3 files changed, 414 insertions, 0 deletions

diff --git a/crates/ra_ide/src/syntax_highlighting/html.rs b/crates/ra_ide/src/syntax_highlighting/html.rs
new file mode 100644
index 000000000..e13766c9d
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/html.rs
@@ -0,0 +1,106 @@
+//! Renders a bit of code as HTML.
+
+use ra_db::SourceDatabase;
+use ra_syntax::AstNode;
+
+use crate::{FileId, HighlightedRange, RootDatabase};
+
+use super::highlight;
+
+pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId, rainbow: bool) -> String {
+    let parse = db.parse(file_id);
+
+    fn rainbowify(seed: u64) -> String {
+        use rand::prelude::*;
+        let mut rng = SmallRng::seed_from_u64(seed);
+        format!(
+            "hsl({h},{s}%,{l}%)",
+            h = rng.gen_range::<u16, _, _>(0, 361),
+            s = rng.gen_range::<u16, _, _>(42, 99),
+            l = rng.gen_range::<u16, _, _>(40, 91),
+        )
+    }
+
+    let mut ranges = highlight(db, file_id, None);
+    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 = parse.tree().syntax().descendants_with_tokens().filter_map(|it| it.into_token());
+    for token in tokens {
+        could_intersect.retain(|it| token.text_range().start() <= it.range.end());
+        while let Some(r) = ranges.get(frontier) {
+            if r.range.start() <= token.text_range().end() {
+                could_intersect.push(r);
+                frontier += 1;
+            } else {
+                break;
+            }
+        }
+        let text = html_escape(&token.text());
+        let ranges = could_intersect
+            .iter()
+            .filter(|it| token.text_range().is_subrange(&it.range))
+            .collect::<Vec<_>>();
+        if ranges.is_empty() {
+            buf.push_str(&text);
+        } else {
+            let classes = ranges
+                .iter()
+                .map(|it| it.highlight.to_string().replace('.', " "))
+                .collect::<Vec<_>>()
+                .join(" ");
+            let binding_hash = ranges.first().and_then(|x| x.binding_hash);
+            let color = match (rainbow, binding_hash) {
+                (true, Some(hash)) => format!(
+                    " data-binding-hash=\"{}\" style=\"color: {};\"",
+                    hash,
+                    rainbowify(hash)
+                ),
+                _ => "".into(),
+            };
+            buf.push_str(&format!("<span class=\"{}\"{}>{}</span>", classes, color, 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>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.variable           { color: #DCDCCC; }
+.mutable            { text-decoration: underline; }
+
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+</style>
+";
diff --git a/crates/ra_ide/src/syntax_highlighting/tags.rs b/crates/ra_ide/src/syntax_highlighting/tags.rs
new file mode 100644
index 000000000..8835a5de2
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/tags.rs
@@ -0,0 +1,175 @@
+//! Defines token tags we use for syntax highlighting.
+//! A tag is not unlike a CSS class.
+
+use std::{fmt, ops};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct Highlight {
+    pub tag: HighlightTag,
+    pub modifiers: HighlightModifiers,
+}
+
+#[derive(Default, Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct HighlightModifiers(u32);
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub enum HighlightTag {
+    Attribute,
+    BuiltinType,
+    ByteLiteral,
+    CharLiteral,
+    Comment,
+    Constant,
+    Enum,
+    EnumVariant,
+    Field,
+    Function,
+    Keyword,
+    Lifetime,
+    Macro,
+    Module,
+    NumericLiteral,
+    SelfType,
+    Static,
+    StringLiteral,
+    Struct,
+    Trait,
+    TypeAlias,
+    TypeParam,
+    Union,
+    Local,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[repr(u8)]
+pub enum HighlightModifier {
+    /// Used with keywords like `if` and `break`.
+    Control = 0,
+    /// `foo` in `fn foo(x: i32)` is a definition, `foo` in `foo(90 + 2)` is
+    /// not.
+    Definition,
+    Mutable,
+    Unsafe,
+}
+
+impl HighlightTag {
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightTag::Attribute => "attribute",
+            HighlightTag::BuiltinType => "builtin_type",
+            HighlightTag::ByteLiteral => "byte_literal",
+            HighlightTag::CharLiteral => "char_literal",
+            HighlightTag::Comment => "comment",
+            HighlightTag::Constant => "constant",
+            HighlightTag::Enum => "enum",
+            HighlightTag::EnumVariant => "enum_variant",
+            HighlightTag::Field => "field",
+            HighlightTag::Function => "function",
+            HighlightTag::Keyword => "keyword",
+            HighlightTag::Lifetime => "lifetime",
+            HighlightTag::Macro => "macro",
+            HighlightTag::Module => "module",
+            HighlightTag::NumericLiteral => "numeric_literal",
+            HighlightTag::SelfType => "self_type",
+            HighlightTag::Static => "static",
+            HighlightTag::StringLiteral => "string_literal",
+            HighlightTag::Struct => "struct",
+            HighlightTag::Trait => "trait",
+            HighlightTag::TypeAlias => "type_alias",
+            HighlightTag::TypeParam => "type_param",
+            HighlightTag::Union => "union",
+            HighlightTag::Local => "variable",
+        }
+    }
+}
+
+impl fmt::Display for HighlightTag {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_str(), f)
+    }
+}
+
+impl HighlightModifier {
+    const ALL: &'static [HighlightModifier] = &[
+        HighlightModifier::Control,
+        HighlightModifier::Definition,
+        HighlightModifier::Mutable,
+        HighlightModifier::Unsafe,
+    ];
+
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightModifier::Control => "control",
+            HighlightModifier::Definition => "declaration",
+            HighlightModifier::Mutable => "mutable",
+            HighlightModifier::Unsafe => "unsafe",
+        }
+    }
+
+    fn mask(self) -> u32 {
+        1 << (self as u32)
+    }
+}
+
+impl fmt::Display for HighlightModifier {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_str(), f)
+    }
+}
+
+impl fmt::Display for Highlight {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.tag)?;
+        for modifier in self.modifiers.iter() {
+            write!(f, ".{}", modifier)?
+        }
+        Ok(())
+    }
+}
+
+impl From<HighlightTag> for Highlight {
+    fn from(tag: HighlightTag) -> Highlight {
+        Highlight::new(tag)
+    }
+}
+
+impl Highlight {
+    pub(crate) fn new(tag: HighlightTag) -> Highlight {
+        Highlight { tag, modifiers: HighlightModifiers::default() }
+    }
+}
+
+impl ops::BitOr<HighlightModifier> for HighlightTag {
+    type Output = Highlight;
+
+    fn bitor(self, rhs: HighlightModifier) -> Highlight {
+        Highlight::new(self) | rhs
+    }
+}
+
+impl ops::BitOrAssign<HighlightModifier> for HighlightModifiers {
+    fn bitor_assign(&mut self, rhs: HighlightModifier) {
+        self.0 |= rhs.mask();
+    }
+}
+
+impl ops::BitOrAssign<HighlightModifier> for Highlight {
+    fn bitor_assign(&mut self, rhs: HighlightModifier) {
+        self.modifiers |= rhs;
+    }
+}
+
+impl ops::BitOr<HighlightModifier> for Highlight {
+    type Output = Highlight;
+
+    fn bitor(mut self, rhs: HighlightModifier) -> Highlight {
+        self |= rhs;
+        self
+    }
+}
+
+impl HighlightModifiers {
+    pub fn iter(self) -> impl Iterator<Item = HighlightModifier> {
+        HighlightModifier::ALL.iter().copied().filter(move |it| self.0 & it.mask() == it.mask())
+    }
+}
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
new file mode 100644
index 000000000..98c030791
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -0,0 +1,133 @@
+use std::fs;
+
+use test_utils::{assert_eq_text, project_dir, read_text};
+
+use crate::{
+    mock_analysis::{single_file, MockAnalysis},
+    FileRange, TextRange,
+};
+
+#[test]
+fn test_highlighting() {
+    let (analysis, file_id) = single_file(
+        r#"
+#[derive(Clone, Debug)]
+struct Foo {
+    pub x: i32,
+    pub y: i32,
+}
+
+fn foo<'a, T>() -> T {
+    foo::<'a, i32>()
+}
+
+macro_rules! def_fn {
+    ($($tt:tt)*) => {$($tt)*}
+}
+
+def_fn! {
+    fn bar() -> u32 {
+        100
+    }
+}
+
+// comment
+fn main() {
+    println!("Hello, {}!", 92);
+
+    let mut vec = Vec::new();
+    if true {
+        let x = 92;
+        vec.push(Foo { x, y: 1 });
+    }
+    unsafe { vec.set_len(0); }
+
+    let mut x = 42;
+    let y = &mut x;
+    let z = &y;
+
+    y;
+}
+
+enum Option<T> {
+    Some(T),
+    None,
+}
+use Option::*;
+
+impl<T> Option<T> {
+    fn and<U>(self, other: Option<U>) -> Option<(T, U)> {
+        match other {
+            None => unimplemented!(),
+            Nope => Nope,
+        }
+    }
+}
+"#
+        .trim(),
+    );
+    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlighting.html");
+    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
+    let expected_html = &read_text(&dst_file);
+    fs::write(dst_file, &actual_html).unwrap();
+    assert_eq_text!(expected_html, actual_html);
+}
+
+#[test]
+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();
+}
+
+fn bar() {
+    let mut hello = "hello";
+}
+"#
+        .trim(),
+    );
+    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/rainbow_highlighting.html");
+    let actual_html = &analysis.highlight_as_html(file_id, true).unwrap();
+    let expected_html = &read_text(&dst_file);
+    fs::write(dst_file, &actual_html).unwrap();
+    assert_eq_text!(expected_html, actual_html);
+}
+
+#[test]
+fn accidentally_quadratic() {
+    let file = project_dir().join("crates/ra_syntax/test_data/accidentally_quadratic");
+    let src = fs::read_to_string(file).unwrap();
+
+    let mut mock = MockAnalysis::new();
+    let file_id = mock.add_file("/main.rs", &src);
+    let host = mock.analysis_host();
+
+    // let t = std::time::Instant::now();
+    let _ = host.analysis().highlight(file_id).unwrap();
+    // eprintln!("elapsed: {:?}", t.elapsed());
+}
+
+#[test]
+fn test_ranges() {
+    let (analysis, file_id) = single_file(
+        r#"
+            #[derive(Clone, Debug)]
+            struct Foo {
+                pub x: i32,
+                pub y: i32,
+            }"#,
+    );
+
+    // The "x"
+    let highlights = &analysis
+        .highlight_range(FileRange { file_id, range: TextRange::offset_len(82.into(), 1.into()) })
+        .unwrap();
+
+    assert_eq!(&highlights[0].highlight.to_string(), "field.declaration");
+}