Hash based on binding name and shadow counter

crates/ra_ide_api/src/snapshots/tests__highlighting.snap

@@ -1,5 +1,5 @@
 ---
-created: "2019-05-25T10:53:54.439877Z"
+created: "2019-05-25T11:24:53.486036Z"
 creator: insta@0.8.1
 source: crates/ra_ide_api/src/syntax_highlighting.rs
 expression: result
@@ -20,7 +20,7 @@ Ok(
             range: [32; 35),
             tag: "variable",
             id: Some(
-                461893210254723387,
+                8465336196764640996,
             ),
         },
         HighlightedRange {
@@ -32,7 +32,7 @@ Ok(
             range: [46; 47),
             tag: "variable",
             id: Some(
-                8312289520117458465,
+                176272420896316891,
             ),
         },
         HighlightedRange {
@@ -49,7 +49,7 @@ Ok(
             range: [62; 63),
             tag: "variable",
             id: Some(
-                4497542318236667727,
+                15061637676198917049,
             ),
         },
         HighlightedRange {
@@ -66,7 +66,7 @@ Ok(
             range: [76; 79),
             tag: "variable",
             id: Some(
-                4506850079084802999,
+                14077410872302487760,
             ),
         },
         HighlightedRange {
@@ -78,7 +78,7 @@ Ok(
             range: [80; 81),
             tag: "variable",
             id: Some(
-                16968185728268100018,
+                8379786015941272633,
             ),
         },
         HighlightedRange {
@@ -105,7 +105,7 @@ Ok(
             range: [131; 135),
             tag: "variable",
             id: Some(
-                14467718814232352107,
+                5766414492220109266,
             ),
         },
         HighlightedRange {

crates/ra_ide_api/src/snapshots/tests__rainbow_highlighting.snap

@@ -1,5 +1,5 @@
 ---
-created: "2019-05-25T10:25:13.898113Z"
+created: "2019-05-25T11:21:56.117898Z"
 creator: insta@0.8.1
 source: crates/ra_ide_api/src/syntax_highlighting.rs
 expression: result
@@ -15,7 +15,7 @@ Ok(
             range: [4; 8),
             tag: "variable",
             id: Some(
-                17119830160611610240,
+                5766414492220109266,
             ),
         },
         HighlightedRange {
@@ -27,7 +27,7 @@ Ok(
             range: [21; 26),
             tag: "variable",
             id: Some(
-                2744494144922727377,
+                15975256018338854530,
             ),
         },
         HighlightedRange {
@@ -44,14 +44,14 @@ Ok(
             range: [46; 47),
             tag: "variable",
             id: Some(
-                10375904121795371996,
+                176272420896316891,
             ),
         },
         HighlightedRange {
             range: [50; 55),
             tag: "variable",
             id: Some(
-                2744494144922727377,
+                15975256018338854530,
             ),
         },
         HighlightedRange {
@@ -68,14 +68,14 @@ Ok(
             range: [77; 78),
             tag: "variable",
             id: Some(
-                8228548264153724449,
+                15061637676198917049,
             ),
         },
         HighlightedRange {
             range: [81; 86),
             tag: "variable",
             id: Some(
-                2744494144922727377,
+                15975256018338854530,
             ),
         },
         HighlightedRange {
@@ -83,5 +83,46 @@ Ok(
             tag: "text",
             id: None,
         },
+        HighlightedRange {
+            range: [105; 108),
+            tag: "keyword",
+            id: None,
+        },
+        HighlightedRange {
+            range: [109; 110),
+            tag: "variable",
+            id: Some(
+                1714508680417729339,
+            ),
+        },
+        HighlightedRange {
+            range: [113; 134),
+            tag: "string",
+            id: None,
+        },
+        HighlightedRange {
+            range: [140; 143),
+            tag: "keyword",
+            id: None,
+        },
+        HighlightedRange {
+            range: [144; 145),
+            tag: "variable",
+            id: Some(
+                15953336624848413466,
+            ),
+        },
+        HighlightedRange {
+            range: [148; 149),
+            tag: "variable",
+            id: Some(
+                1714508680417729339,
+            ),
+        },
+        HighlightedRange {
+            range: [150; 159),
+            tag: "text",
+            id: None,
+        },
     ],
 )

crates/ra_ide_api/src/syntax_highlighting.rs

@@ -1,6 +1,6 @@
-use rustc_hash::FxHashSet;
+use rustc_hash::{FxHashSet, FxHashMap};
 
-use ra_syntax::{ast, AstNode, TextRange, Direction, SyntaxKind, SyntaxKind::*, SyntaxElement, T};
+use ra_syntax::{ast, AstNode, TextRange, Direction, SmolStr, SyntaxKind, SyntaxKind::*, SyntaxElement, T};
 use ra_db::SourceDatabase;
 use ra_prof::profile;
 
@@ -43,6 +43,8 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
 
     // Visited nodes to handle highlighting priorities
     let mut highlighted: FxHashSet<SyntaxElement> = FxHashSet::default();
+    let mut bindings_shadow_count: FxHashMap<SmolStr, u32> = FxHashMap::default();
+
     let mut res = Vec::new();
     for node in source_file.syntax().descendants_with_tokens() {
         if highlighted.contains(&node) {
@@ -77,7 +79,11 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
                         Some(Def(ModuleDef::Trait(_))) => ("type", None),
                         Some(Def(ModuleDef::TypeAlias(_))) => ("type", None),
                         Some(SelfType(_)) => ("type", None),
-                        Some(Pat(ptr)) => ("variable", Some(hash(ptr.syntax_node_ptr().range()))),
+                        Some(Pat(ptr)) => ("variable", Some(hash({
+                            let text = ptr.syntax_node_ptr().to_node(&source_file.syntax()).text().to_smol_string();
+                            let shadow_count = bindings_shadow_count.entry(text.clone()).or_default();
+                            (text, shadow_count)
+                        }))),
                         Some(SelfParam(_)) => ("type", None),
                         Some(GenericParam(_)) => ("type", None),
                         None => ("text", None),
@@ -88,7 +94,12 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
             }
             NAME => {
                 if let Some(name) = node.as_ast_node::<ast::Name>() {
-                    ("variable", Some(hash(name.syntax().range())))
+                    ("variable", Some(hash({
+                        let text = name.syntax().text().to_smol_string();
+                        let shadow_count = bindings_shadow_count.entry(text.clone()).or_insert(1);
+                        *shadow_count += 1;
+                        (text, shadow_count)
+                    })))
                 } else {
                     ("text", None)
                 }
@@ -240,16 +251,19 @@ fn main() {
     }
 
     #[test]
-    fn test_sematic_highlighting() {
+    fn test_rainbow_highlighting() {
         let (analysis, file_id) = single_file(
             r#"
 fn main() {
     let hello = "hello";
     let x = hello.to_string();
     let y = hello.to_string();
+
+    let x = "other color please!";
+    let y = x.to_string();
 }"#,
         );
         let result = analysis.highlight(file_id);
-        assert_debug_snapshot_matches!("sematic_highlighting", result);
+        assert_debug_snapshot_matches!("rainbow_highlighting", result);
     }
 }

crates/ra_syntax/src/syntax_text.rs

@@ -1,6 +1,6 @@
 use std::{fmt, ops::{self, Bound}};
 
-use crate::{SyntaxNode, TextRange, TextUnit, SyntaxElement};
+use crate::{SmolStr, SyntaxNode, TextRange, TextUnit, SyntaxElement};
 
 #[derive(Clone)]
 pub struct SyntaxText<'a> {
@@ -34,6 +34,11 @@ impl<'a> SyntaxText<'a> {
         self.chunks().collect()
     }
 
+    pub fn to_smol_string(&self) -> SmolStr {
+        // TODO: `impl iter::FromIterator<&str> for SmolStr`
+        self.to_string().into()
+    }
+
     pub fn contains(&self, c: char) -> bool {
         self.chunks().any(|it| it.contains(c))
     }