Write tree_sitter/parser.h file in generate command

cli/src/generate/mod.rs

@@ -40,7 +40,9 @@ pub fn generate_parser_in_directory(
         let (language_name, c_code) =
             generate_parser_for_grammar_with_opts(&grammar_json, minimize, state_ids_to_log)?;
         let repo_src_path = repo_path.join("src");
+        let repo_header_path = repo_src_path.join("tree_sitter");
         fs::create_dir_all(&repo_src_path)?;
+        fs::create_dir_all(&repo_header_path)?;
         fs::write(&repo_src_path.join("parser.c"), c_code)
             .map_err(|e| format!("Failed to write parser.c: {}", e))?;
         ensure_file(&repo_src_path.join("binding.cc"), || {
@@ -52,6 +54,9 @@ pub fn generate_parser_in_directory(
         ensure_file(&repo_path.join("index.js"), || {
             npm_files::index_js(&language_name)
         })?;
+        ensure_file(&repo_header_path.join("parser.h"), || {
+            include_str!("../../../lib/include/tree_sitter/parser.h")
+        })?;
     }
     properties::generate_property_sheets(repo_path)?;
     Ok(())
@@ -96,7 +101,10 @@ fn load_grammar_file(grammar_path: &PathBuf) -> Result<String> {
     match grammar_path.extension().and_then(|e| e.to_str()) {
         Some("js") => Ok(load_js_grammar_file(grammar_path)?),
         Some("json") => Ok(fs::read_to_string(grammar_path)?),
-        _ => Err(Error(format!("Unknown grammar file extension: {:?}", grammar_path))),
+        _ => Err(Error(format!(
+            "Unknown grammar file extension: {:?}",
+            grammar_path
+        ))),
     }
 }
 
@@ -129,10 +137,10 @@ fn load_js_grammar_file(grammar_path: &PathBuf) -> Result<String> {
     Ok(String::from_utf8(output.stdout).expect("Got invalid UTF8 from node"))
 }
 
-fn ensure_file(path: &PathBuf, f: impl Fn() -> String) -> Result<()> {
+fn ensure_file<T: AsRef<[u8]>>(path: &PathBuf, f: impl Fn() -> T) -> Result<()> {
     if path.exists() {
         Ok(())
     } else {
-        fs::write(path, f()).map_err(|e| Error(format!("Failed to write file {:?}: {}", path, e)))
+        fs::write(path, f().as_ref()).map_err(|e| Error(format!("Failed to write file {:?}: {}", path, e)))
     }
 }