✨ feat(vscode): 代码阅读的解析与模板直译核心

vscode/src/codeReader/runtime.ts

@@ -0,0 +1,50 @@
+import type { Tree } from '@vscode/tree-sitter-wasm'
+import type { LanguageAdapter } from './contract'
+import * as path from 'node:path'
+import { Language, Parser } from '@vscode/tree-sitter-wasm'
+
+/** 打进扩展包里的 wasm 目录：dist/index.cjs 旁边的 dist/tree-sitter（esbuild 构建时复制）。只在打包产物里成立。 */
+export function bundledWasmDir(): string {
+  return path.join(__dirname, 'tree-sitter')
+}
+
+// web-tree-sitter 的运行时是进程级单例：Parser.init 只能有效调用一次，后来的 wasm 目录不再生效
+let runtimeReady: Promise<void> | undefined
+
+function initRuntime(wasmDir: string): Promise<void> {
+  runtimeReady ??= Parser.init({ locateFile: (file: string) => path.join(wasmDir, file) })
+    .catch((err: unknown) => {
+      runtimeReady = undefined
+      throw err
+    })
+  return runtimeReady
+}
+
+/** 解析运行时：初始化一次 web-tree-sitter，语法包按 wasm 路径懒加载并缓存。 */
+export class TreeSitterRuntime {
+  private readonly parsers = new Map<string, Promise<Parser>>()
+
+  /** @param wasmDir 放 tree-sitter.wasm 的目录 */
+  constructor(private readonly wasmDir: string) {}
+
+  /** 返回的语法树占着 wasm 内存，用完必须 `tree.delete()`。 */
+  async parse(adapter: LanguageAdapter, languageId: string, source: string): Promise<Tree> {
+    const parser = await this.parserFor(adapter.grammarPath(languageId))
+    const tree = parser.parse(source)
+    if (!tree)
+      throw new Error(`tree-sitter 没能解析 ${languageId} 源码`)
+    return tree
+  }
+
+  private parserFor(grammarPath: string): Promise<Parser> {
+    let parser = this.parsers.get(grammarPath)
+    if (!parser) {
+      parser = initRuntime(this.wasmDir)
+        .then(() => Language.load(grammarPath))
+        .then(language => new Parser().setLanguage(language))
+      parser.catch(() => this.parsers.delete(grammarPath))
+      this.parsers.set(grammarPath, parser)
+    }
+    return parser
+  }
+}