From 712f3988f963888e7a1f1856cd7622eca54c782c Mon Sep 17 00:00:00 2001
From: Kevin Amado <kamadorueda@gmail.com>
Date: Sun, 27 Feb 2022 16:38:00 -0500
Subject: [PATCH] refactor: apply

---
 src/alejandra_engine/src/parsers/apply.rs | 63 +++++++++++++----------
 src/alejandra_engine/src/rules/apply.rs   | 45 ++++++++--------
 2 files changed, 58 insertions(+), 50 deletions(-)

diff --git a/src/alejandra_engine/src/parsers/apply.rs b/src/alejandra_engine/src/parsers/apply.rs
index 726333e..de59a57 100644
--- a/src/alejandra_engine/src/parsers/apply.rs
+++ b/src/alejandra_engine/src/parsers/apply.rs
@@ -1,38 +1,45 @@
 use std::collections::LinkedList;
 
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub(crate) struct Apply {
-    pub left:     Option<rnix::SyntaxElement>,
-    pub comments: LinkedList<String>,
-    pub newline:  bool,
-    pub right:    Option<rnix::SyntaxElement>,
+    pub left_expression:         rnix::SyntaxElement,
+    pub comments_after_left:     LinkedList<String>,
+    pub has_newlines_after_left: bool,
+    pub right_expression:        rnix::SyntaxElement,
 }
 
-pub(crate) fn parse(
-    build_ctx: &crate::builder::BuildCtx,
-    node: &rnix::SyntaxNode,
-) -> Apply {
-    let mut apply = Apply::default();
+impl Apply {
+    pub(crate) fn parse(
+        build_ctx: &crate::builder::BuildCtx,
+        node: &rnix::SyntaxNode,
+    ) -> Apply {
+        let mut children = crate::children::Children::new(build_ctx, node);
 
-    let mut children = crate::children::Children::new(build_ctx, node);
+        // left_expression
+        let left_expression = children.get_next().unwrap();
 
-    // left
-    apply.left = Some(children.get_next().unwrap());
-
-    // /**/
-    children.drain_trivia(|element| match element {
-        crate::children::Trivia::Comment(text) => {
-            apply.comments.push_back(text);
-        }
-        crate::children::Trivia::Whitespace(text) => {
-            if !apply.newline {
-                apply.newline = crate::utils::count_newlines(&text) > 0;
+        // comments_after_left
+        // has_newlines_after_left
+        let mut comments_after_left = LinkedList::new();
+        let mut has_newlines_after_left = false;
+        children.drain_trivia(|element| match element {
+            crate::children::Trivia::Comment(text) => {
+                comments_after_left.push_back(text);
             }
+            crate::children::Trivia::Whitespace(text) => {
+                has_newlines_after_left = has_newlines_after_left
+                    || crate::utils::count_newlines(&text) > 0;
+            }
+        });
+
+        // right_expression
+        let right_expression = children.get_next().unwrap();
+
+        Apply {
+            left_expression,
+            comments_after_left,
+            has_newlines_after_left,
+            right_expression,
         }
-    });
-
-    // right
-    apply.right = Some(children.get_next().unwrap());
-
-    apply
+    }
 }
diff --git a/src/alejandra_engine/src/rules/apply.rs b/src/alejandra_engine/src/rules/apply.rs
index 6ed33f5..4497075 100644
--- a/src/alejandra_engine/src/rules/apply.rs
+++ b/src/alejandra_engine/src/rules/apply.rs
@@ -4,36 +4,35 @@ pub(crate) fn rule(
 ) -> std::collections::LinkedList<crate::builder::Step> {
     let mut steps = std::collections::LinkedList::new();
 
-    let apply = crate::parsers::apply::parse(build_ctx, node);
+    let parsed = crate::parsers::apply::Apply::parse(build_ctx, node);
 
-    let vertical =
-        build_ctx.vertical || apply.newline || !apply.comments.is_empty();
+    let vertical = build_ctx.vertical
+        || !parsed.comments_after_left.is_empty()
+        || parsed.has_newlines_after_left;
 
-    // left
-    let element = apply.left.unwrap();
+    // left_expression
     if vertical {
-        steps.push_back(crate::builder::Step::FormatWider(element));
+        steps.push_back(crate::builder::Step::FormatWider(
+            parsed.left_expression,
+        ));
     } else {
-        steps.push_back(crate::builder::Step::Format(element));
+        steps.push_back(crate::builder::Step::Format(parsed.left_expression));
     }
 
-    // /**/
-    let comments = !apply.comments.is_empty();
-    if comments {
-        for text in apply.comments {
-            steps.push_back(crate::builder::Step::NewLine);
-            steps.push_back(crate::builder::Step::Pad);
-            steps.push_back(crate::builder::Step::Comment(text));
-        }
+    // comments_after_left
+    let has_comments_after_left = !parsed.comments_after_left.is_empty();
+    for text in parsed.comments_after_left {
+        steps.push_back(crate::builder::Step::NewLine);
+        steps.push_back(crate::builder::Step::Pad);
+        steps.push_back(crate::builder::Step::Comment(text));
     }
 
-    // right
-    let element = apply.right.unwrap();
+    // right_expression
     if vertical {
-        if !apply.newline
-            && !comments
+        if !has_comments_after_left
+            && !parsed.has_newlines_after_left
             && matches!(
-                element.kind(),
+                parsed.right_expression.kind(),
                 rnix::SyntaxKind::NODE_ATTR_SET
                     | rnix::SyntaxKind::NODE_LIST
                     | rnix::SyntaxKind::NODE_PAREN
@@ -45,10 +44,12 @@ pub(crate) fn rule(
             steps.push_back(crate::builder::Step::NewLine);
             steps.push_back(crate::builder::Step::Pad);
         };
-        steps.push_back(crate::builder::Step::FormatWider(element));
+        steps.push_back(crate::builder::Step::FormatWider(
+            parsed.right_expression,
+        ));
     } else {
         steps.push_back(crate::builder::Step::Whitespace);
-        steps.push_back(crate::builder::Step::Format(element));
+        steps.push_back(crate::builder::Step::Format(parsed.right_expression));
     }
 
     steps