LibSQL: Add a syntax highlighter

Userland/Libraries/LibSQL/SyntaxHighlighter.cpp

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2021, Dylan Katz <dykatz@uw.edu>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Debug.h>
+#include <LibGUI/TextEditor.h>
+#include <LibGfx/Font.h>
+#include <LibGfx/Palette.h>
+#include <LibSQL/Lexer.h>
+#include <LibSQL/SyntaxHighlighter.h>
+
+namespace SQL {
+
+static Syntax::TextStyle style_for_token_type(const Gfx::Palette& palette, TokenType type)
+{
+    switch (Token::category(type)) {
+    case TokenCategory::Keyword:
+        return { palette.syntax_keyword(), true };
+    case TokenCategory::Identifier:
+        return { palette.syntax_identifier(), false };
+    case TokenCategory::Number:
+        return { palette.syntax_number(), false };
+    case TokenCategory::Blob:
+    case TokenCategory::String:
+        return { palette.syntax_string(), false };
+    case TokenCategory::Operator:
+        return { palette.syntax_operator(), false };
+    case TokenCategory::Punctuation:
+        return { palette.syntax_punctuation(), false };
+    case TokenCategory::Invalid:
+    default:
+        return { palette.base_text(), false };
+    }
+}
+
+bool SyntaxHighlighter::is_identifier(void* token) const
+{
+    auto sql_token = static_cast<SQL::TokenType>(reinterpret_cast<size_t>(token));
+    return sql_token == SQL::TokenType::Identifier;
+}
+
+void SyntaxHighlighter::rehighlight(const Palette& palette)
+{
+    auto text = m_client->get_text();
+
+    SQL::Lexer lexer(text);
+
+    Vector<GUI::TextDocumentSpan> spans;
+
+    auto append_token = [&](StringView str, const SQL::Token& token) {
+        if (str.is_empty())
+            return;
+
+        GUI::TextPosition position { token.line_number() - 1, token.line_column() - 1 };
+        for (size_t i = 0; i < str.length() - 1; ++i) {
+            if (str[i] == '\n') {
+                position.set_line(position.line() + 1);
+                position.set_column(0);
+            } else
+                position.set_column(position.column() + 1);
+        }
+
+        GUI::TextDocumentSpan span;
+        span.range.set_start({ token.line_number() - 1, token.line_column() - 1 });
+        span.range.set_end({ position.line(), position.column() });
+        auto style = style_for_token_type(palette, token.type());
+        span.attributes.color = style.color;
+        span.attributes.bold = style.bold;
+        span.data = reinterpret_cast<void*>(static_cast<size_t>(token.type()));
+        spans.append(span);
+
+        dbgln_if(SYNTAX_HIGHLIGHTING_DEBUG, "{} @ '{}' {}:{} - {}:{}",
+            token.name(),
+            token.value(),
+            span.range.start().line(), span.range.start().column(),
+            span.range.end().line(), span.range.end().column());
+    };
+
+    bool was_eof = false;
+    for (auto token = lexer.next(); !was_eof; token = lexer.next()) {
+        append_token(token.value(), token);
+
+        if (token.type() == SQL::TokenType::Eof)
+            was_eof = true;
+    }
+
+    m_client->do_set_spans(move(spans));
+
+    m_has_brace_buddies = false;
+    highlight_matching_token_pair();
+
+    m_client->do_update();
+}
+
+Vector<SyntaxHighlighter::MatchingTokenPair> SyntaxHighlighter::matching_token_pairs() const
+{
+    static Vector<SyntaxHighlighter::MatchingTokenPair> pairs;
+    if (pairs.is_empty()) {
+        pairs.append({ reinterpret_cast<void*>(TokenType::ParenOpen), reinterpret_cast<void*>(TokenType::ParenClose) });
+    }
+    return pairs;
+}
+
+bool SyntaxHighlighter::token_types_equal(void* token1, void* token2) const
+{
+    return static_cast<TokenType>(reinterpret_cast<size_t>(token1)) == static_cast<TokenType>(reinterpret_cast<size_t>(token2));
+}
+
+SyntaxHighlighter::~SyntaxHighlighter()
+{
+}
+
+}