Add Haskell support

Fixes #36

CHANGELOG.md

@@ -7,6 +7,8 @@ Added a C parser.
 Added a C++ parser. Difftastic prefers the C++ parser for `.h`
 files. Please file a bug if you see issues.
 
+Added a Haskell parser.
+
 Removed legacy regex-based parsing backend.
 
 ### Diffing

README.md

@@ -23,6 +23,7 @@ Difftastic supports the following languages:
 * Elixir
 * Emacs Lisp
 * Go
+* Haskell
 * Java
 * JavaScript (and JSX)
 * JSON

build.rs

@@ -19,7 +19,8 @@ fn build(package_name: &str, package_dir: &str, extra_files: &[&str]) {
         cpp_build
             .include(&dir)
             .cpp(true)
-            .flag("-Wno-unused-parameter");
+            .flag("-Wno-unused-parameter")
+            .flag("-Wno-ignored-qualifiers");
         for file in cpp_files {
             cpp_build.file(dir.join(file));
         }
@@ -58,6 +59,11 @@ fn main() {
         &["scanner.cc"],
     );
     build("tree-sitter-go", "vendor/tree-sitter-go-src", &[]);
+    build(
+        "tree-sitter-haskell",
+        "vendor/tree-sitter-haskell-src",
+        &["scanner.cc"],
+    );
     build("tree-sitter-java", "vendor/tree-sitter-java-src", &[]);
     build(
         "tree-sitter-javascript",

manual/src/introduction.md

@@ -1,7 +1,7 @@
 # Introduction
 
 Difftastic is a diff tool that understands syntax. It currently
-supports 16 languages:
+supports 17 languages:
 
 * C
 * C++
@@ -10,6 +10,7 @@ supports 16 languages:
 * Elixir
 * Emacs Lisp
 * Go
+* Haskell
 * Java
 * JavaScript (and JSX)
 * JSON

manual/src/upstream_parsers.md

@@ -11,6 +11,7 @@ Difftastic uses the following tree-sitter parsers:
 | Elixir          | [ananthakumaran/tree-sitter-elixir](https://github.com/ananthakumaran/tree-sitter-elixir)   |
 | Emacs Lisp      | [wilfred/tree-sitter-elisp](https://github.com/Wilfred/tree-sitter-elisp)                   |
 | Go              | [tree-sitter/tree-sitter-go](https://github.com/tree-sitter/tree-sitter-go)                 |
+| Haskell         | [tree-sitter/tree-sitter-haskell](https://github.com/tree-sitter/tree-sitter-haskell)       |
 | Java            | [tree-sitter/tree-sitter-java](https://github.com/tree-sitter/tree-sitter-java)             |
 | JavaScript, JSX | [tree-sitter/tree-sitter-javascript](https://github.com/tree-sitter/tree-sitter-javascript) |
 | JSON            | [tree-sitter/tree-sitter-json](https://github.com/tree-sitter/tree-sitter-json)             |

src/tree_sitter_parser.rs

@@ -32,6 +32,7 @@ extern "C" {
     fn tree_sitter_elisp() -> Language;
     fn tree_sitter_elixir() -> Language;
     fn tree_sitter_go() -> Language;
+    fn tree_sitter_haskell() -> Language;
     fn tree_sitter_java() -> Language;
     fn tree_sitter_javascript() -> Language;
     fn tree_sitter_json() -> Language;
@@ -106,6 +107,12 @@ pub fn from_extension(extension: &OsStr) -> Option<TreeSitterConfig> {
                 .collect(),
             open_delimiter_tokens: (vec!["{", "[", "("]).into_iter().collect(),
         }),
+        "hs" => Some(TreeSitterConfig {
+            name: "Haskell",
+            language: unsafe { tree_sitter_haskell() },
+            atom_nodes: (vec![]).into_iter().collect(),
+            open_delimiter_tokens: (vec!["[", "("]).into_iter().collect(),
+        }),
         "java" => Some(TreeSitterConfig {
             name: "Java",
             language: unsafe { tree_sitter_java() },