<SyntaxNode<TestLang>>();
+        f::<SyntaxNode<TestSyntaxKind>>();
-        f::<SyntaxToken<TestLang>>();
+        f::<SyntaxToken<TestSyntaxKind>>();
-        f::<SyntaxElement<TestLang>>();
+        f::<SyntaxElement<TestSyntaxKind>>();
-        f::<SyntaxElementRef<'static, TestLang>>();
+        f::<SyntaxElementRef<'static, TestSyntaxKind>>();
 
-        f::<ResolvedNode<TestLang>>();
+        f::<ResolvedNode<TestSyntaxKind>>();
-        f::<ResolvedToken<TestLang>>();
+        f::<ResolvedToken<TestSyntaxKind>>();
-        f::<ResolvedElement<TestLang>>();
+        f::<ResolvedElement<TestSyntaxKind>>();
-        f::<ResolvedElementRef<'static, TestLang>>();
+        f::<ResolvedElementRef<'static, TestSyntaxKind>>();
     }
 
     #[test]
@@ -60,10 +60,10 @@ mod tests {
     fn assert_syntax_sizes() {
         use std::mem::size_of;
 
-        assert_eq!(size_of::<SyntaxNode<TestLang>>(),          size_of::<*const u8>());
+        assert_eq!(size_of::<SyntaxNode<TestSyntaxKind>>(),          size_of::<*const u8>());
         // verify niche opt of `NonNull`
-        assert_eq!(size_of::<Option<SyntaxNode<TestLang>>>(),  size_of::<*const u8>()); 
+        assert_eq!(size_of::<Option<SyntaxNode<TestSyntaxKind>>>(),  size_of::<*const u8>()); 
         // parent + child index + text len
-        assert_eq!(size_of::<SyntaxToken<TestLang>>(),         size_of::<SyntaxNode<TestLang>>() + size_of::<u32>() * 2);
+        assert_eq!(size_of::<SyntaxToken<TestSyntaxKind>>(),         size_of::<SyntaxNode<TestSyntaxKind>>() + size_of::<u32>() * 2);
     }
 }

cstree/src/syntax/node.rs

@@ -7,7 +7,7 @@ use crate::{
     text::*,
     traversal::*,
     util::*,
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 use parking_lot::RwLock;
 use std::{
@@ -29,14 +29,14 @@ use triomphe::Arc;
 /// individual nodes is relatively cheap.
 #[derive(Debug)]
 #[repr(transparent)]
-pub struct SyntaxNode<L: Language, D: 'static = ()> {
+pub struct SyntaxNode<S: Syntax, D: 'static = ()> {
-    data: NonNull<NodeData<L, D>>,
+    data: NonNull<NodeData<S, D>>,
 }
 
-unsafe impl<L: Language, D: 'static> Send for SyntaxNode<L, D> {}
+unsafe impl<S: Syntax, D: 'static> Send for SyntaxNode<S, D> {}
-unsafe impl<L: Language, D: 'static> Sync for SyntaxNode<L, D> {}
+unsafe impl<S: Syntax, D: 'static> Sync for SyntaxNode<S, D> {}
 
-impl<L: Language, D> SyntaxNode<L, D> {
+impl<S: Syntax, D> SyntaxNode<S, D> {
     /// Writes this node's [`Debug`](fmt::Debug) representation into the given `target`.
     /// If `recursive` is `true`, prints the entire subtree rooted in this node.
     /// Otherwise, only this node's kind and range are written.
@@ -120,7 +120,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// Turns this node into a [`ResolvedNode`](crate::syntax::ResolvedNode), but only if there is a resolver associated
     /// with this tree.
     #[inline]
-    pub fn try_resolved(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn try_resolved(&self) -> Option<&ResolvedNode<S, D>> {
         // safety: we only coerce if `resolver` exists
         self.resolver().map(|_| unsafe { ResolvedNode::coerce_ref(self) })
     }
@@ -129,12 +129,12 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// # Panics
     /// If there is no resolver associated with this tree.
     #[inline]
-    pub fn resolved(&self) -> &ResolvedNode<L, D> {
+    pub fn resolved(&self) -> &ResolvedNode<S, D> {
         self.try_resolved().expect("tried to resolve a node without resolver")
     }
 }
 
-impl<L: Language, D> Clone for SyntaxNode<L, D> {
+impl<S: Syntax, D> Clone for SyntaxNode<S, D> {
     fn clone(&self) -> Self {
         // safety:: the ref count is only dropped when there are no more external references (see below)
         // since we are currently cloning such a reference, there is still at least one
@@ -144,7 +144,7 @@ impl<L: Language, D> Clone for SyntaxNode<L, D> {
     }
 }
 
-impl<L: Language, D> Drop for SyntaxNode<L, D> {
+impl<S: Syntax, D> Drop for SyntaxNode<S, D> {
     fn drop(&mut self) {
         // safety:: the ref count is only dropped when there are no more external references (see below)
         // and all nodes but the root have been dropped.
@@ -169,9 +169,9 @@ impl<L: Language, D> Drop for SyntaxNode<L, D> {
     }
 }
 
-impl<L: Language, D> SyntaxNode<L, D> {
+impl<S: Syntax, D> SyntaxNode<S, D> {
     #[inline]
-    fn data(&self) -> &NodeData<L, D> {
+    fn data(&self) -> &NodeData<S, D> {
         unsafe { self.data.as_ref() }
     }
 
@@ -183,7 +183,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// The root of the tree this node belongs to.
     ///
     /// If this node is the root, returns `self`.
-    pub fn root(&self) -> &SyntaxNode<L, D> {
+    pub fn root(&self) -> &SyntaxNode<S, D> {
         let mut current = self;
         while let Some(parent) = current.parent() {
             current = parent;
@@ -222,31 +222,31 @@ impl<L: Language, D> SyntaxNode<L, D> {
 }
 
 // Identity semantics for hash & eq
-impl<L: Language, D> PartialEq for SyntaxNode<L, D> {
+impl<S: Syntax, D> PartialEq for SyntaxNode<S, D> {
-    fn eq(&self, other: &SyntaxNode<L, D>) -> bool {
+    fn eq(&self, other: &SyntaxNode<S, D>) -> bool {
         self.data == other.data
     }
 }
 
-impl<L: Language, D> Eq for SyntaxNode<L, D> {}
+impl<S: Syntax, D> Eq for SyntaxNode<S, D> {}
 
-impl<L: Language, D> Hash for SyntaxNode<L, D> {
+impl<S: Syntax, D> Hash for SyntaxNode<S, D> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.data.hash(state);
     }
 }
 
-enum Kind<L: Language, D: 'static> {
+enum Kind<S: Syntax, D: 'static> {
     Root(GreenNode, Option<StdArc<dyn Resolver<TokenKey>>>),
     Child {
-        parent: SyntaxNode<L, D>,
+        parent: SyntaxNode<S, D>,
         index:  u32,
         offset: TextSize,
     },
 }
 
-impl<L: Language, D> Kind<L, D> {
+impl<S: Syntax, D> Kind<S, D> {
-    fn as_child(&self) -> Option<(&SyntaxNode<L, D>, u32, TextSize)> {
+    fn as_child(&self) -> Option<(&SyntaxNode<S, D>, u32, TextSize)> {
         match self {
             Kind::Child { parent, index, offset } => Some((parent, *index, *offset)),
             _ => None,
@@ -254,17 +254,17 @@ impl<L: Language, D> Kind<L, D> {
     }
 }
 
-pub(super) struct NodeData<L: Language, D: 'static> {
+pub(super) struct NodeData<S: Syntax, D: 'static> {
-    kind:        Kind<L, D>,
+    kind:        Kind<S, D>,
     green:       NonNull<GreenNode>,
     ref_count:   *mut AtomicU32,
     data:        RwLock<Option<Arc<D>>>,
-    children:    Vec<UnsafeCell<Option<SyntaxElement<L, D>>>>,
+    children:    Vec<UnsafeCell<Option<SyntaxElement<S, D>>>>,
     child_locks: Vec<RwLock<()>>,
 }
 
-impl<L: Language, D> NodeData<L, D> {
+impl<S: Syntax, D> NodeData<S, D> {
-    fn new(kind: Kind<L, D>, green: NonNull<GreenNode>, ref_count: *mut AtomicU32, n_children: usize) -> NonNull<Self> {
+    fn new(kind: Kind<S, D>, green: NonNull<GreenNode>, ref_count: *mut AtomicU32, n_children: usize) -> NonNull<Self> {
         let mut children = Vec::with_capacity(n_children);
         let mut child_locks = Vec::with_capacity(n_children);
         children.extend((0..n_children).map(|_| Default::default()));
@@ -282,17 +282,17 @@ impl<L: Language, D> NodeData<L, D> {
     }
 }
 
-impl<L: Language, D> SyntaxNode<L, D> {
+impl<S: Syntax, D> SyntaxNode<S, D> {
     /// Build a new syntax tree on top of a green tree.
     ///
     /// # Example
     /// ```
     /// # use cstree::testing::*;
-    /// # let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// # let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// # builder.start_node(Root);
     /// # builder.finish_node();
     /// # let (green_root, _) = builder.finish();
-    /// let root: SyntaxNode<MyLanguage> = SyntaxNode::new_root(green_root);
+    /// let root: SyntaxNode<MySyntax> = SyntaxNode::new_root(green_root);
     /// assert_eq!(root.kind(), Root);
     /// ```
     #[inline]
@@ -300,7 +300,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
         Self::make_new_root(green, None)
     }
 
-    fn new(data: NonNull<NodeData<L, D>>) -> Self {
+    fn new(data: NonNull<NodeData<S, D>>) -> Self {
         Self { data }
     }
 
@@ -334,7 +334,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// # use cstree::testing::*;
     /// use cstree::syntax::ResolvedNode;
     ///
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// builder.start_node(Root);
     /// builder.token(Identifier, "content");
     /// builder.finish_node();
@@ -344,11 +344,11 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// // This created a new interner and cache for us owned by the builder,
     /// // and `finish` always returns these.
     /// let interner = cache.unwrap().into_interner().unwrap();
-    /// let root: ResolvedNode<MyLanguage> = SyntaxNode::new_root_with_resolver(green, interner);
+    /// let root: ResolvedNode<MySyntax> = SyntaxNode::new_root_with_resolver(green, interner);
     /// assert_eq!(root.text(), "content");
     /// ```
     #[inline]
-    pub fn new_root_with_resolver(green: GreenNode, resolver: impl Resolver<TokenKey> + 'static) -> ResolvedNode<L, D> {
+    pub fn new_root_with_resolver(green: GreenNode, resolver: impl Resolver<TokenKey> + 'static) -> ResolvedNode<S, D> {
         let ptr: StdArc<dyn Resolver<TokenKey>> = StdArc::new(resolver);
         ResolvedNode {
             syntax: SyntaxNode::make_new_root(green, Some(ptr)),
@@ -412,7 +412,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     }
 
     #[inline]
-    fn read(&self, index: usize) -> Option<SyntaxElementRef<'_, L, D>> {
+    fn read(&self, index: usize) -> Option<SyntaxElementRef<'_, S, D>> {
         // safety: children are pre-allocated and indices are determined internally
         let _read = unsafe { self.data().child_locks.get_unchecked(index).read() };
         // safety: mutable accesses to the slot only occur below and have to take the lock
@@ -420,7 +420,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
         slot.as_ref().map(|elem| elem.into())
     }
 
-    fn try_write(&self, index: usize, elem: SyntaxElement<L, D>) {
+    fn try_write(&self, index: usize, elem: SyntaxElement<S, D>) {
         // safety: children are pre-allocated and indices are determined internally
         let _write = unsafe { self.data().child_locks.get_unchecked(index).write() };
         // safety: we are the only writer and there are no readers as evidenced by the write lock
@@ -469,7 +469,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
         node: &GreenNode,
         index: usize,
         offset: TextSize,
-    ) -> SyntaxElementRef<'_, L, D> {
+    ) -> SyntaxElementRef<'_, S, D> {
         if let Some(elem) = self.read(index) {
             debug_assert_eq!(elem.text_range().start(), offset);
             return elem;
@@ -487,7 +487,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
         element: GreenElementRef<'_>,
         index: usize,
         offset: TextSize,
-    ) -> SyntaxElementRef<'_, L, D> {
+    ) -> SyntaxElementRef<'_, S, D> {
         if let Some(elem) = self.read(index) {
             debug_assert_eq!(elem.text_range().start(), offset);
             return elem;
@@ -529,8 +529,8 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// The kind of this node in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
-        L::kind_from_raw(self.syntax_kind())
+        S::from_raw(self.syntax_kind())
     }
 
     /// The range this node covers in the source text, in bytes.
@@ -547,7 +547,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// by this node, i.e. the combined text of all token leafs of the subtree originating in this
     /// node.
     #[inline]
-    pub fn resolve_text<'n, 'i, I>(&'n self, resolver: &'i I) -> SyntaxText<'n, 'i, I, L, D>
+    pub fn resolve_text<'n, 'i, I>(&'n self, resolver: &'i I) -> SyntaxText<'n, 'i, I, S, D>
     where
         I: Resolver<TokenKey> + ?Sized,
     {
@@ -562,7 +562,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// The parent node of this node, except if this node is the root.
     #[inline]
-    pub fn parent(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn parent(&self) -> Option<&SyntaxNode<S, D>> {
         match &self.data().kind {
             Kind::Root(_, _) => None,
             Kind::Child { parent, .. } => Some(parent),
@@ -585,7 +585,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// Returns an iterator along the chain of parents of this node.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<S, D>> {
         iter::successors(Some(self), |&node| node.parent())
     }
 
@@ -593,13 +593,13 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`children_with_tokens`](SyntaxNode::children_with_tokens).
     #[inline]
-    pub fn children(&self) -> SyntaxNodeChildren<'_, L, D> {
+    pub fn children(&self) -> SyntaxNodeChildren<'_, S, D> {
         SyntaxNodeChildren::new(self)
     }
 
     /// Returns an iterator over child elements of this node, including tokens.
     #[inline]
-    pub fn children_with_tokens(&self) -> SyntaxElementChildren<'_, L, D> {
+    pub fn children_with_tokens(&self) -> SyntaxElementChildren<'_, S, D> {
         SyntaxElementChildren::new(self)
     }
 
@@ -608,14 +608,14 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// If you want to also consider leafs, see [`first_child_or_token`](SyntaxNode::first_child_or_token).
     #[inline]
     #[allow(clippy::map_clone)]
-    pub fn first_child(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn first_child(&self) -> Option<&SyntaxNode<S, D>> {
         let (node, (index, offset)) = filter_nodes(self.green().children_from(0, self.text_range().start())).next()?;
         self.get_or_add_node(node, index, offset).as_node().map(|node| *node)
     }
 
     /// The first child element of this node, if any, including tokens.
     #[inline]
-    pub fn first_child_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn first_child_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         let (element, (index, offset)) = self.green().children_from(0, self.text_range().start()).next()?;
         Some(self.get_or_add_element(element, index, offset))
     }
@@ -625,7 +625,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// If you want to also consider leafs, see [`last_child_or_token`](SyntaxNode::last_child_or_token).
     #[inline]
     #[allow(clippy::map_clone)]
-    pub fn last_child(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn last_child(&self) -> Option<&SyntaxNode<S, D>> {
         let (node, (index, offset)) = filter_nodes(
             self.green()
                 .children_to(self.green().children().len(), self.text_range().end()),
@@ -636,7 +636,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// The last child element of this node, if any, including tokens.
     #[inline]
-    pub fn last_child_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn last_child_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         let (element, (index, offset)) = self
             .green()
             .children_to(self.green().children().len(), self.text_range().end())
@@ -650,7 +650,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`next_child_or_token_after`](SyntaxNode::next_child_or_token_after).
     #[inline]
-    pub fn next_child_after(&self, n: usize, offset: TextSize) -> Option<&SyntaxNode<L, D>> {
+    pub fn next_child_after(&self, n: usize, offset: TextSize) -> Option<&SyntaxNode<S, D>> {
         let (node, (index, offset)) = filter_nodes(self.green().children_from(n + 1, offset)).next()?;
         self.get_or_add_node(node, index, offset).as_node().copied()
     }
@@ -658,7 +658,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// The first child element of this node starting at the (n + 1)-st, if any.
     /// If this method returns `Some`, the contained node is the (n + 1)-st child of this node.
     #[inline]
-    pub fn next_child_or_token_after(&self, n: usize, offset: TextSize) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn next_child_or_token_after(&self, n: usize, offset: TextSize) -> Option<SyntaxElementRef<'_, S, D>> {
         let (element, (index, offset)) = self.green().children_from(n + 1, offset).next()?;
         Some(self.get_or_add_element(element, index, offset))
     }
@@ -669,7 +669,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`prev_child_or_token_before`](SyntaxNode::prev_child_or_token_before).
     #[inline]
-    pub fn prev_child_before(&self, n: usize, offset: TextSize) -> Option<&SyntaxNode<L, D>> {
+    pub fn prev_child_before(&self, n: usize, offset: TextSize) -> Option<&SyntaxNode<S, D>> {
         let (node, (index, offset)) = filter_nodes(self.green().children_to(n, offset)).next()?;
         self.get_or_add_node(node, index, offset).as_node().copied()
     }
@@ -677,7 +677,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// The last child node of this node up to the nth, if any.
     /// If this method returns `Some`, the contained node is the (n - 1)-st child.
     #[inline]
-    pub fn prev_child_or_token_before(&self, n: usize, offset: TextSize) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn prev_child_or_token_before(&self, n: usize, offset: TextSize) -> Option<SyntaxElementRef<'_, S, D>> {
         let (element, (index, offset)) = self.green().children_to(n, offset).next()?;
         Some(self.get_or_add_element(element, index, offset))
     }
@@ -686,7 +686,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`next_sibling_or_token`](SyntaxNode::next_sibling_or_token).
     #[inline]
-    pub fn next_sibling(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn next_sibling(&self) -> Option<&SyntaxNode<S, D>> {
         let (parent, index, _) = self.data().kind.as_child()?;
 
         let (node, (index, offset)) = filter_nodes(
@@ -700,7 +700,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// The tree element to the right of this one, i.e. the next child of this node's parent after this node.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         let (parent, index, _) = self.data().kind.as_child()?;
 
         let (element, (index, offset)) = parent
@@ -714,7 +714,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`prev_sibling_or_token`](SyntaxNode::prev_sibling_or_token).
     #[inline]
-    pub fn prev_sibling(&self) -> Option<&SyntaxNode<L, D>> {
+    pub fn prev_sibling(&self) -> Option<&SyntaxNode<S, D>> {
         let (parent, index, _) = self.data().kind.as_child()?;
 
         let (node, (index, offset)) =
@@ -724,7 +724,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// The tree element to the left of this one, i.e. the previous child of this node's parent before this node.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         let (parent, index, _) = self.data().kind.as_child()?;
 
         let (element, (index, offset)) = parent
@@ -736,13 +736,13 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// Return the leftmost token in the subtree of this node
     #[inline]
-    pub fn first_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn first_token(&self) -> Option<&SyntaxToken<S, D>> {
         self.first_child_or_token()?.first_token()
     }
 
     /// Return the rightmost token in the subtree of this node
     #[inline]
-    pub fn last_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn last_token(&self) -> Option<&SyntaxToken<S, D>> {
         self.last_child_or_token()?.last_token()
     }
 
@@ -752,7 +752,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`siblings_with_tokens`](SyntaxNode::siblings_with_tokens).
     #[inline]
-    pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = &SyntaxNode<L, D>> {
+    pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = &SyntaxNode<S, D>> {
         iter::successors(Some(self), move |node| match direction {
             Direction::Next => node.next_sibling(),
             Direction::Prev => node.prev_sibling(),
@@ -763,8 +763,8 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// node's parent's children from this node on to the left or the right.
     /// The first item in the iterator will always be this node.
     #[inline]
-    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = SyntaxElementRef<'_, L, D>> {
+    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = SyntaxElementRef<'_, S, D>> {
-        let me: SyntaxElementRef<'_, L, D> = self.into();
+        let me: SyntaxElementRef<'_, S, D> = self.into();
         iter::successors(Some(me), move |el| match direction {
             Direction::Next => el.next_sibling_or_token(),
             Direction::Prev => el.prev_sibling_or_token(),
@@ -775,7 +775,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`descendants_with_tokens`](SyntaxNode::descendants_with_tokens).
     #[inline]
-    pub fn descendants(&self) -> impl Iterator<Item = &SyntaxNode<L, D>> {
+    pub fn descendants(&self) -> impl Iterator<Item = &SyntaxNode<S, D>> {
         self.preorder().filter_map(|event| match event {
             WalkEvent::Enter(node) => Some(node),
             WalkEvent::Leave(_) => None,
@@ -784,7 +784,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// Returns an iterator over all elements in the subtree starting at this node, including this node.
     #[inline]
-    pub fn descendants_with_tokens(&self) -> impl Iterator<Item = SyntaxElementRef<'_, L, D>> {
+    pub fn descendants_with_tokens(&self) -> impl Iterator<Item = SyntaxElementRef<'_, S, D>> {
         self.preorder_with_tokens().filter_map(|event| match event {
             WalkEvent::Enter(it) => Some(it),
             WalkEvent::Leave(_) => None,
@@ -794,7 +794,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// Traverse the subtree rooted at the current node (including the current
     /// node) in preorder, excluding tokens.
     #[inline(always)]
-    pub fn preorder(&self) -> impl Iterator<Item = WalkEvent<&SyntaxNode<L, D>>> {
+    pub fn preorder(&self) -> impl Iterator<Item = WalkEvent<&SyntaxNode<S, D>>> {
         iter::successors(Some(WalkEvent::Enter(self)), move |pos| {
             let next = match pos {
                 WalkEvent::Enter(node) => match node.first_child() {
@@ -818,7 +818,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// Traverse the subtree rooted at the current node (including the current
     /// node) in preorder, including tokens.
     #[inline(always)]
-    pub fn preorder_with_tokens(&self) -> impl Iterator<Item = WalkEvent<SyntaxElementRef<'_, L, D>>> {
+    pub fn preorder_with_tokens(&self) -> impl Iterator<Item = WalkEvent<SyntaxElementRef<'_, S, D>>> {
         let me = self.into();
         iter::successors(Some(WalkEvent::Enter(me)), move |pos| {
             let next = match pos {
@@ -845,7 +845,7 @@ impl<L: Language, D> SyntaxNode<L, D> {
 
     /// Find a token in the subtree corresponding to this node, which covers the offset.
     /// Precondition: offset must be withing node's range.
-    pub fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<SyntaxToken<L, D>> {
+    pub fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<SyntaxToken<S, D>> {
         // TODO: this could be faster if we first drill-down to node, and only
         // then switch to token search. We should also replace explicit
         // recursion with a loop.
@@ -883,8 +883,8 @@ impl<L: Language, D> SyntaxNode<L, D> {
     /// contains the range. If the range is empty and is contained in two leaf
     /// nodes, either one can be returned. Precondition: range must be contained
     /// withing the current node
-    pub fn covering_element(&self, range: TextRange) -> SyntaxElementRef<'_, L, D> {
+    pub fn covering_element(&self, range: TextRange) -> SyntaxElementRef<'_, S, D> {
-        let mut res: SyntaxElementRef<'_, L, D> = self.into();
+        let mut res: SyntaxElementRef<'_, S, D> = self.into();
         loop {
             assert!(
                 res.text_range().contains_range(range),
@@ -909,9 +909,9 @@ impl<L: Language, D> SyntaxNode<L, D> {
 }
 
 #[cfg(feature = "serialize")]
-impl<L, D> SyntaxNode<L, D>
+impl<S, D> SyntaxNode<S, D>
 where
-    L: Language,
+    S: Syntax,
 {
     /// Return an anonymous object that can be used to serialize this node,
     /// including the data and by using an external resolver.

cstree/src/syntax/resolved.rs

@@ -17,7 +17,7 @@ use crate::{
     syntax::*,
     traversal::*,
     util::*,
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 
 /// Syntax tree node that is guaranteed to belong to a tree that contains an associated
@@ -26,24 +26,24 @@ use crate::{
 /// [`SyntaxNode`]
 /// [`SyntaxNode::new_root_with_resolver`]
 #[repr(transparent)]
-pub struct ResolvedNode<L: Language, D: 'static = ()> {
+pub struct ResolvedNode<S: Syntax, D: 'static = ()> {
-    pub(super) syntax: SyntaxNode<L, D>,
+    pub(super) syntax: SyntaxNode<S, D>,
 }
 
-impl<L: Language, D> ResolvedNode<L, D> {
+impl<S: Syntax, D> ResolvedNode<S, D> {
     /// # Safety:
     /// `syntax` must belong to a tree that contains an associated inline resolver.
-    pub(super) unsafe fn coerce_ref(syntax: &SyntaxNode<L, D>) -> &Self {
+    pub(super) unsafe fn coerce_ref(syntax: &SyntaxNode<S, D>) -> &Self {
         &*(syntax as *const _ as *const Self)
     }
 
     /// Returns this node as a [`SyntaxNode`].
-    pub fn syntax(&self) -> &SyntaxNode<L, D> {
+    pub fn syntax(&self) -> &SyntaxNode<S, D> {
         &self.syntax
     }
 }
 
-impl<L: Language, D> Clone for ResolvedNode<L, D> {
+impl<S: Syntax, D> Clone for ResolvedNode<S, D> {
     fn clone(&self) -> Self {
         Self {
             syntax: self.syntax.clone(),
@@ -51,15 +51,15 @@ impl<L: Language, D> Clone for ResolvedNode<L, D> {
     }
 }
 
-impl<L: Language, D> Deref for ResolvedNode<L, D> {
+impl<S: Syntax, D> Deref for ResolvedNode<S, D> {
-    type Target = SyntaxNode<L, D>;
+    type Target = SyntaxNode<S, D>;
 
     fn deref(&self) -> &Self::Target {
         &self.syntax
     }
 }
 
-impl<L: Language, D> DerefMut for ResolvedNode<L, D> {
+impl<S: Syntax, D> DerefMut for ResolvedNode<S, D> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.syntax
     }
@@ -70,24 +70,24 @@ impl<L: Language, D> DerefMut for ResolvedNode<L, D> {
 /// # See also
 /// [`SyntaxToken`]
 #[repr(transparent)]
-pub struct ResolvedToken<L: Language, D: 'static = ()> {
+pub struct ResolvedToken<S: Syntax, D: 'static = ()> {
-    syntax: SyntaxToken<L, D>,
+    syntax: SyntaxToken<S, D>,
 }
 
-impl<L: Language, D> ResolvedToken<L, D> {
+impl<S: Syntax, D> ResolvedToken<S, D> {
     /// # Safety:
     /// `syntax` must belong to a tree that contains an associated inline resolver.
-    pub(super) unsafe fn coerce_ref(syntax: &SyntaxToken<L, D>) -> &Self {
+    pub(super) unsafe fn coerce_ref(syntax: &SyntaxToken<S, D>) -> &Self {
         &*(syntax as *const _ as *const Self)
     }
 
     /// Returns this token as a [`SyntaxToken`].
-    pub fn syntax(&self) -> &SyntaxToken<L, D> {
+    pub fn syntax(&self) -> &SyntaxToken<S, D> {
         &self.syntax
     }
 }
 
-impl<L: Language, D> Clone for ResolvedToken<L, D> {
+impl<S: Syntax, D> Clone for ResolvedToken<S, D> {
     fn clone(&self) -> Self {
         Self {
             syntax: self.syntax.clone(),
@@ -95,15 +95,15 @@ impl<L: Language, D> Clone for ResolvedToken<L, D> {
     }
 }
 
-impl<L: Language, D> Deref for ResolvedToken<L, D> {
+impl<S: Syntax, D> Deref for ResolvedToken<S, D> {
-    type Target = SyntaxToken<L, D>;
+    type Target = SyntaxToken<S, D>;
 
     fn deref(&self) -> &Self::Target {
         &self.syntax
     }
 }
 
-impl<L: Language, D> DerefMut for ResolvedToken<L, D> {
+impl<S: Syntax, D> DerefMut for ResolvedToken<S, D> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.syntax
     }
@@ -113,21 +113,21 @@ impl<L: Language, D> DerefMut for ResolvedToken<L, D> {
 /// [`Resolver`](lasso::Resolver), can be either a node or a token.
 /// # See also
 /// [`SyntaxElement`](crate::syntax::SyntaxElement)
-pub type ResolvedElement<L, D = ()> = NodeOrToken<ResolvedNode<L, D>, ResolvedToken<L, D>>;
+pub type ResolvedElement<S, D = ()> = NodeOrToken<ResolvedNode<S, D>, ResolvedToken<S, D>>;
 
-impl<L: Language, D> From<ResolvedNode<L, D>> for ResolvedElement<L, D> {
+impl<S: Syntax, D> From<ResolvedNode<S, D>> for ResolvedElement<S, D> {
-    fn from(node: ResolvedNode<L, D>) -> ResolvedElement<L, D> {
+    fn from(node: ResolvedNode<S, D>) -> ResolvedElement<S, D> {
         NodeOrToken::Node(node)
     }
 }
 
-impl<L: Language, D> From<ResolvedToken<L, D>> for ResolvedElement<L, D> {
+impl<S: Syntax, D> From<ResolvedToken<S, D>> for ResolvedElement<S, D> {
-    fn from(token: ResolvedToken<L, D>) -> ResolvedElement<L, D> {
+    fn from(token: ResolvedToken<S, D>) -> ResolvedElement<S, D> {
         NodeOrToken::Token(token)
     }
 }
 
-impl<L: Language, D> ResolvedElement<L, D> {
+impl<S: Syntax, D> ResolvedElement<S, D> {
     #[allow(missing_docs)]
     pub fn display(&self, resolver: &impl Resolver<TokenKey>) -> String {
         match self {
@@ -141,12 +141,12 @@ impl<L: Language, D> ResolvedElement<L, D> {
 /// associated [`Resolver`](lasso::Resolver), can be either a reference to a node or one to a token.
 /// # See also
 /// [`SyntaxElementRef`]
-pub type ResolvedElementRef<'a, L, D = ()> = NodeOrToken<&'a ResolvedNode<L, D>, &'a ResolvedToken<L, D>>;
+pub type ResolvedElementRef<'a, S, D = ()> = NodeOrToken<&'a ResolvedNode<S, D>, &'a ResolvedToken<S, D>>;
 
-impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> ResolvedElementRef<'a, S, D> {
     /// # Safety:
     /// `syntax` must belong to a tree that contains an associated inline resolver.
-    pub(super) unsafe fn coerce_ref(syntax: SyntaxElementRef<'a, L, D>) -> Self {
+    pub(super) unsafe fn coerce_ref(syntax: SyntaxElementRef<'a, S, D>) -> Self {
         match syntax {
             NodeOrToken::Node(node) => Self::Node(ResolvedNode::coerce_ref(node)),
             NodeOrToken::Token(token) => Self::Token(ResolvedToken::coerce_ref(token)),
@@ -154,20 +154,20 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
     }
 }
 
-impl<'a, L: Language, D> From<&'a ResolvedNode<L, D>> for ResolvedElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a ResolvedNode<S, D>> for ResolvedElementRef<'a, S, D> {
-    fn from(node: &'a ResolvedNode<L, D>) -> Self {
+    fn from(node: &'a ResolvedNode<S, D>) -> Self {
         NodeOrToken::Node(node)
     }
 }
 
-impl<'a, L: Language, D> From<&'a ResolvedToken<L, D>> for ResolvedElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a ResolvedToken<S, D>> for ResolvedElementRef<'a, S, D> {
-    fn from(token: &'a ResolvedToken<L, D>) -> Self {
+    fn from(token: &'a ResolvedToken<S, D>) -> Self {
         NodeOrToken::Token(token)
     }
 }
 
-impl<'a, L: Language, D> From<&'a ResolvedElement<L, D>> for ResolvedElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> From<&'a ResolvedElement<S, D>> for ResolvedElementRef<'a, S, D> {
-    fn from(element: &'a ResolvedElement<L, D>) -> Self {
+    fn from(element: &'a ResolvedElement<S, D>) -> Self {
         match element {
             NodeOrToken::Node(it) => Self::Node(it),
             NodeOrToken::Token(it) => Self::Token(it),
@@ -175,29 +175,29 @@ impl<'a, L: Language, D> From<&'a ResolvedElement<L, D>> for ResolvedElementRef<
     }
 }
 
-impl<L: Language, D> ResolvedNode<L, D> {
+impl<S: Syntax, D> ResolvedNode<S, D> {
     /// Uses the resolver associated with this tree to return an efficient representation of all
     /// source text covered by this node, i.e. the combined text of all token leafs of the subtree
     /// originating in this node.
     #[inline]
-    pub fn text(&self) -> SyntaxText<'_, '_, dyn Resolver<TokenKey>, L, D> {
+    pub fn text(&self) -> SyntaxText<'_, '_, dyn Resolver<TokenKey>, S, D> {
         SyntaxText::new(self, &**self.resolver())
     }
 }
 
-impl<L: Language, D> fmt::Debug for ResolvedNode<L, D> {
+impl<S: Syntax, D> fmt::Debug for ResolvedNode<S, D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.write_debug(&**self.resolver(), f, f.alternate())
     }
 }
 
-impl<L: Language, D> fmt::Display for ResolvedNode<L, D> {
+impl<S: Syntax, D> fmt::Display for ResolvedNode<S, D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.write_display(&**self.resolver(), f)
     }
 }
 
-impl<L: Language, D> ResolvedToken<L, D> {
+impl<S: Syntax, D> ResolvedToken<S, D> {
     /// Uses the resolver associated with this tree to return the source text of this token.
     #[inline]
     pub fn text(&self) -> &str {
@@ -208,22 +208,22 @@ impl<L: Language, D> ResolvedToken<L, D> {
     }
 }
 
-impl<L: Language, D> fmt::Debug for ResolvedToken<L, D> {
+impl<S: Syntax, D> fmt::Debug for ResolvedToken<S, D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.write_debug(&**self.resolver(), f)
     }
 }
 
-impl<L: Language, D> fmt::Display for ResolvedToken<L, D> {
+impl<S: Syntax, D> fmt::Display for ResolvedToken<S, D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.write_display(&**self.resolver(), f)
     }
 }
 
 #[cfg(feature = "serialize")]
-impl<L, D> ResolvedNode<L, D>
+impl<S, D> ResolvedNode<S, D>
 where
-    L: Language,
+    S: Syntax,
 {
     /// Return an anonymous object that can be used to serialize this node,
     /// including the data for each node.
@@ -267,7 +267,7 @@ macro_rules! forward_node {
     };
 }
 
-impl<L: Language, D> ResolvedNode<L, D> {
+impl<S: Syntax, D> ResolvedNode<S, D> {
     /// Returns the [`Resolver`] associated with this tree.
     pub fn resolver(&self) -> &StdArc<dyn Resolver<TokenKey>> {
         self.syntax.resolver().unwrap()
@@ -283,7 +283,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// This method mostly exists to allow the convenience of being agnostic over [`SyntaxNode`] vs [`ResolvedNode`].
     #[inline]
-    pub fn try_resolved(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn try_resolved(&self) -> Option<&ResolvedNode<S, D>> {
         Some(self)
     }
 
@@ -291,7 +291,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// This method mostly exists to allow the convenience of being agnostic over [`SyntaxNode`] vs [`ResolvedNode`].
     #[inline]
-    pub fn resolved(&self) -> &ResolvedNode<L, D> {
+    pub fn resolved(&self) -> &ResolvedNode<S, D> {
         self
     }
 
@@ -299,7 +299,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If this node is the root, returns `self`.
     #[inline]
-    pub fn root(&self) -> &SyntaxNode<L, D> {
+    pub fn root(&self) -> &SyntaxNode<S, D> {
         unsafe { Self::coerce_ref(self.syntax.root()) }
     }
 
@@ -325,7 +325,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
 
     /// Returns an iterator over child elements of this node, including tokens.
     #[inline]
-    pub fn children_with_tokens(&self) -> impl Iterator<Item = ResolvedElementRef<'_, L, D>> {
+    pub fn children_with_tokens(&self) -> impl Iterator<Item = ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.children_with_tokens())
     }
 
@@ -333,13 +333,13 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`first_child_or_token`](ResolvedNode::first_child_or_token).
     #[inline]
-    pub fn first_child(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn first_child(&self) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.first_child())
     }
 
     /// The first child element of this node, if any, including tokens.
     #[inline]
-    pub fn first_child_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn first_child_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.first_child_or_token())
     }
 
@@ -347,13 +347,13 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`last_child_or_token`](ResolvedNode::last_child_or_token).
     #[inline]
-    pub fn last_child(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn last_child(&self) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.last_child())
     }
 
     /// The last child element of this node, if any, including tokens.
     #[inline]
-    pub fn last_child_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn last_child_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.last_child_or_token())
     }
 
@@ -363,14 +363,14 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`next_child_or_token_after`](ResolvedNode::next_child_or_token_after).
     #[inline]
-    pub fn next_child_after(&self, n: usize, offset: TextSize) -> Option<&ResolvedNode<L, D>> {
+    pub fn next_child_after(&self, n: usize, offset: TextSize) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.next_child_after(n, offset))
     }
 
     /// The first child element of this node starting at the (n + 1)-st, if any.
     /// If this method returns `Some`, the contained node is the (n + 1)-st child of this node.
     #[inline]
-    pub fn next_child_or_token_after(&self, n: usize, offset: TextSize) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn next_child_or_token_after(&self, n: usize, offset: TextSize) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.next_child_or_token_after(n, offset))
     }
 
@@ -381,14 +381,14 @@ impl<L: Language, D> ResolvedNode<L, D> {
     /// If you want to also consider leafs, see
     /// [`prev_child_or_token_before`](ResolvedNode::prev_child_or_token_before).
     #[inline]
-    pub fn prev_child_before(&self, n: usize, offset: TextSize) -> Option<&ResolvedNode<L, D>> {
+    pub fn prev_child_before(&self, n: usize, offset: TextSize) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.prev_child_before(n, offset))
     }
 
     /// The last child node of this node up to the nth, if any.
     /// If this method returns `Some`, the contained node is the (n - 1)-st child.
     #[inline]
-    pub fn prev_child_or_token_before(&self, n: usize, offset: TextSize) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn prev_child_or_token_before(&self, n: usize, offset: TextSize) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.prev_child_or_token_before(n, offset))
     }
 
@@ -396,13 +396,13 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`next_sibling_or_token`](ResolvedNode::next_sibling_or_token).
     #[inline]
-    pub fn next_sibling(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn next_sibling(&self) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.next_sibling())
     }
 
     /// The tree element to the right of this one, i.e. the next child of this node's parent after this node.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.next_sibling_or_token())
     }
 
@@ -410,25 +410,25 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`prev_sibling_or_token`](ResolvedNode::prev_sibling_or_token).
     #[inline]
-    pub fn prev_sibling(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn prev_sibling(&self) -> Option<&ResolvedNode<S, D>> {
         forward!(self.syntax.prev_sibling())
     }
 
     /// The tree element to the left of this one, i.e. the previous child of this node's parent before this node.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.prev_sibling_or_token())
     }
 
     /// Return the leftmost token in the subtree of this node
     #[inline]
-    pub fn first_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn first_token(&self) -> Option<&ResolvedToken<S, D>> {
         forward_token!(self.syntax.first_token())
     }
 
     /// Return the rightmost token in the subtree of this node
     #[inline]
-    pub fn last_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn last_token(&self) -> Option<&ResolvedToken<S, D>> {
         forward_token!(self.syntax.last_token())
     }
 
@@ -438,7 +438,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`siblings_with_tokens`](ResolvedNode::siblings_with_tokens).
     #[inline]
-    pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = &ResolvedNode<L, D>> {
+    pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = &ResolvedNode<S, D>> {
         forward!(self.syntax.siblings(direction))
     }
 
@@ -446,7 +446,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     /// node's parent's children from this node on to the left or the right.
     /// The first item in the iterator will always be this node.
     #[inline]
-    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = ResolvedElementRef<'_, L, D>> {
+    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.siblings_with_tokens(direction))
     }
 
@@ -454,20 +454,20 @@ impl<L: Language, D> ResolvedNode<L, D> {
     ///
     /// If you want to also consider leafs, see [`descendants_with_tokens`](ResolvedNode::descendants_with_tokens).
     #[inline]
-    pub fn descendants(&self) -> impl Iterator<Item = &ResolvedNode<L, D>> {
+    pub fn descendants(&self) -> impl Iterator<Item = &ResolvedNode<S, D>> {
         forward!(self.syntax.descendants())
     }
 
     /// Returns an iterator over all elements in the subtree starting at this node, including this node.
     #[inline]
-    pub fn descendants_with_tokens(&self) -> impl Iterator<Item = ResolvedElementRef<'_, L, D>> {
+    pub fn descendants_with_tokens(&self) -> impl Iterator<Item = ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.descendants_with_tokens())
     }
 
     /// Traverse the subtree rooted at the current node (including the current
     /// node) in preorder, excluding tokens.
     #[inline(always)]
-    pub fn preorder(&self) -> impl Iterator<Item = WalkEvent<&ResolvedNode<L, D>>> {
+    pub fn preorder(&self) -> impl Iterator<Item = WalkEvent<&ResolvedNode<S, D>>> {
         self.syntax
             .preorder()
             .map(|event| event.map(|node| unsafe { Self::coerce_ref(node) }))
@@ -476,7 +476,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
     /// Traverse the subtree rooted at the current node (including the current
     /// node) in preorder, including tokens.
     #[inline(always)]
-    pub fn preorder_with_tokens(&self) -> impl Iterator<Item = WalkEvent<ResolvedElementRef<'_, L, D>>> {
+    pub fn preorder_with_tokens(&self) -> impl Iterator<Item = WalkEvent<ResolvedElementRef<'_, S, D>>> {
         self.syntax
             .preorder_with_tokens()
             .map(|event| event.map(|elem| unsafe { ResolvedElementRef::coerce_ref(elem) }))
@@ -484,7 +484,7 @@ impl<L: Language, D> ResolvedNode<L, D> {
 
     /// Find a token in the subtree corresponding to this node, which covers the offset.
     /// Precondition: offset must be withing node's range.
-    pub fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<ResolvedToken<L, D>> {
+    pub fn token_at_offset(&self, offset: TextSize) -> TokenAtOffset<ResolvedToken<S, D>> {
         self.syntax
             .token_at_offset(offset)
             .map(|token| ResolvedToken { syntax: token })
@@ -494,12 +494,12 @@ impl<L: Language, D> ResolvedNode<L, D> {
     /// contains the range. If the range is empty and is contained in two leaf
     /// nodes, either one can be returned. Precondition: range must be contained
     /// withing the current node
-    pub fn covering_element(&self, range: TextRange) -> ResolvedElementRef<'_, L, D> {
+    pub fn covering_element(&self, range: TextRange) -> ResolvedElementRef<'_, S, D> {
         unsafe { ResolvedElementRef::coerce_ref(self.syntax.covering_element(range)) }
     }
 }
 
-impl<L: Language, D> ResolvedToken<L, D> {
+impl<S: Syntax, D> ResolvedToken<S, D> {
     /// Returns the [`Resolver`] associated with this tree.
     pub fn resolver(&self) -> &StdArc<dyn Resolver<TokenKey>> {
         self.syntax.resolver().unwrap()
@@ -509,7 +509,7 @@ impl<L: Language, D> ResolvedToken<L, D> {
     ///
     /// This method mostly exists to allow the convenience of being agnostic over [`SyntaxToken`] vs [`ResolvedToken`].
     #[inline]
-    pub fn try_resolved(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn try_resolved(&self) -> Option<&ResolvedToken<S, D>> {
         Some(self)
     }
 
@@ -517,31 +517,31 @@ impl<L: Language, D> ResolvedToken<L, D> {
     ///
     /// This method mostly exists to allow the convenience of being agnostic over [`SyntaxToken`] vs [`ResolvedToken`].
     #[inline]
-    pub fn resolved(&self) -> &ResolvedToken<L, D> {
+    pub fn resolved(&self) -> &ResolvedToken<S, D> {
         self
     }
 
     /// The parent node of this token.
     #[inline]
-    pub fn parent(&self) -> &ResolvedNode<L, D> {
+    pub fn parent(&self) -> &ResolvedNode<S, D> {
         unsafe { ResolvedNode::coerce_ref(self.syntax.parent()) }
     }
 
     /// Returns an iterator along the chain of parents of this token.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &ResolvedNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &ResolvedNode<S, D>> {
         forward_node!(self.syntax.ancestors())
     }
 
     /// The tree element to the right of this one, i.e. the next child of this token's parent after this token.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.next_sibling_or_token())
     }
 
     /// The tree element to the left of this one, i.e. the previous child of this token's parent after this token.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.prev_sibling_or_token())
     }
 
@@ -549,24 +549,24 @@ impl<L: Language, D> ResolvedToken<L, D> {
     /// token's parent's children from this token on to the left or the right.
     /// The first item in the iterator will always be this token.
     #[inline]
-    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = ResolvedElementRef<'_, L, D>> {
+    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = ResolvedElementRef<'_, S, D>> {
         forward_as_elem!(self.syntax.siblings_with_tokens(direction))
     }
 
     /// Returns the next token in the tree.
     /// This is not necessary a direct sibling of this token, but will always be further right in the tree.
-    pub fn next_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn next_token(&self) -> Option<&ResolvedToken<S, D>> {
         forward!(self.syntax.next_token())
     }
 
     /// Returns the previous token in the tree.
     /// This is not necessary a direct sibling of this token, but will always be further left in the tree.
-    pub fn prev_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn prev_token(&self) -> Option<&ResolvedToken<S, D>> {
         forward!(self.syntax.prev_token())
     }
 }
 
-impl<L: Language, D> ResolvedElement<L, D> {
+impl<S: Syntax, D> ResolvedElement<S, D> {
     /// The range this element covers in the source text, in bytes.
     #[inline]
     pub fn text_range(&self) -> TextRange {
@@ -587,7 +587,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// The kind of this element in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
         match self {
             NodeOrToken::Node(it) => it.kind(),
             NodeOrToken::Token(it) => it.kind(),
@@ -596,7 +596,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// The parent node of this element, except if this element is the root.
     #[inline]
-    pub fn parent(&self) -> Option<&ResolvedNode<L, D>> {
+    pub fn parent(&self) -> Option<&ResolvedNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.parent(),
             NodeOrToken::Token(it) => Some(it.parent()),
@@ -605,7 +605,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// Returns an iterator along the chain of parents of this node.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &ResolvedNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &ResolvedNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.ancestors(),
             NodeOrToken::Token(it) => it.parent().ancestors(),
@@ -614,7 +614,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// Return the leftmost token in the subtree of this element.
     #[inline]
-    pub fn first_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn first_token(&self) -> Option<&ResolvedToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.first_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -623,7 +623,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// Return the rightmost token in the subtree of this element.
     #[inline]
-    pub fn last_token(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn last_token(&self) -> Option<&ResolvedToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.last_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -632,7 +632,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// The tree element to the right of this one, i.e. the next child of this element's parent after this element.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.next_sibling_or_token(),
             NodeOrToken::Token(it) => it.next_sibling_or_token(),
@@ -641,7 +641,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
 
     /// The tree element to the left of this one, i.e. the previous child of this element's parent after this element.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'_, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.prev_sibling_or_token(),
             NodeOrToken::Token(it) => it.prev_sibling_or_token(),
@@ -649,7 +649,7 @@ impl<L: Language, D> ResolvedElement<L, D> {
     }
 }
 
-impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
+impl<'a, S: Syntax, D> ResolvedElementRef<'a, S, D> {
     /// The range this element covers in the source text, in bytes.
     #[inline]
     pub fn text_range(&self) -> TextRange {
@@ -670,7 +670,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// The kind of this element in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
         match self {
             NodeOrToken::Node(it) => it.kind(),
             NodeOrToken::Token(it) => it.kind(),
@@ -679,7 +679,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// The parent node of this element, except if this element is the root.
     #[inline]
-    pub fn parent(&self) -> Option<&'a ResolvedNode<L, D>> {
+    pub fn parent(&self) -> Option<&'a ResolvedNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.parent(),
             NodeOrToken::Token(it) => Some(it.parent()),
@@ -688,7 +688,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// Returns an iterator along the chain of parents of this node.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &'a ResolvedNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &'a ResolvedNode<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.ancestors(),
             NodeOrToken::Token(it) => it.parent().ancestors(),
@@ -697,7 +697,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// Return the leftmost token in the subtree of this element.
     #[inline]
-    pub fn first_token(&self) -> Option<&'a ResolvedToken<L, D>> {
+    pub fn first_token(&self) -> Option<&'a ResolvedToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.first_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -706,7 +706,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// Return the rightmost token in the subtree of this element.
     #[inline]
-    pub fn last_token(&self) -> Option<&'a ResolvedToken<L, D>> {
+    pub fn last_token(&self) -> Option<&'a ResolvedToken<S, D>> {
         match self {
             NodeOrToken::Node(it) => it.last_token(),
             NodeOrToken::Token(it) => Some(it),
@@ -715,7 +715,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// The tree element to the right of this one, i.e. the next child of this element's parent after this element.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'a, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<ResolvedElementRef<'a, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.next_sibling_or_token(),
             NodeOrToken::Token(it) => it.next_sibling_or_token(),
@@ -724,7 +724,7 @@ impl<'a, L: Language, D> ResolvedElementRef<'a, L, D> {
 
     /// The tree element to the left of this one, i.e. the previous child of this element's parent after this element.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'a, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<ResolvedElementRef<'a, S, D>> {
         match self {
             NodeOrToken::Node(it) => it.prev_sibling_or_token(),
             NodeOrToken::Token(it) => it.prev_sibling_or_token(),

cstree/src/syntax/text.rs

@@ -6,7 +6,7 @@ use crate::{
     interning::{Resolver, TokenKey},
     syntax::{SyntaxNode, SyntaxToken},
     text::{TextRange, TextSize},
-    Language,
+    Syntax,
 };
 
 /// An efficient representation of the text that is covered by a [`SyntaxNode`], i.e. the combined
@@ -21,9 +21,9 @@ use crate::{
 /// # use cstree::testing::*;
 /// # use cstree::syntax::ResolvedNode;
 /// #
-/// fn parse_float_literal(s: &str) -> ResolvedNode<MyLanguage> {
+/// fn parse_float_literal(s: &str) -> ResolvedNode<MySyntax> {
 ///     // parsing...
-/// #     let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+/// #     let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
 /// #     builder.start_node(Float);
 /// #     builder.token(Float, s);
 /// #     builder.finish_node();
@@ -41,14 +41,14 @@ use crate::{
 /// assert_eq!(sub, "748");
 /// ```
 #[derive(Clone)]
-pub struct SyntaxText<'n, 'i, I: ?Sized, L: Language, D: 'static = ()> {
+pub struct SyntaxText<'n, 'i, I: ?Sized, S: Syntax, D: 'static = ()> {
-    node:     &'n SyntaxNode<L, D>,
+    node:     &'n SyntaxNode<S, D>,
     range:    TextRange,
     resolver: &'i I,
 }
 
-impl<'n, 'i, I: Resolver<TokenKey> + ?Sized, L: Language, D> SyntaxText<'n, 'i, I, L, D> {
+impl<'n, 'i, I: Resolver<TokenKey> + ?Sized, S: Syntax, D> SyntaxText<'n, 'i, I, S, D> {
-    pub(crate) fn new(node: &'n SyntaxNode<L, D>, resolver: &'i I) -> Self {
+    pub(crate) fn new(node: &'n SyntaxNode<S, D>, resolver: &'i I) -> Self {
         let range = node.text_range();
         SyntaxText { node, range, resolver }
     }
@@ -188,7 +188,7 @@ impl<'n, 'i, I: Resolver<TokenKey> + ?Sized, L: Language, D> SyntaxText<'n, 'i,
         self.fold_chunks((), |(), chunk| f(chunk))
     }
 
-    fn tokens_with_ranges(&self) -> impl Iterator<Item = (&SyntaxToken<L, D>, TextRange)> {
+    fn tokens_with_ranges(&self) -> impl Iterator<Item = (&SyntaxToken<S, D>, TextRange)> {
         let text_range = self.range;
         self.node
             .descendants_with_tokens()
@@ -208,25 +208,25 @@ fn found<T>(res: Result<(), T>) -> Option<T> {
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> fmt::Debug for SyntaxText<'_, '_, I, L, D> {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> fmt::Debug for SyntaxText<'_, '_, I, S, D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         fmt::Debug::fmt(&self.to_string(), f)
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> fmt::Display for SyntaxText<'_, '_, I, L, D> {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> fmt::Display for SyntaxText<'_, '_, I, S, D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.try_for_each_chunk(|chunk| fmt::Display::fmt(chunk, f))
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> From<SyntaxText<'_, '_, I, L, D>> for String {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> From<SyntaxText<'_, '_, I, S, D>> for String {
-    fn from(text: SyntaxText<'_, '_, I, L, D>) -> String {
+    fn from(text: SyntaxText<'_, '_, I, S, D>) -> String {
         text.to_string()
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> PartialEq<str> for SyntaxText<'_, '_, I, L, D> {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> PartialEq<str> for SyntaxText<'_, '_, I, S, D> {
     fn eq(&self, mut rhs: &str) -> bool {
         self.try_for_each_chunk(|chunk| {
             if !rhs.starts_with(chunk) {
@@ -240,33 +240,33 @@ impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> PartialEq<str> for SyntaxTe
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> PartialEq<SyntaxText<'_, '_, I, L, D>> for str {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> PartialEq<SyntaxText<'_, '_, I, S, D>> for str {
-    fn eq(&self, rhs: &SyntaxText<'_, '_, I, L, D>) -> bool {
+    fn eq(&self, rhs: &SyntaxText<'_, '_, I, S, D>) -> bool {
         rhs == self
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> PartialEq<&'_ str> for SyntaxText<'_, '_, I, L, D> {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> PartialEq<&'_ str> for SyntaxText<'_, '_, I, S, D> {
     fn eq(&self, rhs: &&str) -> bool {
         self == *rhs
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> PartialEq<SyntaxText<'_, '_, I, L, D>> for &'_ str {
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> PartialEq<SyntaxText<'_, '_, I, S, D>> for &'_ str {
-    fn eq(&self, rhs: &SyntaxText<'_, '_, I, L, D>) -> bool {
+    fn eq(&self, rhs: &SyntaxText<'_, '_, I, S, D>) -> bool {
         rhs == self
     }
 }
 
-impl<'n1, 'i1, 'n2, 'i2, I1, I2, L1, L2, D1, D2> PartialEq<SyntaxText<'n2, 'i2, I2, L2, D2>>
+impl<'n1, 'i1, 'n2, 'i2, I1, I2, S1, S2, D1, D2> PartialEq<SyntaxText<'n2, 'i2, I2, S2, D2>>
-    for SyntaxText<'n1, 'i1, I1, L1, D1>
+    for SyntaxText<'n1, 'i1, I1, S1, D1>
 where
-    L1: Language,
+    S1: Syntax,
-    L2: Language,
+    S2: Syntax,
     I1: Resolver<TokenKey> + ?Sized,
     I2: Resolver<TokenKey> + ?Sized,
 {
-    fn eq(&self, other: &SyntaxText<'_, '_, I2, L2, D2>) -> bool {
+    fn eq(&self, other: &SyntaxText<'_, '_, I2, S2, D2>) -> bool {
         if self.range.len() != other.range.len() {
             return false;
         }
@@ -278,21 +278,21 @@ where
     }
 }
 
-fn zip_texts<'it1, 'it2, It1, It2, I1, I2, L1, L2, D1, D2>(
+fn zip_texts<'it1, 'it2, It1, It2, I1, I2, S1, S2, D1, D2>(
     xs: &mut It1,
     ys: &mut It2,
     resolver_x: &I1,
     resolver_y: &I2,
 ) -> Option<()>
 where
-    It1: Iterator<Item = (&'it1 SyntaxToken<L1, D1>, TextRange)>,
+    It1: Iterator<Item = (&'it1 SyntaxToken<S1, D1>, TextRange)>,
-    It2: Iterator<Item = (&'it2 SyntaxToken<L2, D2>, TextRange)>,
+    It2: Iterator<Item = (&'it2 SyntaxToken<S2, D2>, TextRange)>,
     I1: Resolver<TokenKey> + ?Sized,
     I2: Resolver<TokenKey> + ?Sized,
     D1: 'static,
     D2: 'static,
-    L1: Language + 'it1,
+    S1: Syntax + 'it1,
-    L2: Language + 'it2,
+    S2: Syntax + 'it2,
 {
     let mut x = xs.next()?;
     let mut y = ys.next()?;
@@ -314,7 +314,7 @@ where
     }
 }
 
-impl<I: Resolver<TokenKey> + ?Sized, L: Language, D> Eq for SyntaxText<'_, '_, I, L, D> {}
+impl<I: Resolver<TokenKey> + ?Sized, S: Syntax, D> Eq for SyntaxText<'_, '_, I, S, D> {}
 
 mod private {
     use std::ops;
@@ -383,40 +383,38 @@ mod tests {
 
     use super::*;
 
-    #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-    pub enum TestLang {}
+    #[repr(transparent)]
-    impl Language for TestLang {
+    pub struct SyntaxKind(u32);
-        type Kind = RawSyntaxKind;
 
-        fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
+    impl Syntax for SyntaxKind {
-            raw
+        fn from_raw(raw: RawSyntaxKind) -> Self {
+            Self(raw.0)
         }
 
-        fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
+        fn into_raw(self) -> RawSyntaxKind {
-            kind
+            RawSyntaxKind(self.0)
         }
 
-        fn static_text(kind: Self::Kind) -> Option<&'static str> {
+        fn static_text(self) -> Option<&'static str> {
-            if kind == RawSyntaxKind(1) {
+            match self.0 {
-                Some("{")
+                1 => Some("{"),
-            } else if kind == RawSyntaxKind(2) {
+                2 => Some("}"),
-                Some("}")
+                _ => None,
-            } else {
-                None
             }
         }
     }
 
-    fn build_tree(chunks: &[&str]) -> (SyntaxNode<TestLang, ()>, impl Resolver<TokenKey>) {
+    fn build_tree(chunks: &[&str]) -> (SyntaxNode<SyntaxKind, ()>, impl Resolver<TokenKey>) {
-        let mut builder: GreenNodeBuilder<TestLang> = GreenNodeBuilder::new();
+        let mut builder: GreenNodeBuilder<SyntaxKind> = GreenNodeBuilder::new();
-        builder.start_node(RawSyntaxKind(62));
+        builder.start_node(SyntaxKind(62));
         for &chunk in chunks.iter() {
             let kind = match chunk {
                 "{" => 1,
                 "}" => 2,
                 _ => 3,
             };
-            builder.token(RawSyntaxKind(kind), chunk);
+            builder.token(SyntaxKind(kind), chunk);
         }
         builder.finish_node();
         let (node, cache) = builder.finish();

cstree/src/syntax/token.rs

@@ -12,18 +12,18 @@ use crate::{
     green::{GreenNode, GreenToken},
     interning::{Resolver, TokenKey},
     traversal::Direction,
-    Language, RawSyntaxKind,
+    RawSyntaxKind, Syntax,
 };
 
 /// Syntax tree token.
 #[derive(Debug)]
-pub struct SyntaxToken<L: Language, D: 'static = ()> {
+pub struct SyntaxToken<S: Syntax, D: 'static = ()> {
-    parent: SyntaxNode<L, D>,
+    parent: SyntaxNode<S, D>,
     index:  u32,
     offset: TextSize,
 }
 
-impl<L: Language, D> Clone for SyntaxToken<L, D> {
+impl<S: Syntax, D> Clone for SyntaxToken<S, D> {
     fn clone(&self) -> Self {
         Self {
             parent: self.parent.clone(),
@@ -33,7 +33,7 @@ impl<L: Language, D> Clone for SyntaxToken<L, D> {
     }
 }
 
-impl<L: Language, D> Hash for SyntaxToken<L, D> {
+impl<S: Syntax, D> Hash for SyntaxToken<S, D> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.parent.hash(state);
         self.index.hash(state);
@@ -41,15 +41,15 @@ impl<L: Language, D> Hash for SyntaxToken<L, D> {
     }
 }
 
-impl<L: Language, D> PartialEq for SyntaxToken<L, D> {
+impl<S: Syntax, D> PartialEq for SyntaxToken<S, D> {
-    fn eq(&self, other: &SyntaxToken<L, D>) -> bool {
+    fn eq(&self, other: &SyntaxToken<S, D>) -> bool {
         self.parent == other.parent && self.index == other.index && self.offset == other.offset
     }
 }
 
-impl<L: Language, D> Eq for SyntaxToken<L, D> {}
+impl<S: Syntax, D> Eq for SyntaxToken<S, D> {}
 
-impl<L: Language, D> SyntaxToken<L, D> {
+impl<S: Syntax, D> SyntaxToken<S, D> {
     /// Writes this token's [`Debug`](fmt::Debug) representation into the given `target`.
     pub fn write_debug<R>(&self, resolver: &R, target: &mut impl fmt::Write) -> fmt::Result
     where
@@ -113,7 +113,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// Turns this token into a [`ResolvedToken`](crate::syntax::ResolvedToken), but only if there is a resolver
     /// associated with this tree.
     #[inline]
-    pub fn try_resolved(&self) -> Option<&ResolvedToken<L, D>> {
+    pub fn try_resolved(&self) -> Option<&ResolvedToken<S, D>> {
         // safety: we only coerce if `resolver` exists
         self.resolver().map(|_| unsafe { ResolvedToken::coerce_ref(self) })
     }
@@ -122,13 +122,13 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// # Panics
     /// If there is no resolver associated with this tree.
     #[inline]
-    pub fn resolved(&self) -> &ResolvedToken<L, D> {
+    pub fn resolved(&self) -> &ResolvedToken<S, D> {
         self.try_resolved().expect("tried to resolve a node without resolver")
     }
 }
 
-impl<L: Language, D> SyntaxToken<L, D> {
+impl<S: Syntax, D> SyntaxToken<S, D> {
-    pub(super) fn new(parent: &SyntaxNode<L, D>, index: u32, offset: TextSize) -> SyntaxToken<L, D> {
+    pub(super) fn new(parent: &SyntaxNode<S, D>, index: u32, offset: TextSize) -> SyntaxToken<S, D> {
         Self {
             parent: parent.clone_uncounted(),
             index,
@@ -164,8 +164,8 @@ impl<L: Language, D> SyntaxToken<L, D> {
 
     /// The kind of this token in terms of your language.
     #[inline]
-    pub fn kind(&self) -> L::Kind {
+    pub fn kind(&self) -> S {
-        L::kind_from_raw(self.syntax_kind())
+        S::from_raw(self.syntax_kind())
     }
 
     /// The range this token covers in the source text, in bytes.
@@ -187,17 +187,17 @@ impl<L: Language, D> SyntaxToken<L, D> {
         self.static_text().or_else(|| self.green().text(resolver)).unwrap()
     }
 
-    /// If the [syntax kind](Language::Kind) of this token always represents the same text, returns
+    /// If the [syntax kind](Syntax) of this token always represents the same text, returns
     /// that text.
     ///
     /// # Examples
     /// If there is a syntax kind `Plus` that represents just the `+` operator and we implement
-    /// [`Language::static_text`] for it, we can retrieve this text in the resulting syntax tree.
+    /// [`Syntax::static_text`] for it, we can retrieve this text in the resulting syntax tree.
     ///
     /// ```
     /// # use cstree::testing::*;
     /// # use cstree::build::*;
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// # builder.start_node(Root);
     /// # builder.token(Identifier, "x");
     /// # builder.token(Whitespace, " ");
@@ -206,7 +206,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// # builder.token(Int, "3");
     /// # builder.finish_node();
     /// let tree = parse(&mut builder, "x + 3");
-    /// # let tree: SyntaxNode<MyLanguage> = SyntaxNode::new_root(builder.finish().0);
+    /// # let tree: SyntaxNode<MySyntax> = SyntaxNode::new_root(builder.finish().0);
     /// let plus = tree
     ///     .children_with_tokens()
     ///     .nth(2) // `x`, then a space, then `+`
@@ -217,7 +217,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// ```
     #[inline(always)]
     pub fn static_text(&self) -> Option<&'static str> {
-        L::static_text(self.kind())
+        S::static_text(self.kind())
     }
 
     /// Returns `true` if `self` and `other` represent equal source text.
@@ -235,7 +235,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// # Examples
     /// ```
     /// # use cstree::testing::*;
-    /// let mut builder: GreenNodeBuilder<MyLanguage> = GreenNodeBuilder::new();
+    /// let mut builder: GreenNodeBuilder<MySyntax> = GreenNodeBuilder::new();
     /// # builder.start_node(Root);
     /// # builder.token(Identifier, "x");
     /// # builder.token(Whitespace, " ");
@@ -247,7 +247,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// # builder.token(Int, "3");
     /// # builder.finish_node();
     /// let tree = parse(&mut builder, "x + x + 3");
-    /// # let tree: SyntaxNode<MyLanguage> = SyntaxNode::new_root(builder.finish().0);
+    /// # let tree: SyntaxNode<MySyntax> = SyntaxNode::new_root(builder.finish().0);
     /// let mut tokens = tree.children_with_tokens();
     /// let tokens = tokens.by_ref();
     /// let first_x = tokens.next().unwrap().into_token().unwrap();
@@ -303,14 +303,14 @@ impl<L: Language, D> SyntaxToken<L, D> {
     ///     interner,
     ///     type_table: TypeTable{ /* stuff */},
     /// };
-    /// let mut builder: GreenNodeBuilder<MyLanguage, TokenInterner> =
+    /// let mut builder: GreenNodeBuilder<MySyntax, TokenInterner> =
     ///     GreenNodeBuilder::with_interner(&mut state.interner);
     /// # let input = "";
     /// # builder.start_node(Root);
     /// # builder.token(Identifier, "x");
     /// # builder.finish_node();
     /// let tree = parse(&mut builder, "x");
-    /// # let tree: SyntaxNode<MyLanguage> = SyntaxNode::new_root(builder.finish().0);
+    /// # let tree: SyntaxNode<MySyntax> = SyntaxNode::new_root(builder.finish().0);
     /// let type_table = &state.type_table;
     /// let ident = tree
     ///     .children_with_tokens()
@@ -339,26 +339,26 @@ impl<L: Language, D> SyntaxToken<L, D> {
 
     /// The parent node of this token.
     #[inline]
-    pub fn parent(&self) -> &SyntaxNode<L, D> {
+    pub fn parent(&self) -> &SyntaxNode<S, D> {
         &self.parent
     }
 
     /// Returns an iterator along the chain of parents of this token.
     #[inline]
-    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<L, D>> {
+    pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode<S, D>> {
         self.parent().ancestors()
     }
 
     /// The tree element to the right of this one, i.e. the next child of this token's parent after this token.
     #[inline]
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn next_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         self.parent()
             .next_child_or_token_after(self.index as usize, self.text_range().end())
     }
 
     /// The tree element to the left of this one, i.e. the previous child of this token's parent after this token.
     #[inline]
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, L, D>> {
+    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElementRef<'_, S, D>> {
         self.parent()
             .prev_child_or_token_before(self.index as usize, self.text_range().start())
     }
@@ -367,8 +367,8 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// token's parent's children from this token on to the left or the right.
     /// The first item in the iterator will always be this token.
     #[inline]
-    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = SyntaxElementRef<'_, L, D>> {
+    pub fn siblings_with_tokens(&self, direction: Direction) -> impl Iterator<Item = SyntaxElementRef<'_, S, D>> {
-        let me: SyntaxElementRef<'_, L, D> = self.into();
+        let me: SyntaxElementRef<'_, S, D> = self.into();
         iter::successors(Some(me), move |el| match direction {
             Direction::Next => el.next_sibling_or_token(),
             Direction::Prev => el.prev_sibling_or_token(),
@@ -378,7 +378,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// Returns the next token in the tree.
     /// This is not necessary a direct sibling of this token, but will always be further right in the tree.
     #[inline]
-    pub fn next_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn next_token(&self) -> Option<&SyntaxToken<S, D>> {
         match self.next_sibling_or_token() {
             Some(element) => element.first_token(),
             None => self
@@ -392,7 +392,7 @@ impl<L: Language, D> SyntaxToken<L, D> {
     /// Returns the previous token in the tree.
     /// This is not necessary a direct sibling of this token, but will always be further left in the tree.
     #[inline]
-    pub fn prev_token(&self) -> Option<&SyntaxToken<L, D>> {
+    pub fn prev_token(&self) -> Option<&SyntaxToken<S, D>> {
         match self.prev_sibling_or_token() {
             Some(element) => element.last_token(),
             None => self

cstree/tests/it/basic.rs

@@ -7,7 +7,7 @@ use cstree::{
 };
 
 fn build_tree<D>(root: &Element<'_>) -> (SyntaxNode<D>, impl Resolver) {
-    let mut builder: GreenNodeBuilder<TestLang> = GreenNodeBuilder::new();
+    let mut builder: GreenNodeBuilder<SyntaxKind> = GreenNodeBuilder::new();
     build_recursive(root, &mut builder, 0);
     let (node, cache) = builder.finish();
     (SyntaxNode::new_root(node), cache.unwrap().into_interner().unwrap())
@@ -36,19 +36,19 @@ fn create() {
     let tree = two_level_tree();
     let (tree, resolver) = build_tree::<()>(&tree);
     assert_eq!(tree.syntax_kind(), RawSyntaxKind(0));
-    assert_eq!(tree.kind(), RawSyntaxKind(0));
+    assert_eq!(tree.kind(), SyntaxKind(0));
     {
         let leaf1_0 = tree.children().nth(1).unwrap().children_with_tokens().next().unwrap();
         let leaf1_0 = leaf1_0.into_token().unwrap();
         assert_eq!(leaf1_0.syntax_kind(), RawSyntaxKind(5));
-        assert_eq!(leaf1_0.kind(), RawSyntaxKind(5));
+        assert_eq!(leaf1_0.kind(), SyntaxKind(5));
         assert_eq!(leaf1_0.resolve_text(&resolver), "1.0");
         assert_eq!(leaf1_0.text_range(), TextRange::at(6.into(), 3.into()));
     }
     {
         let node2 = tree.children().nth(2).unwrap();
         assert_eq!(node2.syntax_kind(), RawSyntaxKind(6));
-        assert_eq!(node2.kind(), RawSyntaxKind(6));
+        assert_eq!(node2.kind(), SyntaxKind(6));
         assert_eq!(node2.children_with_tokens().count(), 3);
         assert_eq!(node2.resolve_text(&resolver), "2.02.12.2");
     }
@@ -58,7 +58,7 @@ fn create() {
 fn token_text_eq() {
     let tree = tree_with_eq_tokens();
     let (tree, _) = build_tree::<()>(&tree);
-    assert_eq!(tree.kind(), RawSyntaxKind(0));
+    assert_eq!(tree.kind(), SyntaxKind(0));
 
     let leaf0_0 = tree.children().next().unwrap().children_with_tokens().next().unwrap();
     let leaf0_0 = leaf0_0.into_token().unwrap();
@@ -150,7 +150,7 @@ fn inline_resolver() {
         assert_eq!(leaf1_0.text(), "1.0");
         assert_eq!(leaf1_0.text_range(), TextRange::at(6.into(), 3.into()));
         assert_eq!(format!("{}", leaf1_0), leaf1_0.text());
-        assert_eq!(format!("{:?}", leaf1_0), "RawSyntaxKind(5)@6..9 \"1.0\"");
+        assert_eq!(format!("{:?}", leaf1_0), "SyntaxKind(5)@6..9 \"1.0\"");
     }
     {
         let node2 = tree.children().nth(2).unwrap();
@@ -158,13 +158,13 @@ fn inline_resolver() {
         let resolver = node2.resolver();
         assert_eq!(node2.resolve_text(resolver.as_ref()), node2.text());
         assert_eq!(format!("{}", node2).as_str(), node2.text());
-        assert_eq!(format!("{:?}", node2), "RawSyntaxKind(6)@9..18");
+        assert_eq!(format!("{:?}", node2), "SyntaxKind(6)@9..18");
         assert_eq!(
             format!("{:#?}", node2),
-            r#"RawSyntaxKind(6)@9..18
+            r#"SyntaxKind(6)@9..18
-  RawSyntaxKind(7)@9..12 "2.0"
+  SyntaxKind(7)@9..12 "2.0"
-  RawSyntaxKind(8)@12..15 "2.1"
+  SyntaxKind(8)@12..15 "2.1"
-  RawSyntaxKind(9)@15..18 "2.2"
+  SyntaxKind(9)@15..18 "2.2"
 "#
         );
     }
@@ -182,5 +182,5 @@ fn assert_debug_display() {
     f::<cstree::util::NodeOrToken<String, u128>>();
 
     fn dbg<T: fmt::Debug>() {}
-    dbg::<GreenNodeBuilder<'static, 'static, TestLang>>();
+    dbg::<GreenNodeBuilder<'static, 'static, SyntaxKind>>();
 }

cstree/tests/it/main.rs

@@ -0,0 +1,80 @@
+mod basic;
+mod regressions;
+mod sendsync;
+#[cfg(feature = "serialize")]
+mod serde;
+
+use cstree::{
+    build::{GreenNodeBuilder, NodeCache},
+    green::GreenNode,
+    interning::Interner,
+    RawSyntaxKind, Syntax,
+};
+
+pub type SyntaxNode<D = ()> = cstree::syntax::SyntaxNode<SyntaxKind, D>;
+pub type SyntaxToken<D = ()> = cstree::syntax::SyntaxToken<SyntaxKind, D>;
+pub type SyntaxElement<D = ()> = cstree::syntax::SyntaxElement<SyntaxKind, D>;
+pub type SyntaxElementRef<'a, D = ()> = cstree::syntax::SyntaxElementRef<'a, SyntaxKind, D>;
+
+pub type ResolvedNode<D = ()> = cstree::syntax::ResolvedNode<SyntaxKind, D>;
+pub type ResolvedToken<D = ()> = cstree::syntax::ResolvedToken<SyntaxKind, D>;
+pub type ResolvedElement<D = ()> = cstree::syntax::ResolvedElement<SyntaxKind, D>;
+pub type ResolvedElementRef<'a, D = ()> = cstree::syntax::ResolvedElementRef<'a, SyntaxKind, D>;
+
+#[derive(Debug)]
+pub enum Element<'s> {
+    Node(Vec<Element<'s>>),
+    Token(&'s str),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(transparent)]
+pub struct SyntaxKind(u32);
+
+impl Syntax for SyntaxKind {
+    fn from_raw(raw: RawSyntaxKind) -> Self {
+        Self(raw.0)
+    }
+
+    fn into_raw(self) -> RawSyntaxKind {
+        RawSyntaxKind(self.0)
+    }
+
+    fn static_text(self) -> Option<&'static str> {
+        None
+    }
+}
+
+pub fn build_tree_with_cache<I>(root: &Element<'_>, cache: &mut NodeCache<'_, I>) -> GreenNode
+where
+    I: Interner,
+{
+    let mut builder: GreenNodeBuilder<SyntaxKind, I> = GreenNodeBuilder::with_cache(cache);
+    build_recursive(root, &mut builder, 0);
+    let (node, cache) = builder.finish();
+    assert!(cache.is_none());
+    node
+}
+
+pub fn build_recursive<I>(
+    root: &Element<'_>,
+    builder: &mut GreenNodeBuilder<'_, '_, SyntaxKind, I>,
+    mut from: u32,
+) -> u32
+where
+    I: Interner,
+{
+    match root {
+        Element::Node(children) => {
+            builder.start_node(SyntaxKind(from));
+            for child in children {
+                from = build_recursive(child, builder, from + 1);
+            }
+            builder.finish_node();
+        }
+        Element::Token(text) => {
+            builder.token(SyntaxKind(from), text);
+        }
+    }
+    from
+}

cstree/tests/it/regressions.rs

@@ -0,0 +1,21 @@
+use cstree::Syntax;
+
+#[test]
+fn empty_tree_arc() {
+    // this test is not here for the test itself, but to run it through MIRI, who complained about out-of-bound
+    // `ThinArc` pointers for a root `GreenNode` with no children
+
+    use cstree::{build::GreenNodeBuilder, syntax::SyntaxNode};
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+    #[repr(u32)]
+    enum SyntaxKind {
+        Root,
+    }
+
+    let mut builder: GreenNodeBuilder<SyntaxKind> = GreenNodeBuilder::new();
+    builder.start_node(SyntaxKind::Root);
+    builder.finish_node();
+    let (green, _) = builder.finish();
+    let root: SyntaxNode<SyntaxKind> = SyntaxNode::new_root(green);
+    assert_eq!(root.kind(), SyntaxKind::Root);
+}

cstree/tests/it/sendsync.rs

@@ -3,7 +3,7 @@
 use crossbeam_utils::thread::scope;
 use std::{thread, time::Duration};
 
-use super::{build_recursive, Element, ResolvedNode, SyntaxNode, TestLang};
+use super::{build_recursive, Element, ResolvedNode, SyntaxKind, SyntaxNode};
 use cstree::build::GreenNodeBuilder;
 
 // Excercise the multi-threaded interner when the corresponding feature is enabled.
@@ -12,12 +12,12 @@ use cstree::build::GreenNodeBuilder;
 use cstree::interning::{new_threaded_interner, MultiThreadedTokenInterner};
 
 #[cfg(not(feature = "multi_threaded_interning"))]
-fn get_builder() -> GreenNodeBuilder<'static, 'static, TestLang> {
+fn get_builder() -> GreenNodeBuilder<'static, 'static, SyntaxKind> {
     GreenNodeBuilder::new()
 }
 
 #[cfg(feature = "multi_threaded_interning")]
-fn get_builder() -> GreenNodeBuilder<'static, 'static, TestLang, MultiThreadedTokenInterner> {
+fn get_builder() -> GreenNodeBuilder<'static, 'static, SyntaxKind, MultiThreadedTokenInterner> {
     let interner = new_threaded_interner();
     GreenNodeBuilder::from_interner(interner)
 }

cstree/tests/it/serde.rs

@@ -1,6 +1,6 @@
 use crate::{build_recursive, build_tree_with_cache, ResolvedNode};
 
-use super::{Element, SyntaxNode, TestLang};
+use super::{Element, SyntaxKind, SyntaxNode};
 use cstree::{
     build::{GreenNodeBuilder, NodeCache},
     interning::new_interner,
@@ -225,7 +225,7 @@ fn three_level_tree() -> Element<'static> {
 }
 
 fn build_tree(root: Element<'_>) -> ResolvedNode<String> {
-    let mut builder: GreenNodeBuilder<TestLang> = GreenNodeBuilder::new();
+    let mut builder: GreenNodeBuilder<SyntaxKind> = GreenNodeBuilder::new();
     build_recursive(&root, &mut builder, 0);
     let (node, cache) = builder.finish();
     SyntaxNode::new_root_with_resolver(node, cache.unwrap().into_interner().unwrap())

test_suite/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name                   = "cstree_test_suite"
+publish                = false
+version                = "0.0.0"
+edition.workspace      = true
+authors.workspace      = true
+license.workspace      = true
+repository.workspace   = true
+readme.workspace       = true
+rust-version.workspace = true
+
+[dependencies]
+cstree = { path = "../cstree", features = ["derive"] }
+
+[dev-dependencies]
+trybuild = { version = "1.0.80", features = ["diff"] }

test_suite/tests/derive.rs

@@ -0,0 +1,22 @@
+use cstree::{RawSyntaxKind, Syntax};
+
+#[test]
+fn basic() {
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+    #[repr(u32)]
+    pub enum SyntaxKind {
+        A,
+        #[static_text("b")]
+        B,
+    }
+    pub type MySyntax = SyntaxKind;
+
+    assert_eq!(MySyntax::into_raw(SyntaxKind::A), RawSyntaxKind(0));
+    assert_eq!(MySyntax::into_raw(SyntaxKind::B), RawSyntaxKind(1));
+
+    assert_eq!(MySyntax::from_raw(RawSyntaxKind(0)), SyntaxKind::A);
+    assert_eq!(MySyntax::from_raw(RawSyntaxKind(1)), SyntaxKind::B);
+
+    assert!(MySyntax::static_text(SyntaxKind::A).is_none());
+    assert_eq!(MySyntax::static_text(SyntaxKind::B), Some("b"));
+}

test_suite/tests/ui.rs

@@ -0,0 +1,6 @@
+#[test]
+#[cfg_attr(miri, ignore)]
+fn ui() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/**/*.rs");
+}

test_suite/tests/ui/repr/missing_repr.rs

@@ -0,0 +1,10 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+pub enum SyntaxKind {
+    A,
+    #[static_text("b")]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/repr/missing_repr.stderr

@@ -0,0 +1,9 @@
+error: syntax kind definitions must be `#[repr(u32)]` to derive `Syntax`
+ --> tests/ui/repr/missing_repr.rs:4:1
+  |
+4 | / pub enum SyntaxKind {
+5 | |     A,
+6 | |     #[static_text("b")]
+7 | |     B,
+8 | | }
+  | |_^

test_suite/tests/ui/repr/wrong_repr_c.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(C)]
+pub enum SyntaxKind {
+    A,
+    #[static_text("b")]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/repr/wrong_repr_c.stderr

@@ -0,0 +1,10 @@
+error: syntax kind definitions must be `#[repr(u32)]` to derive `Syntax`
+ --> tests/ui/repr/wrong_repr_c.rs:4:1
+  |
+4 | / #[repr(C)]
+5 | | pub enum SyntaxKind {
+6 | |     A,
+7 | |     #[static_text("b")]
+8 | |     B,
+9 | | }
+  | |_^

test_suite/tests/ui/repr/wrong_repr_u16.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u16)]
+pub enum SyntaxKind {
+    A,
+    #[static_text("b")]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/repr/wrong_repr_u16.stderr

@@ -0,0 +1,10 @@
+error: syntax kind definitions must be `#[repr(u32)]` to derive `Syntax`
+ --> tests/ui/repr/wrong_repr_u16.rs:4:1
+  |
+4 | / #[repr(u16)]
+5 | | pub enum SyntaxKind {
+6 | |     A,
+7 | |     #[static_text("b")]
+8 | |     B,
+9 | | }
+  | |_^

test_suite/tests/ui/static_text/empty_expr.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u32)]
+pub enum SyntaxKind {
+    A,
+    #[static_text()]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/static_text/empty_expr.stderr

@@ -0,0 +1,11 @@
+error: argument to `static_text` must be a string literal: `#[static_text("...")]`
+ --> tests/ui/static_text/empty_expr.rs:7:7
+  |
+7 |     #[static_text()]
+  |       ^^^^^^^^^^^^^
+
+error: unexpected end of input, expected string literal
+ --> tests/ui/static_text/empty_expr.rs:7:19
+  |
+7 |     #[static_text()]
+  |                   ^

test_suite/tests/ui/static_text/missing_text.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u32)]
+pub enum SyntaxKind {
+    A,
+    #[static_text]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/static_text/missing_text.stderr

@@ -0,0 +1,5 @@
+error: missing text for `static_text`: try `#[static_text("...")]`
+ --> tests/ui/static_text/missing_text.rs:7:5
+  |
+7 |     #[static_text]
+  |     ^^^^^^^^^^^^^^

test_suite/tests/ui/static_text/non_expr.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u32)]
+pub enum SyntaxKind {
+    A,
+    #[static_text(SyntaxKind)]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/static_text/non_expr.stderr

@@ -0,0 +1,11 @@
+error: argument to `static_text` must be a string literal: `#[static_text("...")]`
+ --> tests/ui/static_text/non_expr.rs:7:7
+  |
+7 |     #[static_text(SyntaxKind)]
+  |       ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: expected string literal
+ --> tests/ui/static_text/non_expr.rs:7:19
+  |
+7 |     #[static_text(SyntaxKind)]
+  |                   ^^^^^^^^^^

test_suite/tests/ui/static_text/non_string_expr.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u32)]
+pub enum SyntaxKind {
+    A,
+    #[static_text(foo + 3)]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/static_text/non_string_expr.stderr

@@ -0,0 +1,11 @@
+error: argument to `static_text` must be a string literal: `#[static_text("...")]`
+ --> tests/ui/static_text/non_string_expr.rs:7:7
+  |
+7 |     #[static_text(foo + 3)]
+  |       ^^^^^^^^^^^^^^^^^^^^
+
+error: expected string literal
+ --> tests/ui/static_text/non_string_expr.rs:7:19
+  |
+7 |     #[static_text(foo + 3)]
+  |                   ^^^

test_suite/tests/ui/static_text/text_assigned.rs

@@ -0,0 +1,11 @@
+use cstree::Syntax;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Syntax)]
+#[repr(u32)]
+pub enum SyntaxKind {
+    A,
+    #[static_text = "b"]
+    B,
+}
+
+fn main() {}

test_suite/tests/ui/static_text/text_assigned.stderr

@@ -0,0 +1,5 @@
+error: `static_text` takes the text as a function argument: `#[static_text("...")]`
+ --> tests/ui/static_text/text_assigned.rs:7:5
+  |
+7 |     #[static_text = "b"]
+  |     ^^^^^^^^^^^^^^^^^^^^

tests/it/main.rs

@@ -1,77 +0,0 @@
-mod basic;
-mod regressions;
-mod sendsync;
-#[cfg(feature = "serialize")]
-mod serde;
-
-use cstree::{
-    build::{GreenNodeBuilder, NodeCache},
-    green::GreenNode,
-    interning::Interner,
-    Language, RawSyntaxKind,
-};
-
-pub type SyntaxNode<D = ()> = cstree::syntax::SyntaxNode<TestLang, D>;
-pub type SyntaxToken<D = ()> = cstree::syntax::SyntaxToken<TestLang, D>;
-pub type SyntaxElement<D = ()> = cstree::syntax::SyntaxElement<TestLang, D>;
-pub type SyntaxElementRef<'a, D = ()> = cstree::syntax::SyntaxElementRef<'a, TestLang, D>;
-
-pub type ResolvedNode<D = ()> = cstree::syntax::ResolvedNode<TestLang, D>;
-pub type ResolvedToken<D = ()> = cstree::syntax::ResolvedToken<TestLang, D>;
-pub type ResolvedElement<D = ()> = cstree::syntax::ResolvedElement<TestLang, D>;
-pub type ResolvedElementRef<'a, D = ()> = cstree::syntax::ResolvedElementRef<'a, TestLang, D>;
-
-#[derive(Debug)]
-pub enum Element<'s> {
-    Node(Vec<Element<'s>>),
-    Token(&'s str),
-}
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub enum TestLang {}
-impl Language for TestLang {
-    type Kind = RawSyntaxKind;
-
-    fn kind_from_raw(raw: RawSyntaxKind) -> Self::Kind {
-        raw
-    }
-
-    fn kind_to_raw(kind: Self::Kind) -> RawSyntaxKind {
-        kind
-    }
-
-    fn static_text(_kind: Self::Kind) -> Option<&'static str> {
-        None
-    }
-}
-
-pub fn build_tree_with_cache<I>(root: &Element<'_>, cache: &mut NodeCache<'_, I>) -> GreenNode
-where
-    I: Interner,
-{
-    let mut builder: GreenNodeBuilder<TestLang, I> = GreenNodeBuilder::with_cache(cache);
-    build_recursive(root, &mut builder, 0);
-    let (node, cache) = builder.finish();
-    assert!(cache.is_none());
-    node
-}
-
-pub fn build_recursive<L, I>(root: &Element<'_>, builder: &mut GreenNodeBuilder<'_, '_, L, I>, mut from: u32) -> u32
-where
-    L: Language<Kind = RawSyntaxKind>,
-    I: Interner,
-{
-    match root {
-        Element::Node(children) => {
-            builder.start_node(RawSyntaxKind(from));
-            for child in children {
-                from = build_recursive(child, builder, from + 1);
-            }
-            builder.finish_node();
-        }
-        Element::Token(text) => {
-            builder.token(RawSyntaxKind(from), text);
-        }
-    }
-    from
-}

tests/it/regressions.rs

@@ -1,38 +0,0 @@
-#[test]
-fn empty_tree_arc() {
-    // this test is not here for the test itself, but to run it through MIRI, who complained about out-of-bound
-    // `ThinArc` pointers for a root `GreenNode` with no children
-
-    use cstree::{build::GreenNodeBuilder, syntax::SyntaxNode};
-    #[allow(non_camel_case_types)]
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-    #[repr(u32)]
-    enum SyntaxKind {
-        Root,
-    }
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-    enum Lang {}
-    impl cstree::Language for Lang {
-        // ...
-        type Kind = SyntaxKind;
-
-        fn kind_from_raw(raw: cstree::RawSyntaxKind) -> Self::Kind {
-            assert!(raw.0 <= SyntaxKind::Root as u32);
-            unsafe { std::mem::transmute::<u32, SyntaxKind>(raw.0) }
-        }
-
-        fn kind_to_raw(kind: Self::Kind) -> cstree::RawSyntaxKind {
-            cstree::RawSyntaxKind(kind as u32)
-        }
-
-        fn static_text(_kind: Self::Kind) -> Option<&'static str> {
-            None
-        }
-    }
-    let mut builder: GreenNodeBuilder<Lang> = GreenNodeBuilder::new();
-    builder.start_node(SyntaxKind::Root);
-    builder.finish_node();
-    let (green, _) = builder.finish();
-    let root: SyntaxNode<Lang> = SyntaxNode::new_root(green);
-    assert_eq!(root.kind(), SyntaxKind::Root);
-}