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use syntect::highlighting::Theme;
use syntect::parsing::SyntaxSet;
use syntect::util::as_24_bit_terminal_escaped;
use syntect::{easy::HighlightLines, parsing::SyntaxReference};
/// Comms from https://github.com/jonschlinkert/sublime-monokai-extended/tree/0ca4e75291515c4d47e2d455e598e03e0dc53745
const THEME: &[u8] = include_bytes!("../../assets/theme.yaml");
/// Comes from https://github.com/sharkdp/bat/raw/5e77ca37e89c873e4490b42ff556370dc5c6ba4f/assets/syntaxes.bin
const SYNTAXES: &[u8] = include_bytes!("../../assets/syntaxes.bin");
pub struct MarkdownRender {
syntax_set: SyntaxSet,
theme: Theme,
md_syntax: SyntaxReference,
txt_syntax: SyntaxReference,
code_syntax: SyntaxReference,
line_type: LineType,
}
impl MarkdownRender {
pub fn new() -> Self {
let syntax_set: SyntaxSet =
bincode::deserialize_from(SYNTAXES).expect("invalid syntaxes.bin");
let theme: Theme = serde_yaml::from_slice(THEME).unwrap();
let md_syntax = syntax_set.find_syntax_by_extension("md").unwrap().clone();
let txt_syntax = syntax_set.find_syntax_by_extension("txt").unwrap().clone();
let code_syntax = txt_syntax.clone();
let line_type = LineType::Normal;
Self {
syntax_set,
theme,
md_syntax,
code_syntax,
txt_syntax,
line_type,
}
}
pub fn render(&mut self, src: &str) -> String {
src.split('\n')
.map(|line| self.render_line(line).unwrap_or_else(|| line.to_string()))
.collect::<Vec<String>>()
.join("\n")
}
pub fn render_line(&mut self, line: &str) -> Option<String> {
if let Some(lang) = detect_code_block(line) {
match self.line_type {
LineType::Normal | LineType::CodeEnd => {
self.line_type = LineType::CodeBegin;
self.code_syntax = if lang.is_empty() {
self.txt_syntax.clone()
} else {
self.find_syntax(&lang)
.cloned()
.unwrap_or_else(|| self.txt_syntax.clone())
};
}
LineType::CodeBegin | LineType::CodeInner => {
self.line_type = LineType::CodeEnd;
self.code_syntax = self.txt_syntax.clone();
}
}
self.render_line_inner(line, &self.md_syntax)
} else {
match self.line_type {
LineType::Normal => self.render_line_inner(line, &self.md_syntax),
LineType::CodeEnd => {
self.line_type = LineType::Normal;
self.render_line_inner(line, &self.md_syntax)
}
LineType::CodeBegin => {
self.line_type = LineType::CodeInner;
self.render_line_inner(line, &self.code_syntax)
}
LineType::CodeInner => self.render_line_inner(line, &self.code_syntax),
}
}
}
pub fn render_line_stateless(&self, line: &str) -> String {
let output = if detect_code_block(line).is_some() {
self.render_line_inner(line, &self.md_syntax)
} else {
match self.line_type {
LineType::Normal | LineType::CodeEnd => {
self.render_line_inner(line, &self.md_syntax)
}
_ => self.render_line_inner(line, &self.code_syntax),
}
};
output.unwrap_or_else(|| line.to_string())
}
fn render_line_inner(&self, line: &str, syntax: &SyntaxReference) -> Option<String> {
let mut highlighter = HighlightLines::new(syntax, &self.theme);
let ranges = highlighter.highlight_line(line, &self.syntax_set).ok()?;
Some(as_24_bit_terminal_escaped(&ranges[..], false))
}
fn find_syntax(&self, lang: &str) -> Option<&SyntaxReference> {
self.syntax_set
.find_syntax_by_token(lang)
.or_else(|| self.syntax_set.find_syntax_by_extension(lang))
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum LineType {
Normal,
CodeBegin,
CodeInner,
CodeEnd,
}
fn detect_code_block(line: &str) -> Option<String> {
if !line.starts_with("```") {
return None;
}
let lang = line
.chars()
.skip(3)
.take_while(|v| v.is_alphanumeric())
.collect();
Some(lang)
}
#[test]
fn feature() {
let syntax_set: SyntaxSet = bincode::deserialize_from(SYNTAXES).expect("invalid syntaxes.bin");
assert!(syntax_set.find_syntax_by_extension("md").is_some());
}
|
