extractLang()

从 code 元素的 className 中提取编程语言。

import { extractLang } from "@unifast/core";

签名

function extractLang(code: HastElement): string | null

参数

code

属性	类型	默认值	描述
`type`	`"element"`	—	节点类型标识
`tagName`	`string`	—	HTML 标签名（通常是 `"code"`）
`properties`	`Record<string, unknown>`	—	元素属性，包括 `className`
`children`	`HastNode[]`	—	元素的子节点

返回值

string | null —— 从首个 language-* 类名中提取出的语言标识；若未找到语言类名，则返回 null。

用法

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const codeElement: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["language-typescript"] },
  children: [{ type: "text", value: "const x = 1;" }],
};

const lang = extractLang(codeElement);

console.log(lang);
// typescript

示例

从 code 元素中提取语言

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["language-js", "highlight"] },
  children: [{ type: "text", value: "console.log('hello');" }],
};

console.log(extractLang(code));
// js

没有语言类名的情况

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["highlight"] },
  children: [{ type: "text", value: "plain text" }],
};

console.log(extractLang(code));
// null

className 不是数组的情况

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: {},
  children: [{ type: "text", value: "no classes" }],
};

console.log(extractLang(code));
// null

与 findCodeChild 配合使用

import { extractLang, findCodeChild } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const pre: HastElement = {
  type: "element",
  tagName: "pre",
  properties: {},
  children: [
    {
      type: "element",
      tagName: "code",
      properties: { className: ["language-python"] },
      children: [{ type: "text", value: "print('hello')" }],
    },
  ],
};

const code = findCodeChild(pre);
if (code) {
  console.log(extractLang(code));
  // python
}