1 files changed, 75 insertions, 6 deletions

diff --git a/crates/ra_ide_api/src/syntax_highlighting.rs b/crates/ra_ide_api/src/syntax_highlighting.rs
index fdd87bcff..a0c5e78ad 100644
--- a/crates/ra_ide_api/src/syntax_highlighting.rs
+++ b/crates/ra_ide_api/src/syntax_highlighting.rs
@@ -1,12 +1,81 @@
-use ra_syntax::AstNode;
+use rustc_hash::FxHashSet;
+
+use ra_syntax::{ast, AstNode, TextRange, Direction, SyntaxKind::*};
 use ra_db::SourceDatabase;
 
-use crate::{
-    FileId, HighlightedRange,
-    db::RootDatabase,
-};
+use crate::{FileId, db::RootDatabase};
+
+#[derive(Debug)]
+pub struct HighlightedRange {
+    pub range: TextRange,
+    pub tag: &'static str,
+}
 
 pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRange> {
     let source_file = db.parse(file_id);
-    ra_ide_api_light::highlight(source_file.syntax())
+
+    // Visited nodes to handle highlighting priorities
+    let mut highlighted = FxHashSet::default();
+    let mut res = Vec::new();
+    for node in source_file.syntax().descendants() {
+        if highlighted.contains(&node) {
+            continue;
+        }
+        let tag = match node.kind() {
+            COMMENT => "comment",
+            STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => "string",
+            ATTR => "attribute",
+            NAME_REF => "text",
+            NAME => "function",
+            INT_NUMBER | FLOAT_NUMBER | CHAR | BYTE => "literal",
+            LIFETIME => "parameter",
+            k if k.is_keyword() => "keyword",
+            _ => {
+                if let Some(macro_call) = ast::MacroCall::cast(node) {
+                    if let Some(path) = macro_call.path() {
+                        if let Some(segment) = path.segment() {
+                            if let Some(name_ref) = segment.name_ref() {
+                                highlighted.insert(name_ref.syntax());
+                                let range_start = name_ref.syntax().range().start();
+                                let mut range_end = name_ref.syntax().range().end();
+                                for sibling in path.syntax().siblings(Direction::Next) {
+                                    match sibling.kind() {
+                                        EXCL | IDENT => range_end = sibling.range().end(),
+                                        _ => (),
+                                    }
+                                }
+                                res.push(HighlightedRange {
+                                    range: TextRange::from_to(range_start, range_end),
+                                    tag: "macro",
+                                })
+                            }
+                        }
+                    }
+                }
+                continue;
+            }
+        };
+        res.push(HighlightedRange { range: node.range(), tag })
+    }
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_debug_snapshot_matches;
+
+    use crate::mock_analysis::single_file;
+
+    #[test]
+    fn test_highlighting() {
+        let (analysis, file_id) = single_file(
+            r#"
+// comment
+fn main() {}
+    println!("Hello, {}!", 92);
+"#,
+        );
+        let result = analysis.highlight(file_id);
+        assert_debug_snapshot_matches!("highlighting", result);
+    }
 }