✨ feat(vscode): 代码阅读能读嵌在一种语言里的另一种语言的代码：语言插件报出是哪几段，宿主交给那种语言的插件只解析这几段、分步、翻成子块并叠着上色，外层翻译插件只问读出来的样子；契约加构建文件的几种块（解析指令、阶段、执行、复制、设置、标签、健康检查、启动）、分作用范围的变量、并成一块的几条语句，引擎排这些块的属性表

vscode/src/codeReader/runtime.ts

@@ -1,5 +1,5 @@
-import type { Tree } from '@vscode/tree-sitter-wasm'
-import type { LanguageAdapter } from './contract'
+import type { Point, Range, Tree } from '@vscode/tree-sitter-wasm'
+import type { LanguageAdapter, SourceRange } from './contract'
 import * as path from 'node:path'
 import { Language, Parser } from '@vscode/tree-sitter-wasm'
 
@@ -8,6 +8,19 @@ export function bundledWasmDir(): string {
   return path.join(__dirname, 'tree-sitter')
 }
 
+/** 源码下标的行列（行从 0 起，列按 UTF-16，同 web-tree-sitter 解析 JS 字符串时的算法）。 */
+function pointAt(source: string, index: number): Point {
+  const lineStart = source.lastIndexOf('\n', index - 1) + 1
+  let row = 0
+  for (let at = source.indexOf('\n'); at !== -1 && at < index; at = source.indexOf('\n', at + 1))
+    row++
+  return { row, column: index - lineStart }
+}
+
+function includedRange(source: string, { startIndex, endIndex }: SourceRange): Range {
+  return { startIndex, endIndex, startPosition: pointAt(source, startIndex), endPosition: pointAt(source, endIndex) }
+}
+
 // 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
 
@@ -27,10 +40,13 @@ export class TreeSitterRuntime {
   /** @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> {
+  /**
+   * 返回的语法树占着 wasm 内存，用完必须 `tree.delete()`。给了 ranges 就只解析源码里的这几段（嵌着的代码，见 EmbeddedCode），
+   * 节点的下标、行列照旧是整份源码的。
+   */
+  async parse(adapter: LanguageAdapter, languageId: string, source: string, ranges?: readonly SourceRange[]): Promise<Tree> {
     const parser = await this.parserFor(adapter.grammarPath(languageId))
-    const tree = parser.parse(source)
+    const tree = parser.parse(source, null, ranges ? { includedRanges: ranges.map(range => includedRange(source, range)) } : undefined)
     if (!tree)
       throw new Error(`tree-sitter 没能解析 ${languageId} 源码`)
     return tree