⚡ perf(vscode): 代码阅读预览发给页面的块只记相对位置：块在源码里占的地方记成离前一块多远、自己多长，块里名字的下标从块的开头算，页面从文件开头累加回文件里的位置、和扩展端打交道的地方都在一处换算；靠前改了代码，后面内容没变的块发过去一模一样，扩展端自己的块和发给页面的块分成两种类型

vscode/src/codeReader/diff/previewDiff.ts

@@ -1,12 +1,15 @@
 import type { FileAttribute } from '../attributes'
 import type { BlockView } from '../blockView'
+import type { PageCard } from '../editor/messages'
 import type { ChangedBlock, DiffStats, RemovedBlock } from './blockDiff'
 import type { DiffBase } from './diffBase'
+import { pageCard, pageMarks, sourceLines } from '../editor/pageBlocks'
 import { splitLines } from '../editText'
 import { diffBlockTrees } from './blockDiff'
 
-/** 删掉的一块（见 RemovedBlock），带上种类的名字：旧版本里才有的种类，新文件的筛选属性里查不到它叫什么。 */
-export interface RemovedView extends RemovedBlock {
+/** 删掉的一块（见 RemovedBlock）发给页面的样子：旧版本里它自己的内容（见 pageCard），带上种类的名字（旧版本里才有的种类，新文件的筛选属性里查不到它叫什么）。 */
+export interface RemovedView extends Omit<RemovedBlock, 'block'> {
+  block: PageCard
   kindName: string
 }
 
@@ -49,6 +52,20 @@ function kindNames(attributes: readonly FileAttribute[]): Map<string, string> {
   return new Map(attributes.find(attribute => attribute.id === 'kind')?.values.map(value => [value.id, value.name]))
 }
 
+/** 各块的开头（第一行的行首）在文件里的下标，按块的记号：卡片里要标的改动发给页面时从块的开头算（见 pageMarks） */
+function blockStarts({ blocks, source }: SentDocument): Map<string, number> {
+  const lines = sourceLines(source)
+  const starts = new Map<string, number>()
+  const visit = (list: readonly BlockView[]): void => {
+    for (const block of list) {
+      starts.set(block.anchor, lines.start(block.startLine))
+      visit(block.children)
+    }
+  }
+  visit(blocks)
+  return starts
+}
+
 /** 按基准比出来的差异：基准里没有这个文件时整份是新文件，否则两棵块树比（见 diffBlockTrees）。 */
 export function documentDiff(base: DiffBase, sent: SentDocument, old: { source: string, document: OldDocument } | null): DocumentDiff {
   const common = { base: base.label, version: sent.version, lineCount: splitLines(sent.source).length }
@@ -56,7 +73,13 @@ export function documentDiff(base: DiffBase, sent: SentDocument, old: { source:
     return { ...common, newFile: base.missing, blocks: {}, removed: [], stats: NO_CHANGES }
   const { blocks, removed, stats } = diffBlockTrees({ blocks: old.document.blocks, source: old.source }, sent)
   const kinds = kindNames(old.document.attributes)
-  return { ...common, blocks, removed: removed.map(item => ({ ...item, kindName: kinds.get(item.block.kind) ?? item.block.kind })), stats }
+  const starts = blockStarts(sent)
+  return {
+    ...common,
+    blocks: Object.fromEntries(Object.entries(blocks).map(([anchor, changed]) => [anchor, changed.marks ? { ...changed, marks: pageMarks(changed.marks, starts.get(anchor) ?? 0) } : changed])),
+    removed: removed.map(item => ({ ...item, block: pageCard(item.block, 0), kindName: kinds.get(item.block.kind) ?? item.block.kind })),
+    stats,
+  }
 }
 
 /**