feat: add syntax highlighting for 9 additional languages

- Cargo.toml: Add tree-sitter grammars for Nix, Python, JavaScript,
  TypeScript, Go, C, CSS, HTML, YAML. Upgrade tree-sitter-highlight
  to 0.26 for language version 15 compatibility.

- src/highlight.rs: Add Language enum variants and get_config()
  match arms for all new languages. Update render() callback for
  0.26 API (writes attributes to buffer). Add tests for Nix and
  Python highlighting.

TOML excluded due to incompatible API (tree-sitter 0.20 vs 0.26).

Cargo.lock

@@ -511,12 +511,21 @@ dependencies = [
  "maud",
  "pulldown-cmark",
  "serde",
- "thiserror 2.0.18",
+ "thiserror",
  "toml 0.8.23",
  "tree-sitter-bash",
+ "tree-sitter-c",
+ "tree-sitter-css",
+ "tree-sitter-go",
  "tree-sitter-highlight",
+ "tree-sitter-html",
+ "tree-sitter-javascript",
  "tree-sitter-json",
+ "tree-sitter-nix",
+ "tree-sitter-python",
  "tree-sitter-rust",
+ "tree-sitter-typescript",
+ "tree-sitter-yaml",
  "walkdir",
 ]
 
@@ -926,6 +935,7 @@ version = "1.0.149"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "83fc039473c5595ace860d8c4fafa220ff474b3fc6bfdb4293327f1a37e94d86"
 dependencies = [
+ "indexmap",
  "itoa",
  "memchr",
  "serde",
@@ -1009,33 +1019,13 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
-[[package]]
-name = "thiserror"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
-dependencies = [
- "thiserror-impl 1.0.69",
-]
-
 [[package]]
 name = "thiserror"
 version = "2.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4288b5bcbc7920c07a1149a35cf9590a2aa808e0bc1eafaade0b80947865fbc4"
 dependencies = [
- "thiserror-impl 2.0.18",
+ "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.114",
 ]
 
 [[package]]
@@ -1116,13 +1106,14 @@ checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
 
 [[package]]
 name = "tree-sitter"
-version = "0.24.7"
+version = "0.26.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5387dffa7ffc7d2dae12b50c6f7aab8ff79d6210147c6613561fc3d474c6f75"
+checksum = "974d205cc395652cfa8b37daa053fe56eebd429acf8dc055503fee648dae981e"
 dependencies = [
  "cc",
  "regex",
  "regex-syntax",
+ "serde_json",
  "streaming-iterator",
  "tree-sitter-language",
 ]
@@ -1138,18 +1129,67 @@ dependencies = [
 ]
 
 [[package]]
-name = "tree-sitter-highlight"
+name = "tree-sitter-c"
-version = "0.24.7"
+version = "0.24.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6411813e4a9ebc87d391b98b0f3ce65d5361cd80c54de8651d8b85b555ea5d95"
+checksum = "1a3aad8f0129083a59fe8596157552d2bb7148c492d44c21558d68ca1c722707"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-css"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5cbc5e18f29a2c6d6435891f42569525cf95435a3e01c2f1947abcde178686f"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-go"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8560a4d2f835cc0d4d2c2e03cbd0dde2f6114b43bc491164238d333e28b16ea"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-highlight"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb0636662a03005d9289649e0b4a89ff37b75df5033e8d4a16398740ae6496d2"
 dependencies = [
- "lazy_static",
  "regex",
  "streaming-iterator",
- "thiserror 1.0.69",
+ "thiserror",
  "tree-sitter",
 ]
 
+[[package]]
+name = "tree-sitter-html"
+version = "0.23.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "261b708e5d92061ede329babaaa427b819329a9d427a1d710abb0f67bbef63ee"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-javascript"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68204f2abc0627a90bdf06e605f5c470aa26fdcb2081ea553a04bdad756693f5"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "tree-sitter-json"
 version = "0.24.8"
@@ -1166,6 +1206,26 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ae62f7eae5eb549c71b76658648b72cc6111f2d87d24a1e31fa907f4943e3ce"
 
+[[package]]
+name = "tree-sitter-nix"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4952a9733f3a98f6683a0ccd1035d84ab7a52f7e84eeed58548d86765ad92de3"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-python"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6bf85fd39652e740bf60f46f4cda9492c3a9ad75880575bf14960f775cb74a1c"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "tree-sitter-rust"
 version = "0.23.3"
@@ -1176,6 +1236,26 @@ dependencies = [
  "tree-sitter-language",
 ]
 
+[[package]]
+name = "tree-sitter-typescript"
+version = "0.23.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c5f76ed8d947a75cc446d5fccd8b602ebf0cde64ccf2ffa434d873d7a575eff"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-yaml"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53c223db85f05e34794f065454843b0668ebc15d240ada63e2b5939f43ce7c97"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "unicase"
 version = "2.9.0"

Cargo.toml

@@ -13,10 +13,19 @@ thiserror      = "2"
 walkdir        = "2"
 
 # Syntax highlighting
-tree-sitter-bash      = "0.23"
+tree-sitter-bash       = "0.23"
-tree-sitter-highlight = "0.24"
+tree-sitter-c          = "0.24"
-tree-sitter-json      = "0.24"
+tree-sitter-css        = "0.25"
-tree-sitter-rust      = "0.23"
+tree-sitter-go         = "0.25"
+tree-sitter-highlight  = "0.26"
+tree-sitter-html       = "0.23"
+tree-sitter-javascript = "0.25"
+tree-sitter-json       = "0.24"
+tree-sitter-nix        = "0.3"
+tree-sitter-python     = "0.25"
+tree-sitter-rust       = "0.23"
+tree-sitter-typescript = "0.23"
+tree-sitter-yaml       = "0.7"
 
 # CSS processing
 lightningcss = "1.0.0-alpha.70"

src/highlight.rs

@@ -56,18 +56,36 @@ const HTML_ATTRS: &[&[u8]] = &[
 /// Supported languages for syntax highlighting.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Language {
-    Rust,
     Bash,
+    C,
+    Css,
+    Go,
+    Html,
+    JavaScript,
     Json,
+    Nix,
+    Python,
+    Rust,
+    TypeScript,
+    Yaml,
 }
 
 impl Language {
     /// Parse a language identifier from a code fence.
     pub fn from_fence(lang: &str) -> Option<Self> {
         match lang.to_lowercase().as_str() {
-            "rust" | "rs" => Some(Language::Rust),
             "bash" | "sh" | "shell" | "zsh" => Some(Language::Bash),
+            "c" => Some(Language::C),
+            "css" => Some(Language::Css),
+            "go" | "golang" => Some(Language::Go),
+            "html" => Some(Language::Html),
+            "javascript" | "js" => Some(Language::JavaScript),
             "json" => Some(Language::Json),
+            "nix" => Some(Language::Nix),
+            "python" | "py" => Some(Language::Python),
+            "rust" | "rs" => Some(Language::Rust),
+            "typescript" | "ts" | "tsx" => Some(Language::TypeScript),
+            "yaml" | "yml" => Some(Language::Yaml),
             _ => None,
         }
     }
@@ -76,21 +94,66 @@ impl Language {
 /// Get highlight configuration for a language.
 fn get_config(lang: Language) -> HighlightConfiguration {
     let (language, name, highlights) = match lang {
-        Language::Rust => (
-            tree_sitter_rust::LANGUAGE.into(),
-            "rust",
-            tree_sitter_rust::HIGHLIGHTS_QUERY,
-        ),
         Language::Bash => (
             tree_sitter_bash::LANGUAGE.into(),
             "bash",
             tree_sitter_bash::HIGHLIGHT_QUERY,
         ),
+        Language::C => (
+            tree_sitter_c::LANGUAGE.into(),
+            "c",
+            tree_sitter_c::HIGHLIGHT_QUERY,
+        ),
+        Language::Css => (
+            tree_sitter_css::LANGUAGE.into(),
+            "css",
+            tree_sitter_css::HIGHLIGHTS_QUERY,
+        ),
+        Language::Go => (
+            tree_sitter_go::LANGUAGE.into(),
+            "go",
+            tree_sitter_go::HIGHLIGHTS_QUERY,
+        ),
+        Language::Html => (
+            tree_sitter_html::LANGUAGE.into(),
+            "html",
+            tree_sitter_html::HIGHLIGHTS_QUERY,
+        ),
+        Language::JavaScript => (
+            tree_sitter_javascript::LANGUAGE.into(),
+            "javascript",
+            tree_sitter_javascript::HIGHLIGHT_QUERY,
+        ),
         Language::Json => (
             tree_sitter_json::LANGUAGE.into(),
             "json",
             tree_sitter_json::HIGHLIGHTS_QUERY,
         ),
+        Language::Nix => (
+            tree_sitter_nix::LANGUAGE.into(),
+            "nix",
+            tree_sitter_nix::HIGHLIGHTS_QUERY,
+        ),
+        Language::Python => (
+            tree_sitter_python::LANGUAGE.into(),
+            "python",
+            tree_sitter_python::HIGHLIGHTS_QUERY,
+        ),
+        Language::Rust => (
+            tree_sitter_rust::LANGUAGE.into(),
+            "rust",
+            tree_sitter_rust::HIGHLIGHTS_QUERY,
+        ),
+        Language::TypeScript => (
+            tree_sitter_typescript::LANGUAGE_TYPESCRIPT.into(),
+            "typescript",
+            tree_sitter_typescript::HIGHLIGHTS_QUERY,
+        ),
+        Language::Yaml => (
+            tree_sitter_yaml::LANGUAGE.into(),
+            "yaml",
+            tree_sitter_yaml::HIGHLIGHTS_QUERY,
+        ),
     };
 
     let mut config = HighlightConfiguration::new(language, name, highlights, "", "")
@@ -111,8 +174,9 @@ pub fn highlight_code(lang: Language, source: &str) -> String {
     };
 
     let mut renderer = HtmlRenderer::new();
-    let result = renderer.render(highlights, source.as_bytes(), &|highlight| {
+    let result = renderer.render(highlights, source.as_bytes(), &|highlight, buf| {
-        HTML_ATTRS.get(highlight.0).copied().unwrap_or(b"<span>")
+        let attrs = HTML_ATTRS.get(highlight.0).copied().unwrap_or(b"");
+        buf.extend_from_slice(attrs);
     });
 
     match result {
@@ -139,6 +203,27 @@ mod tests {
         assert_eq!(Language::from_fence("bash"), Some(Language::Bash));
         assert_eq!(Language::from_fence("sh"), Some(Language::Bash));
         assert_eq!(Language::from_fence("json"), Some(Language::Json));
+        assert_eq!(Language::from_fence("nix"), Some(Language::Nix));
+        assert_eq!(Language::from_fence("python"), Some(Language::Python));
+        assert_eq!(Language::from_fence("py"), Some(Language::Python));
+        assert_eq!(
+            Language::from_fence("javascript"),
+            Some(Language::JavaScript)
+        );
+        assert_eq!(Language::from_fence("js"), Some(Language::JavaScript));
+        assert_eq!(
+            Language::from_fence("typescript"),
+            Some(Language::TypeScript)
+        );
+        assert_eq!(Language::from_fence("ts"), Some(Language::TypeScript));
+        assert_eq!(Language::from_fence("tsx"), Some(Language::TypeScript));
+        assert_eq!(Language::from_fence("go"), Some(Language::Go));
+        assert_eq!(Language::from_fence("golang"), Some(Language::Go));
+        assert_eq!(Language::from_fence("c"), Some(Language::C));
+        assert_eq!(Language::from_fence("yaml"), Some(Language::Yaml));
+        assert_eq!(Language::from_fence("yml"), Some(Language::Yaml));
+        assert_eq!(Language::from_fence("css"), Some(Language::Css));
+        assert_eq!(Language::from_fence("html"), Some(Language::Html));
         assert_eq!(Language::from_fence("unknown"), None);
     }
 
@@ -147,11 +232,8 @@ mod tests {
         let code = "fn main() { println!(\"hello\"); }";
         let html = highlight_code(Language::Rust, code);
 
-        // Should contain span elements with highlight classes
         assert!(html.contains("class=\"hl-"));
-        // Should contain the keyword "fn"
         assert!(html.contains("fn"));
-        // Should contain the string
         assert!(html.contains("hello"));
     }
 
@@ -164,6 +246,24 @@ mod tests {
         assert!(html.contains("echo"));
     }
 
+    #[test]
+    fn test_highlight_nix_code() {
+        let code = "{ pkgs, ... }: { environment.systemPackages = [ pkgs.vim ]; }";
+        let html = highlight_code(Language::Nix, code);
+
+        assert!(html.contains("class=\"hl-"));
+        assert!(html.contains("pkgs"));
+    }
+
+    #[test]
+    fn test_highlight_python_code() {
+        let code = "def hello():\n    print(\"world\")";
+        let html = highlight_code(Language::Python, code);
+
+        assert!(html.contains("class=\"hl-"));
+        assert!(html.contains("def"));
+    }
+
     #[test]
     fn test_html_escape_fallback() {
         let escaped = html_escape("<script>alert('xss')</script>");