feat(examples): syntect example for syntax highlighting

Cargo.toml

@@ -25,10 +25,11 @@ indextree = "3.3.0"
 jetscii = "0.4.4"
 memchr = "2.2.1"
 nom = "5.0.0"
-serde = { version = "1.0.97", optional = true, features = ["derive"] }
+serde = { version = "1.0.98", optional = true, features = ["derive"] }
 
 [dev-dependencies]
 lazy_static = "1.3.0"
 pretty_assertions = "0.6.1"
 serde_json = "1.0.40"
 slugify = "0.1.0"
+syntect = "3.2.0"

STATUS.md

@@ -67,4 +67,4 @@ Check out https://orgmode.org/worg/dev/org-syntax.html for more information.
 
 ## Extra
 
-- [ ] Syntax Highlighting
+- [X] Syntax Highlighting

examples/syntect.rs

@@ -0,0 +1,94 @@
+use std::env::args;
+use std::fs;
+use std::io::{Error, Result, Write};
+use syntect::{
+    easy::HighlightLines,
+    highlighting::ThemeSet,
+    html::{styled_line_to_highlighted_html, IncludeBackground},
+    parsing::SyntaxSet,
+};
+
+use orgize::export::{DefaultHtmlHandler, HtmlHandler};
+use orgize::{Element, Org};
+
+pub struct SyntectHtmlHandler {
+    syntax_set: SyntaxSet,
+    theme_set: ThemeSet,
+    default_hanlder: DefaultHtmlHandler,
+}
+
+impl Default for SyntectHtmlHandler {
+    fn default() -> Self {
+        SyntectHtmlHandler {
+            syntax_set: SyntaxSet::load_defaults_newlines(),
+            theme_set: ThemeSet::load_defaults(),
+            default_hanlder: DefaultHtmlHandler,
+        }
+    }
+}
+
+impl SyntectHtmlHandler {
+    fn highlight(&self, language: Option<&str>, content: &str) -> String {
+        let mut highlighter = HighlightLines::new(
+            language
+                .and_then(|lang| self.syntax_set.find_syntax_by_token(lang))
+                .unwrap_or_else(|| self.syntax_set.find_syntax_plain_text()),
+            &self.theme_set.themes["InspiredGitHub"],
+        );
+        let regions = highlighter.highlight(content, &self.syntax_set);
+        styled_line_to_highlighted_html(&regions[..], IncludeBackground::No)
+    }
+}
+
+impl HtmlHandler<Error> for SyntectHtmlHandler {
+    fn start<W: Write>(&mut self, mut w: W, element: &Element<'_>) -> Result<()> {
+        match element {
+            Element::InlineSrc(inline_src) => write!(
+                w,
+                "<code>{}</code>",
+                self.highlight(Some(inline_src.lang), inline_src.body)
+            )?,
+            Element::SourceBlock(block) => {
+                if block.language.is_empty() {
+                    write!(w, "<pre class=\"example\">{}</pre>", block.contents)?;
+                } else {
+                    write!(
+                        w,
+                        "<div class=\"org-src-container\"><pre class=\"src src-{}\">{}</pre></div>",
+                        block.language,
+                        self.highlight(Some(block.language), block.contents)
+                    )?
+                }
+            }
+            Element::FixedWidth { value } => write!(
+                w,
+                "<pre class=\"example\">{}</pre>",
+                self.highlight(None, value)
+            )?,
+            Element::ExampleBlock(block) => write!(
+                w,
+                "<pre class=\"example\">{}</pre>",
+                self.highlight(None, block.contents)
+            )?,
+            _ => self.default_hanlder.start(w, element)?,
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    let args: Vec<_> = args().collect();
+
+    if args.len() < 2 {
+        eprintln!("Usage: {} <org-file>", args[0]);
+    } else {
+        let contents = String::from_utf8(fs::read(&args[1]).unwrap()).unwrap();
+
+        let mut writer = Vec::new();
+        Org::parse(&contents)
+            .html_with_handler(&mut writer, SyntectHtmlHandler::default())
+            .unwrap();
+
+        println!("{}", String::from_utf8(writer).unwrap());
+    }
+}