Colorize Rust code as HTML

4 files changed, 131 insertions, 152 deletions

diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index f78348f74..d3456d5b2 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -462,6 +462,11 @@ impl Analysis {
         self.with_db(|db| syntax_highlighting::highlight(db, file_id))
     }
 
+    /// Computes syntax highlighting for the given file.
+    pub fn highlight_as_html(&self, file_id: FileId) -> Cancelable<String> {
+        self.with_db(|db| syntax_highlighting::highlight_as_html(db, file_id))
+    }
+
     /// Computes completions at the given position.
     pub fn completions(&self, position: FilePosition) -> Cancelable<Option<Vec<CompletionItem>>> {
         self.with_db(|db| completion::completions(db, position).map(Into::into))
diff --git a/crates/ra_ide_api/src/snapshots/highlighting.html b/crates/ra_ide_api/src/snapshots/highlighting.html
new file mode 100644
index 000000000..bfc0a67b1
--- /dev/null
+++ b/crates/ra_ide_api/src/snapshots/highlighting.html
@@ -0,0 +1,45 @@
+
+<style>
+pre {
+    color: #DCDCCC;
+    background-color: #3F3F3F;
+    font-size: 22px;
+}
+
+.comment   { color: #7F9F7F; }
+.string    { color: #CC9393; }
+.function  { color: #93E0E3; }
+.parameter { color: #94BFF3; }
+.builtin   { color: #DD6718; }
+.text      { color: #DCDCCC; }
+.attribute { color: #BFEBBF; }
+.literal   { color: #DFAF8F; }
+.macro     { color: #DFAF8F; }
+
+.keyword           { color: #F0DFAF; }
+.keyword\.unsafe  { color: #F0DFAF; font-weight: bold; }
+.keyword\.control { color: #DC8CC3; }
+
+</style>
+<pre><code>
+<span class="attribute">#</span><span class="attribute">[</span><span class="attribute">derive</span><span class="attribute">(</span><span class="attribute">Clone</span><span class="attribute">,</span><span class="attribute"> </span><span class="attribute">Debug</span><span class="attribute">)</span><span class="attribute">]</span>
+<span class="keyword">struct</span> <span class="function">Foo</span> {
+    <span class="keyword">pub</span> <span class="function">x</span>: <span class="text">i32</span>,
+    <span class="keyword">pub</span> <span class="function">y</span>: <span class="text">i32</span>,
+}
+
+<span class="keyword">fn</span> <span class="function">foo</span>&lt;<span class="type function">T</span>&gt;() -&gt; <span class="type">T</span> {
+    <span class="macro">unimplemented</span><span class="macro">!</span>();
+}
+
+<span class="comment">// comment</span>
+<span class="keyword">fn</span> <span class="function">main</span>() {
+    <span class="macro">println</span><span class="macro">!</span>(<span class="string">"Hello, {}!"</span>, <span class="literal">92</span>);
+
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="function">vec</span> = <span class="text">Vec</span>::<span class="text">new</span>();
+    <span class="keyword.control">if</span> <span class="keyword">true</span> {
+        <span class="text">vec</span>.<span class="text">push</span>(<span class="type">Foo</span> { <span class="field">x</span>: <span class="literal">0</span>, <span class="field">y</span>: <span class="literal">1</span> });
+    }
+    <span class="keyword.unsafe">unsafe</span> { <span class="text">vec</span>.<span class="text">set_len</span>(<span class="literal">0</span>); }
+}
+</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide_api/src/snapshots/tests__highlighting.snap b/crates/ra_ide_api/src/snapshots/tests__highlighting.snap
deleted file mode 100644
index 9c60aed2a..000000000
--- a/crates/ra_ide_api/src/snapshots/tests__highlighting.snap
+++ /dev/null
@@ -1,146 +0,0 @@
----
-created: "2019-05-23T22:23:35.242742395Z"
-creator: [email protected]
-source: crates/ra_ide_api/src/syntax_highlighting.rs
-expression: result
----
-Ok(
-    [
-        HighlightedRange {
-            range: [1; 24),
-            tag: "attribute",
-        },
-        HighlightedRange {
-            range: [25; 31),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [32; 35),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [42; 45),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [46; 47),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [49; 52),
-            tag: "text",
-        },
-        HighlightedRange {
-            range: [58; 61),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [62; 63),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [65; 68),
-            tag: "text",
-        },
-        HighlightedRange {
-            range: [73; 75),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [76; 79),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [80; 81),
-            tag: "type",
-        },
-        HighlightedRange {
-            range: [80; 81),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [88; 89),
-            tag: "type",
-        },
-        HighlightedRange {
-            range: [96; 110),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [117; 127),
-            tag: "comment",
-        },
-        HighlightedRange {
-            range: [128; 130),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [131; 135),
-            tag: "function",
-        },
-        HighlightedRange {
-            range: [145; 153),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [154; 166),
-            tag: "string",
-        },
-        HighlightedRange {
-            range: [168; 170),
-            tag: "literal",
-        },
-        HighlightedRange {
-            range: [178; 181),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [182; 185),
-            tag: "keyword",
-        },
-        HighlightedRange {
-            range: [186; 189),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [197; 200),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [192; 195),
-            tag: "text",
-        },
-        HighlightedRange {
-            range: [208; 211),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [212; 216),
-            tag: "macro",
-        },
-        HighlightedRange {
-            range: [226; 227),
-            tag: "literal",
-        },
-        HighlightedRange {
-            range: [232; 233),
-            tag: "literal",
-        },
-        HighlightedRange {
-            range: [242; 248),
-            tag: "keyword.unsafe",
-        },
-        HighlightedRange {
-            range: [251; 254),
-            tag: "text",
-        },
-        HighlightedRange {
-            range: [255; 262),
-            tag: "text",
-        },
-        HighlightedRange {
-            range: [263; 264),
-            tag: "literal",
-        },
-    ],
-)
diff --git a/crates/ra_ide_api/src/syntax_highlighting.rs b/crates/ra_ide_api/src/syntax_highlighting.rs
index 7bba7a550..87e053364 100644
--- a/crates/ra_ide_api/src/syntax_highlighting.rs
+++ b/crates/ra_ide_api/src/syntax_highlighting.rs
@@ -114,10 +114,79 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
     res
 }
 
+pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId) -> String {
+    let source_file = db.parse(file_id);
+
+    let mut ranges = highlight(db, file_id);
+    ranges.sort_by_key(|it| it.range.start());
+    // quick non-optimal heuristic to intersect token ranges and highlighted ranges
+    let mut frontier = 0;
+    let mut could_intersect: Vec<&HighlightedRange> = Vec::new();
+
+    let mut buf = String::new();
+    buf.push_str(&STYLE);
+    buf.push_str("<pre><code>");
+    let tokens = source_file.syntax().descendants_with_tokens().filter_map(|it| it.as_token());
+    for token in tokens {
+        could_intersect.retain(|it| token.range().start() <= it.range.end());
+        while let Some(r) = ranges.get(frontier) {
+            if r.range.start() <= token.range().end() {
+                could_intersect.push(r);
+                frontier += 1;
+            } else {
+                break;
+            }
+        }
+        let text = html_escape(&token.text());
+        let classes = could_intersect
+            .iter()
+            .filter(|it| token.range().is_subrange(&it.range))
+            .map(|it| it.tag)
+            .collect::<Vec<_>>();
+        if classes.is_empty() {
+            buf.push_str(&text);
+        } else {
+            let classes = classes.join(" ");
+            buf.push_str(&format!("<span class=\"{}\">{}</span>", classes, text));
+        }
+    }
+    buf.push_str("</code></pre>");
+    buf
+}
+
+//FIXME: like, real html escaping
+fn html_escape(text: &str) -> String {
+    text.replace("<", "&lt;").replace(">", "&gt;")
+}
+
+const STYLE: &str = "
+<style>
+pre {
+    color: #DCDCCC;
+    background-color: #3F3F3F;
+    font-size: 22px;
+}
+
+.comment   { color: #7F9F7F; }
+.string    { color: #CC9393; }
+.function  { color: #93E0E3; }
+.parameter { color: #94BFF3; }
+.builtin   { color: #DD6718; }
+.text      { color: #DCDCCC; }
+.attribute { color: #BFEBBF; }
+.literal   { color: #DFAF8F; }
+.macro     { color: #DFAF8F; }
+
+.keyword           { color: #F0DFAF; }
+.keyword\\.unsafe  { color: #F0DFAF; font-weight: bold; }
+.keyword\\.control { color: #DC8CC3; }
+
+</style>
+";
+
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot_matches;
-
+    use test_utils::{project_dir, read_text, assert_eq_text};
     use crate::mock_analysis::single_file;
 
     #[test]
@@ -135,15 +204,21 @@ fn foo<T>() -> T {
 }
 
 // comment
-fn main() {}
+fn main() {
     println!("Hello, {}!", 92);
 
     let mut vec = Vec::new();
-    vec.push(Foo { x: 0, y: 1 });
+    if true {
+        vec.push(Foo { x: 0, y: 1 });
+    }
     unsafe { vec.set_len(0); }
+}
 "#,
         );
-        let result = analysis.highlight(file_id);
-        assert_debug_snapshot_matches!("highlighting", result);
+        let dst_file = project_dir().join("crates/ra_ide_api/src/snapshots/highlighting.html");
+        let actual_html = &analysis.highlight_as_html(file_id).unwrap();
+        let expected_html = &read_text(&dst_file);
+        // std::fs::write(dst_file, &actual_html).unwrap();
+        assert_eq_text!(expected_html, actual_html);
     }
 }