//! Syntax highlighting for Typst source code.
use std::fmt::Write;
use std::ops::Range;
use syntect::highlighting::{Color, FontStyle, Highlighter, Style, Theme};
use syntect::parsing::Scope;
use super::{parse, SyntaxKind, SyntaxNode};
/// Highlight source text into a standalone HTML document.
pub fn highlight_html(text: &str, theme: &Theme) -> String {
let mut buf = String::new();
buf.push_str("\n");
buf.push_str("\n");
buf.push_str("\n");
buf.push_str(" \n");
buf.push_str("\n");
buf.push_str("\n");
buf.push_str(&highlight_pre(text, theme));
buf.push_str("\n\n");
buf.push_str("\n");
buf
}
/// Highlight source text into an HTML pre element.
pub fn highlight_pre(text: &str, theme: &Theme) -> String {
let mut buf = String::new();
buf.push_str("\n");
let root = parse(text);
highlight_themed(&root, theme, |range, style| {
let styled = style != Style::default();
if styled {
buf.push_str("");
}
buf.push_str(&text[range]);
if styled {
buf.push_str("");
}
});
buf.push_str("\n");
buf
}
/// Highlight a syntax node in a theme by calling `f` with ranges and their
/// styles.
pub fn highlight_themed(root: &SyntaxNode, theme: &Theme, mut f: F)
where
F: FnMut(Range, Style),
{
fn process(
mut offset: usize,
node: &SyntaxNode,
scopes: Vec,
highlighter: &Highlighter,
f: &mut F,
) where
F: FnMut(Range, Style),
{
if node.children().len() == 0 {
let range = offset..offset + node.len();
let style = highlighter.style_for_stack(&scopes);
f(range, style);
return;
}
for (i, child) in node.children().enumerate() {
let mut scopes = scopes.clone();
if let Some(category) = Category::determine(child, node, i) {
scopes.push(Scope::new(category.tm_scope()).unwrap())
}
process(offset, child, scopes, highlighter, f);
offset += child.len();
}
}
let highlighter = Highlighter::new(theme);
process(0, root, vec![], &highlighter, &mut f);
}
/// Highlight a syntax node by calling `f` with ranges overlapping `within` and
/// their categories.
pub fn highlight_categories(root: &SyntaxNode, within: Range, mut f: F)
where
F: FnMut(Range, Category),
{
fn process(mut offset: usize, node: &SyntaxNode, range: Range, f: &mut F)
where
F: FnMut(Range, Category),
{
for (i, child) in node.children().enumerate() {
let span = offset..offset + child.len();
if range.start <= span.end && range.end >= span.start {
if let Some(category) = Category::determine(child, node, i) {
f(span, category);
}
process(offset, child, range.clone(), f);
}
offset += child.len();
}
}
process(0, root, within, &mut f)
}
/// The syntax highlighting category of a node.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum Category {
/// A line or block comment.
Comment,
/// A square bracket, parenthesis or brace.
Bracket,
/// Punctuation in code.
Punctuation,
/// An escape sequence.
Escape,
/// An easily typable shortcut to a unicode codepoint.
Shorthand,
/// Symbol notation.
Symbol,
/// A smart quote.
SmartQuote,
/// Strong markup.
Strong,
/// Emphasized markup.
Emph,
/// A hyperlink.
Link,
/// Raw text.
Raw,
/// A label.
Label,
/// A reference.
Ref,
/// A section heading.
Heading,
/// A full item of a list, enumeration or description list.
ListItem,
/// A marker of a list, enumeration, or description list.
ListMarker,
/// A term in a description list.
ListTerm,
/// The delimiters of a math formula.
MathDelimiter,
/// An operator with special meaning in a math formula.
MathOperator,
/// A keyword.
Keyword,
/// A literal defined by a keyword like `none`, `auto` or a boolean.
KeywordLiteral,
/// An operator symbol.
Operator,
/// A numeric literal.
Number,
/// A string literal.
String,
/// A function or method name.
Function,
/// An interpolated variable in markup or math.
Interpolated,
/// A syntax error.
Error,
}
impl Category {
/// Determine the highlighting category of a node given its parent and its
/// index in its siblings.
pub fn determine(
child: &SyntaxNode,
parent: &SyntaxNode,
i: usize,
) -> Option {
match child.kind() {
SyntaxKind::LineComment => Some(Category::Comment),
SyntaxKind::BlockComment => Some(Category::Comment),
SyntaxKind::Space { .. } => None,
SyntaxKind::LeftBrace => Some(Category::Bracket),
SyntaxKind::RightBrace => Some(Category::Bracket),
SyntaxKind::LeftBracket => Some(Category::Bracket),
SyntaxKind::RightBracket => Some(Category::Bracket),
SyntaxKind::LeftParen => Some(Category::Bracket),
SyntaxKind::RightParen => Some(Category::Bracket),
SyntaxKind::Comma => Some(Category::Punctuation),
SyntaxKind::Semicolon => Some(Category::Punctuation),
SyntaxKind::Colon => Some(Category::Punctuation),
SyntaxKind::Star => match parent.kind() {
SyntaxKind::Strong => None,
_ => Some(Category::Operator),
},
SyntaxKind::Underscore => match parent.kind() {
SyntaxKind::Script => Some(Category::MathOperator),
_ => None,
},
SyntaxKind::Dollar => Some(Category::MathDelimiter),
SyntaxKind::Plus => Some(match parent.kind() {
SyntaxKind::EnumItem => Category::ListMarker,
_ => Category::Operator,
}),
SyntaxKind::Minus => Some(match parent.kind() {
SyntaxKind::ListItem => Category::ListMarker,
_ => Category::Operator,
}),
SyntaxKind::Slash => Some(match parent.kind() {
SyntaxKind::DescItem => Category::ListMarker,
SyntaxKind::Frac => Category::MathOperator,
_ => Category::Operator,
}),
SyntaxKind::Hat => Some(Category::MathOperator),
SyntaxKind::Amp => Some(Category::MathOperator),
SyntaxKind::Dot => Some(Category::Punctuation),
SyntaxKind::Eq => match parent.kind() {
SyntaxKind::Heading => None,
_ => Some(Category::Operator),
},
SyntaxKind::EqEq => Some(Category::Operator),
SyntaxKind::ExclEq => Some(Category::Operator),
SyntaxKind::Lt => Some(Category::Operator),
SyntaxKind::LtEq => Some(Category::Operator),
SyntaxKind::Gt => Some(Category::Operator),
SyntaxKind::GtEq => Some(Category::Operator),
SyntaxKind::PlusEq => Some(Category::Operator),
SyntaxKind::HyphEq => Some(Category::Operator),
SyntaxKind::StarEq => Some(Category::Operator),
SyntaxKind::SlashEq => Some(Category::Operator),
SyntaxKind::Dots => Some(Category::Operator),
SyntaxKind::Arrow => Some(Category::Operator),
SyntaxKind::Not => Some(Category::Keyword),
SyntaxKind::And => Some(Category::Keyword),
SyntaxKind::Or => Some(Category::Keyword),
SyntaxKind::None => Some(Category::KeywordLiteral),
SyntaxKind::Auto => Some(Category::KeywordLiteral),
SyntaxKind::Let => Some(Category::Keyword),
SyntaxKind::Set => Some(Category::Keyword),
SyntaxKind::Show => Some(Category::Keyword),
SyntaxKind::If => Some(Category::Keyword),
SyntaxKind::Else => Some(Category::Keyword),
SyntaxKind::For => Some(Category::Keyword),
SyntaxKind::In => Some(Category::Keyword),
SyntaxKind::While => Some(Category::Keyword),
SyntaxKind::Break => Some(Category::Keyword),
SyntaxKind::Continue => Some(Category::Keyword),
SyntaxKind::Return => Some(Category::Keyword),
SyntaxKind::Import => Some(Category::Keyword),
SyntaxKind::Include => Some(Category::Keyword),
SyntaxKind::From => Some(Category::Keyword),
SyntaxKind::Markup { .. } => match parent.kind() {
SyntaxKind::DescItem
if parent
.children()
.take_while(|child| child.kind() != &SyntaxKind::Colon)
.find(|c| matches!(c.kind(), SyntaxKind::Markup { .. }))
.map_or(false, |ident| std::ptr::eq(ident, child)) =>
{
Some(Category::ListTerm)
}
_ => None,
},
SyntaxKind::Text(_) => None,
SyntaxKind::Linebreak => Some(Category::Escape),
SyntaxKind::Escape(_) => Some(Category::Escape),
SyntaxKind::Shorthand(_) => Some(Category::Shorthand),
SyntaxKind::Symbol(_) => Some(Category::Symbol),
SyntaxKind::SmartQuote { .. } => Some(Category::SmartQuote),
SyntaxKind::Strong => Some(Category::Strong),
SyntaxKind::Emph => Some(Category::Emph),
SyntaxKind::Raw(_) => Some(Category::Raw),
SyntaxKind::Link(_) => Some(Category::Link),
SyntaxKind::Label(_) => Some(Category::Label),
SyntaxKind::Ref(_) => Some(Category::Ref),
SyntaxKind::Heading => Some(Category::Heading),
SyntaxKind::ListItem => Some(Category::ListItem),
SyntaxKind::EnumItem => Some(Category::ListItem),
SyntaxKind::EnumNumbering(_) => Some(Category::ListMarker),
SyntaxKind::DescItem => Some(Category::ListItem),
SyntaxKind::Math => None,
SyntaxKind::Atom(_) => None,
SyntaxKind::Script => None,
SyntaxKind::Frac => None,
SyntaxKind::AlignPoint => None,
SyntaxKind::Ident(_) => match parent.kind() {
SyntaxKind::Markup { .. }
| SyntaxKind::Math
| SyntaxKind::Script
| SyntaxKind::Frac => Some(Category::Interpolated),
SyntaxKind::FuncCall => Some(Category::Function),
SyntaxKind::MethodCall if i > 0 => Some(Category::Function),
SyntaxKind::Closure if i == 0 => Some(Category::Function),
SyntaxKind::SetRule => Some(Category::Function),
SyntaxKind::ShowRule
if parent
.children()
.rev()
.skip_while(|child| child.kind() != &SyntaxKind::Colon)
.find(|c| matches!(c.kind(), SyntaxKind::Ident(_)))
.map_or(false, |ident| std::ptr::eq(ident, child)) =>
{
Some(Category::Function)
}
_ => None,
},
SyntaxKind::Bool(_) => Some(Category::KeywordLiteral),
SyntaxKind::Int(_) => Some(Category::Number),
SyntaxKind::Float(_) => Some(Category::Number),
SyntaxKind::Numeric(_, _) => Some(Category::Number),
SyntaxKind::Str(_) => Some(Category::String),
SyntaxKind::CodeBlock => None,
SyntaxKind::ContentBlock => None,
SyntaxKind::Parenthesized => None,
SyntaxKind::Array => None,
SyntaxKind::Dict => None,
SyntaxKind::Named => None,
SyntaxKind::Keyed => None,
SyntaxKind::Unary => None,
SyntaxKind::Binary => None,
SyntaxKind::FieldAccess => None,
SyntaxKind::FuncCall => None,
SyntaxKind::MethodCall => None,
SyntaxKind::Args => None,
SyntaxKind::Spread => None,
SyntaxKind::Closure => None,
SyntaxKind::Params => None,
SyntaxKind::LetBinding => None,
SyntaxKind::SetRule => None,
SyntaxKind::ShowRule => None,
SyntaxKind::Conditional => None,
SyntaxKind::WhileLoop => None,
SyntaxKind::ForLoop => None,
SyntaxKind::ForPattern => None,
SyntaxKind::ModuleImport => None,
SyntaxKind::ImportItems => None,
SyntaxKind::ModuleInclude => None,
SyntaxKind::LoopBreak => None,
SyntaxKind::LoopContinue => None,
SyntaxKind::FuncReturn => None,
SyntaxKind::Error(_, _) => Some(Category::Error),
}
}
/// Return the TextMate grammar scope for the given highlighting category.
pub fn tm_scope(&self) -> &'static str {
match self {
Self::Comment => "comment.typst",
Self::Bracket => "punctuation.definition.bracket.typst",
Self::Punctuation => "punctuation.typst",
Self::Escape => "constant.character.escape.typst",
Self::Shorthand => "constant.character.shorthand.typst",
Self::Symbol => "constant.symbol.typst",
Self::SmartQuote => "constant.character.quote.typst",
Self::Strong => "markup.bold.typst",
Self::Emph => "markup.italic.typst",
Self::Link => "markup.underline.link.typst",
Self::Raw => "markup.raw.typst",
Self::MathDelimiter => "punctuation.definition.math.typst",
Self::MathOperator => "keyword.operator.math.typst",
Self::Heading => "markup.heading.typst",
Self::ListItem => "markup.list.typst",
Self::ListMarker => "punctuation.definition.list.typst",
Self::ListTerm => "markup.list.term.typst",
Self::Label => "entity.name.label.typst",
Self::Ref => "markup.other.reference.typst",
Self::Keyword => "keyword.typst",
Self::Operator => "keyword.operator.typst",
Self::KeywordLiteral => "constant.language.typst",
Self::Number => "constant.numeric.typst",
Self::String => "string.quoted.double.typst",
Self::Function => "entity.name.function.typst",
Self::Interpolated => "meta.interpolation.typst",
Self::Error => "invalid.typst",
}
}
}
#[cfg(test)]
mod tests {
use super::super::Source;
use super::*;
#[test]
fn test_highlighting() {
use Category::*;
#[track_caller]
fn test(text: &str, goal: &[(Range, Category)]) {
let mut vec = vec![];
let source = Source::detached(text);
let full = 0..text.len();
highlight_categories(source.root(), full, &mut |range, category| {
vec.push((range, category));
});
assert_eq!(vec, goal);
}
test("= *AB*", &[(0..6, Heading), (2..6, Strong)]);
test(
"#f(x + 1)",
&[
(0..2, Function),
(2..3, Bracket),
(5..6, Operator),
(7..8, Number),
(8..9, Bracket),
],
);
test(
"#let f(x) = x",
&[
(0..4, Keyword),
(5..6, Function),
(6..7, Bracket),
(8..9, Bracket),
(10..11, Operator),
],
);
}
}