Merge #3335

3335: Refactor highlighting a bit r=matklad a=matklad

bors r+

Co-authored-by: Aleksey Kladov <[email protected]>

3 files changed, 267 insertions, 43 deletions

diff --git a/crates/ra_ide/src/syntax_highlighting/highlight.rs b/crates/ra_ide/src/syntax_highlighting/highlight.rs
new file mode 100644
index 000000000..383c74c98
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/highlight.rs
@@ -0,0 +1,163 @@
+//! 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 {
+    Field,
+    Function,
+    Module,
+    Constant,
+    Macro,
+    Variable,
+
+    Type,
+    TypeSelf,
+    TypeParam,
+    TypeLifetime,
+
+    LiteralByte,
+    LiteralNumeric,
+    LiteralChar,
+
+    Comment,
+    LiteralString,
+    Attribute,
+
+    Keyword,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[repr(u8)]
+pub enum HighlightModifier {
+    Mutable = 0,
+    Unsafe,
+    /// Used with keywords like `if` and `break`.
+    Control,
+    Builtin,
+}
+
+impl HighlightTag {
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightTag::Field => "field",
+            HighlightTag::Function => "function",
+            HighlightTag::Module => "module",
+            HighlightTag::Constant => "constant",
+            HighlightTag::Macro => "macro",
+            HighlightTag::Variable => "variable",
+            HighlightTag::Type => "type",
+            HighlightTag::TypeSelf => "type.self",
+            HighlightTag::TypeParam => "type.param",
+            HighlightTag::TypeLifetime => "type.lifetime",
+            HighlightTag::LiteralByte => "literal.byte",
+            HighlightTag::LiteralNumeric => "literal.numeric",
+            HighlightTag::LiteralChar => "literal.char",
+            HighlightTag::Comment => "comment",
+            HighlightTag::LiteralString => "string",
+            HighlightTag::Attribute => "attribute",
+            HighlightTag::Keyword => "keyword",
+        }
+    }
+}
+
+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::Mutable,
+        HighlightModifier::Unsafe,
+        HighlightModifier::Control,
+        HighlightModifier::Builtin,
+    ];
+
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightModifier::Mutable => "mutable",
+            HighlightModifier::Unsafe => "unsafe",
+            HighlightModifier::Control => "control",
+            HighlightModifier::Builtin => "builtin",
+        }
+    }
+
+    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/highlight_tag.rs b/crates/ra_ide/src/syntax_highlighting/highlight_tag.rs
deleted file mode 100644
index af1ac07b3..000000000
--- a/crates/ra_ide/src/syntax_highlighting/highlight_tag.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-//! Defines token tags we use for syntax highlighting.
-//! A tag is not unlike a CSS class.
-
-use std::fmt;
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub struct HighlightTag(&'static str);
-
-impl fmt::Display for HighlightTag {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(self.0, f)
-    }
-}
-
-#[rustfmt::skip]
-impl HighlightTag {
-    pub const FIELD: HighlightTag              = HighlightTag("field");
-    pub const FUNCTION: HighlightTag           = HighlightTag("function");
-    pub const MODULE: HighlightTag             = HighlightTag("module");
-    pub const CONSTANT: HighlightTag           = HighlightTag("constant");
-    pub const MACRO: HighlightTag              = HighlightTag("macro");
-
-    pub const VARIABLE: HighlightTag           = HighlightTag("variable");
-    pub const VARIABLE_MUT: HighlightTag       = HighlightTag("variable.mut");
-
-    pub const TYPE: HighlightTag               = HighlightTag("type");
-    pub const TYPE_BUILTIN: HighlightTag       = HighlightTag("type.builtin");
-    pub const TYPE_SELF: HighlightTag          = HighlightTag("type.self");
-    pub const TYPE_PARAM: HighlightTag         = HighlightTag("type.param");
-    pub const TYPE_LIFETIME: HighlightTag      = HighlightTag("type.lifetime");
-
-    pub const LITERAL_BYTE: HighlightTag       = HighlightTag("literal.byte");
-    pub const LITERAL_NUMERIC: HighlightTag    = HighlightTag("literal.numeric");
-    pub const LITERAL_CHAR: HighlightTag       = HighlightTag("literal.char");
-
-    pub const LITERAL_COMMENT: HighlightTag    = HighlightTag("comment");
-    pub const LITERAL_STRING: HighlightTag     = HighlightTag("string");
-    pub const LITERAL_ATTRIBUTE: HighlightTag  = HighlightTag("attribute");
-
-    pub const KEYWORD: HighlightTag            = HighlightTag("keyword");
-    pub const KEYWORD_UNSAFE: HighlightTag     = HighlightTag("keyword.unsafe");
-    pub const KEYWORD_CONTROL: HighlightTag    = HighlightTag("keyword.control");
-}
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..210d9a57b
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/html.rs
@@ -0,0 +1,104 @@
+//! 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; }
+
+.comment            { color: #7F9F7F; }
+.string             { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.type.builtin       { color: #8CD0D3; }
+.type.param         { color: #20999D; }
+.attribute          { color: #94BFF3; }
+.literal            { color: #BFEBBF; }
+.literal.numeric    { color: #6A8759; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.variable           { color: #DCDCCC; }
+.variable.mut       { color: #DCDCCC; text-decoration: underline; }
+
+.keyword            { color: #F0DFAF; }
+.keyword.unsafe     { color: #DFAF8F; }
+.keyword.control    { color: #F0DFAF; font-weight: bold; }
+</style>
+";