feat(代码配色): 代码里的全角标点（print（“你好”）、！=、全角空格）标红加波浪线；Python 的 int / str / list 一律青绿色，print 一律是函数色，"%.f" 也认了

12 万条 Python 提交里，代码里带全角标点的 1947 条全部编译出错，占 Python 编译错误的五分之一，
原来的配色下 “你好” 被认成变量名，看着和正常代码一样。

int 原来是 int(input()) 里棕色、map(int, …) 里深蓝；print 碰上 print"yes"、print（c） 会变成
关键字蓝。现在都照 VS Code。C 的解析器碰到全角标点会把后半行当成没有引号的「字符串」，
这种不算字符串，里面的全角标点照样标。

补的这几种标记合在 shared/codeMarks.ts 一处（原 formatPlaceholder.ts），编辑器和静态代码共用；
Python 解析器的补丁挪到 extensions/pythonLanguage.ts，免得 language → codeMarks → highlight 绕圈。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/shared/codeMarks.ts

@@ -0,0 +1,132 @@
+/**
+ * 在 lezer 分好的词上再补的几种标记。lezer 给不了、但学生的代码里很常见，所以另外扫一遍。
+ * 静态代码在 shared/highlight.ts 里拆 span，编辑器在 shared/extensions/codeMarks.ts 里挂装饰，
+ * 两边都只调 extraMarks()，颜色才一样。
+ *
+ * - 字符串里的格式占位符：printf 的 %d、%.2f、%%，Python 的 "%d 个" % n。
+ *   正则和颜色照 VS Code 的语法文件：C 是 constant.other.placeholder（变量色），
+ *   Python 是 constant.character.format.placeholder（关键字色），所以两种语言类名不同。
+ *   写错的（%,2f、%。1f、%S）故意不认，不变色正好提醒学生。
+ * - 字符串和注释之外的全角标点（`print（“你好”）`、`！=`、全角空格）：标红加波浪线。
+ *   12 万条 Python 提交里有 1947 条是这样，全部编译出错，占 Python 编译错误的五分之一，
+ *   不标的话 `“你好”` 会被认成变量名，看着和正常代码一样。
+ * - Python 的内置类型（int、str、list…）：照 VS Code 一律是类型色。lezer 只按位置分，
+ *   `int(input())` 里是函数、`map(int, …)` 里是变量，同一行两个颜色。
+ */
+import type { syntaxTree } from "@codemirror/language"
+
+type Tree = ReturnType<typeof syntaxTree>
+
+export type CodeFamily = "c" | "python"
+
+export interface Mark {
+  from: number
+  to: number
+  cls: string
+}
+
+const FORMAT: Record<CodeFamily, RegExp> = {
+  c: /%(\d+\$)?[#0\- +']*(-?\d+|\*)?(\.(-?\d+|\*)?)?(hh|h|ll|l|j|t|z|L)?[diouxXeEfFgGaAcspn%]/g,
+  python: /%(\([\w\s]*\))?[-+#0 ]*(\d+|\*)?(\.(\d+|\*)?)?[hlL]?[diouxXeEfFgGcrsa%]/g,
+}
+
+const FORMAT_CLASS: Record<CodeFamily, string> = {
+  c: "tok-format",
+  python: "tok-format-py",
+}
+
+// 全角的 ASCII（！（），：；？ａ１…）、全角空格、、。〈〉《》「」【】、中文引号
+const FULL_WIDTH = /[！-～　-。〈-】‘’“”]/g
+
+// VS Code（MagicPython）的 builtin-types
+const PY_BUILTIN_TYPES = new Set([
+  "bool",
+  "bytearray",
+  "bytes",
+  "classmethod",
+  "complex",
+  "dict",
+  "float",
+  "frozenset",
+  "int",
+  "list",
+  "object",
+  "property",
+  "set",
+  "slice",
+  "staticmethod",
+  "str",
+  "super",
+  "tuple",
+  "type",
+])
+
+function matches(text: string, re: RegExp, cls: string): Mark[] {
+  return [...text.matchAll(re)].map((m) => ({ from: m.index, to: m.index + m[0].length, cls }))
+}
+
+/**
+ * 一个词（lezer 吐出的一段文字和它的类名）上要补的标记，位置相对 text 开头。
+ * prev 是这段文字前面那个字符，用来排除 `obj.int` 这种属性
+ */
+export function extraMarks(
+  text: string,
+  classes: string,
+  family: CodeFamily,
+  prev: string,
+): Mark[] {
+  if (classes.includes("tok-string")) return matches(text, FORMAT[family], FORMAT_CLASS[family])
+  if (classes.includes("tok-comment")) return []
+  if (
+    family === "python" &&
+    prev !== "." &&
+    (classes === "tok-function" || classes === "tok-variable") &&
+    PY_BUILTIN_TYPES.has(text)
+  ) {
+    return [{ from: 0, to: text.length, cls: "tok-builtin-type" }]
+  }
+  return matches(text, FULL_WIDTH, "tok-fullwidth")
+}
+
+/**
+ * 不是字符串的「字符串」：lezer 的 C 解析器碰到全角标点会把后面一截当成没有引号的 String 节点
+ * （`printf("%d\\n"， a)；` 里的 `， a)；`），整截染成字符串色、全角标点也就不标了。
+ * 开头不是引号（前面可以有 u8 / L / R / f / b 这类前缀）的 String 一律不算字符串
+ */
+export function fakeStrings(
+  tree: Tree,
+  read: (from: number, to: number) => string,
+  from = 0,
+  to?: number,
+): { from: number; to: number }[] {
+  const out: { from: number; to: number }[] = []
+  tree.iterate({
+    from,
+    to,
+    enter: (n) => {
+      if (n.name === "String" && !/^[uUlLrRbBfF8]*["']/.test(read(n.from, n.from + 4))) {
+        out.push({ from: n.from, to: n.to })
+      }
+    },
+  })
+  return out
+}
+
+/** 按 extraMarks 把一段文字拆开，每段带上补的类名 */
+export function splitMarks(
+  text: string,
+  classes: string,
+  /** 判断补什么标记用的类名，平时就是 classes；假字符串（见 fakeStrings）传空 */
+  marksFor: string,
+  family: CodeFamily,
+  prev: string,
+  put: (text: string, classes: string) => void,
+) {
+  let at = 0
+  for (const m of extraMarks(text, marksFor, family, prev)) {
+    if (m.from > at) put(text.slice(at, m.from), classes)
+    put(text.slice(m.from, m.to), classes ? `${classes} ${m.cls}` : m.cls)
+    at = m.to
+  }
+  if (at < text.length) put(text.slice(at), classes)
+}

apps/web/src/shared/components/CodeEditor.vue

@@ -1,7 +1,4 @@
 <script lang="ts" setup>
-import { cpp } from "@codemirror/lang-cpp"
-import { python } from "@codemirror/lang-python"
-import { sql, SQLite } from "@codemirror/lang-sql"
 import { bracketMatching } from "@codemirror/language"
 import CodeMirror from "./CodeMirror.vue"
 import type { Extension } from "@codemirror/state"
@@ -10,6 +7,7 @@ import type { LANGUAGE } from "utils/types"
 import { darkCodeTheme, lightCodeTheme } from "../themes/codeTheme"
 import { styleTheme } from "shared/extensions/baseTheme"
 import { enhanceCompletion } from "shared/extensions/autocompletion"
+import { languageExtension } from "shared/extensions/language"
 
 interface Props {
   language?: LANGUAGE
@@ -33,10 +31,7 @@ const code = defineModel<string>("value")
 
 const isDark = useDark()
 
-const langExtension = computed(() => {
-  if (language === "SQL") return sql({ dialect: SQLite, upperCaseKeywords: true })
-  return language === "Python" ? python() : cpp()
-})
+const langExtension = computed(() => languageExtension(language))
 
 const extensions = computed(() => [
   styleTheme,

apps/web/src/shared/extensions/codeMarks.ts

@@ -0,0 +1,67 @@
+import { syntaxTree } from "@codemirror/language"
+import type { Extension, Range } from "@codemirror/state"
+import { Decoration, type DecorationSet, type EditorView, ViewPlugin } from "@codemirror/view"
+import { highlightTree } from "@lezer/highlight"
+import { type CodeFamily, extraMarks, fakeStrings } from "../codeMarks"
+import { codeHighlighter } from "../highlight"
+
+/**
+ * 编辑器里补的标记（%d、全角标点、Python 内置类型），规则见 shared/codeMarks.ts。
+ * 和静态代码一样按 codeHighlighter 分出来的词逐个过 extraMarks()；只扫看得见的部分。
+ */
+export function codeMarks(family: CodeFamily): Extension {
+  const decos = new Map<string, Decoration>()
+  const deco = (cls: string) => {
+    let d = decos.get(cls)
+    if (!d) decos.set(cls, (d = Decoration.mark({ class: cls })))
+    return d
+  }
+
+  function build(view: EditorView): DecorationSet {
+    const tree = syntaxTree(view.state)
+    const ranges: Range<Decoration>[] = []
+    for (const { from, to } of view.visibleRanges) {
+      const text = view.state.doc.sliceString(from, to)
+      const fake = fakeStrings(tree, (a, b) => view.state.doc.sliceString(a, b), from, to)
+      const prev = (pos: number) => (pos > from ? text[pos - from - 1] : "")
+      const add = (start: number, end: number, classes: string) => {
+        if (fake.some((r) => start >= r.from && start < r.to)) classes = ""
+        for (const m of extraMarks(
+          text.slice(start - from, end - from),
+          classes,
+          family,
+          prev(start),
+        )) {
+          ranges.push(deco(m.cls).range(start + m.from, start + m.to))
+        }
+      }
+      // highlightTree 只吐有类名的词，中间没类名的空档（全角标点多半在这里）另外补
+      let at = from
+      highlightTree(
+        tree,
+        codeHighlighter,
+        (start, end, classes) => {
+          if (start > at) add(at, start, "")
+          add(start, end, classes)
+          at = end
+        },
+        from,
+        to,
+      )
+      if (to > at) add(at, to, "")
+    }
+    return Decoration.set(ranges, true)
+  }
+
+  return ViewPlugin.define(
+    (view) => ({
+      decorations: build(view),
+      update(u) {
+        if (u.docChanged || u.viewportChanged || syntaxTree(u.startState) !== syntaxTree(u.state)) {
+          this.decorations = build(u.view)
+        }
+      },
+    }),
+    { decorations: (v) => v.decorations },
+  )
+}

apps/web/src/shared/extensions/language.ts

@@ -1,8 +1,11 @@
 import { cpp } from "@codemirror/lang-cpp"
 import { python } from "@codemirror/lang-python"
 import { sql, SQLite } from "@codemirror/lang-sql"
+import { LanguageSupport } from "@codemirror/language"
 import type { Extension } from "@codemirror/state"
 import type { LANGUAGE } from "utils/types"
+import { codeMarks } from "./codeMarks"
+import { ojPythonLanguage } from "./pythonLanguage"
 
 /**
  * 语言对应的高亮扩展。学生端和教师端共用同一份（两边都是题目页上的 SyncCodeEditor） ——
@@ -12,5 +15,8 @@ import type { LANGUAGE } from "utils/types"
  */
 export function languageExtension(language: LANGUAGE): Extension {
   if (language === "SQL") return sql({ dialect: SQLite, upperCaseKeywords: true })
-  return language === "Python" ? python() : cpp()
+  if (language === "Python") {
+    return [new LanguageSupport(ojPythonLanguage, python().support), codeMarks("python")]
+  }
+  return [cpp(), codeMarks("c")]
 }

apps/web/src/shared/extensions/pythonLanguage.ts

@@ -0,0 +1,23 @@
+import { pythonLanguage } from "@codemirror/lang-python"
+import { styleTags, tags as t } from "@lezer/highlight"
+
+/**
+ * Python 的解析器在上色上补几处，向 VS Code 看齐。编辑器（extensions/language.ts）和
+ * 静态代码（shared/highlight.ts）都用这一份，两边的颜色才一样。
+ *
+ * - `from` / `as` / `with` 和 `if`、`import` 一样算管流程的词（lezer 把 `from` 和 `def` 归成一类）
+ * - f-string 的 `{ }` 和 `:.2f` 一样是格式占位符的颜色
+ * - `print` 一律是函数：lezer 把不带括号的 `print`（Python 2 的写法）当关键字，`print"yes"`、
+ *   全角括号的 `print（c）` 就变成关键字色，和旁边的 `print(...)` 不一样
+ *
+ * 单独放一个文件是为了不绕圈：language.ts → codeMarks.ts → highlight.ts 要用到它。
+ */
+export const ojPythonLanguage = pythonLanguage.configure({
+  props: [
+    styleTags({
+      "from as with": t.controlKeyword,
+      "FormatReplacement/{ FormatReplacement/} FormatSpec/:": t.modifier,
+      print: t.function(t.variableName),
+    }),
+  ],
+})

apps/web/src/shared/highlight.css

@@ -14,6 +14,7 @@
   --code-type: #267f99;
   --code-comment: #008000;
   --code-invalid: #cd3131;
+  --code-invalid-bg: rgba(205, 49, 49, 0.12);
   --code-heading: #800000;
   --code-raw: #800000;
   --code-bold: #000080;
@@ -31,6 +32,7 @@ html.dark {
   --code-type: #4ec9b0;
   --code-comment: #6a9955;
   --code-invalid: #f44747;
+  --code-invalid-bg: rgba(244, 71, 71, 0.18);
   --code-heading: #569cd6;
   --code-raw: #ce9178;
   --code-bold: #569cd6;
@@ -67,6 +69,29 @@ html.dark {
   color: var(--code-invalid);
 }
 
+/* shared/codeMarks.ts 补的几种标记。静态代码是同一个 span 上的两个类名，编辑器里是两层 span、
+   谁包谁不一定，所以内外两种写法都要，并且要写在上面那些 tok-* 后面 */
+.tok-format,
+.tok-format * {
+  color: var(--code-variable);
+}
+.tok-format-py,
+.tok-format-py * {
+  color: var(--code-keyword);
+}
+.tok-builtin-type,
+.tok-builtin-type * {
+  color: var(--code-type);
+}
+.tok-fullwidth,
+.tok-fullwidth * {
+  color: var(--code-invalid);
+  background-color: var(--code-invalid-bg);
+  text-decoration: wavy underline var(--code-invalid);
+  text-decoration-skip-ink: none;
+  text-underline-offset: 3px;
+}
+
 /* 以下只有 Markdown 编辑器用得到 */
 .tok-heading {
   color: var(--code-heading);

apps/web/src/shared/highlight.ts

@@ -9,10 +9,11 @@
  * 只认判题机认的几种语言，别的语言和不标语言的代码块按原文显示。
  */
 import { cppLanguage } from "@codemirror/lang-cpp"
-import { pythonLanguage } from "@codemirror/lang-python"
 import { SQLite } from "@codemirror/lang-sql"
 import { highlightCode, tagHighlighter, tags as t } from "@lezer/highlight"
 import type { ConfigProviderProps } from "naive-ui"
+import { type CodeFamily, fakeStrings, splitMarks } from "./codeMarks"
+import { ojPythonLanguage } from "./extensions/pythonLanguage"
 
 /** 词的种类 → 类名。编辑器在 shared/themes/codeTheme.ts 里挂的也是它 */
 export const codeHighlighter = tagHighlighter([
@@ -41,9 +42,9 @@ type Parser = typeof cppLanguage.parser
 
 // C 和编辑器一样用 C++ 的解析器
 const PARSERS: Record<string, Parser> = {
-  python: pythonLanguage.parser,
-  py: pythonLanguage.parser,
-  python3: pythonLanguage.parser,
+  python: ojPythonLanguage.parser,
+  py: ojPythonLanguage.parser,
+  python3: ojPythonLanguage.parser,
   c: cppLanguage.parser,
   cpp: cppLanguage.parser,
   "c++": cppLanguage.parser,
@@ -54,6 +55,13 @@ function parserFor(lang?: string): Parser | null {
   return PARSERS[lang?.toLowerCase() ?? ""] ?? null
 }
 
+function familyFor(lang?: string): CodeFamily | null {
+  const parser = parserFor(lang)
+  if (parser === cppLanguage.parser) return "c"
+  if (parser === ojPythonLanguage.parser) return "python"
+  return null
+}
+
 export function escapeHtml(text: string): string {
   return text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;")
 }
@@ -74,7 +82,22 @@ function walk(
     put(code, "")
     return
   }
-  highlightCode(code, parser.parse(code), codeHighlighter, put, () => put("\n", ""))
+  // 再补 %d、全角标点、Python 内置类型这几种标记，见 shared/codeMarks.ts
+  const tree = parser.parse(code)
+  const family = familyFor(lang)
+  const fake = family ? fakeStrings(tree, (from, to) => code.slice(from, to)) : []
+  let pos = 0
+  const emit = (text: string, classes: string) => {
+    if (family) {
+      const marks = fake.some((r) => pos >= r.from && pos < r.to) ? "" : classes
+      splitMarks(text, classes, marks, family, code[pos - 1] ?? "", put)
+    } else put(text, classes)
+    pos += text.length
+  }
+  highlightCode(code, tree, codeHighlighter, emit, () => {
+    put("\n", "")
+    pos++
+  })
 }
 
 /** 逐行高亮，返回每行的 HTML，每行的标签自己闭合 */