Jina 公司的 CEO 肖涵在 GitHub 上分享了一个令人印象深刻的代码片段，这段代码是 Jina tokenizer 中使用的核心分词实现。这个正则表达式代码片段仅用了 50 余行，却能够高效地处理各种复杂度的文本内容进行分块。其性能之强劲令人惊讶。
在线体验：https://jina.ai/tokenizer/
// Updated: Aug. 15, 2024
// Run: node testRegex.js testText.txt
// Used in https://jina.ai/tokenizer
const fs = require('fs');
const util = require('util');
// Define variables for magic numbers
const MAX_HEADING_LENGTH = 7;
const MAX_HEADING_CONTENT_LENGTH = 200;
const MAX_HEADING_UNDERLINE_LENGTH = 200;
const MAX_HTML_HEADING_ATTRIBUTES_LENGTH = 100;
const MAX_LIST_ITEM_LENGTH = 200;
const MAX_NESTED_LIST_ITEMS = 6;
const MAX_LIST_INDENT_SPACES = 7;
const MAX_BLOCKQUOTE_LINE_LENGTH = 200;
const MAX_BLOCKQUOTE_LINES = 15;
const MAX_CODE_BLOCK_LENGTH = 1500;
const MAX_CODE_LANGUAGE_LENGTH = 20;
const MAX_INDENTED_CODE_LINES = 20;
const MAX_TABLE_CELL_LENGTH = 200;
const MAX_TABLE_ROWS = 20;
const MAX_HTML_TABLE_LENGTH = 2000;
const MIN_HORIZONTAL_RULE_LENGTH = 3;
const MAX_SENTENCE_LENGTH = 400;
const MAX_QUOTED_TEXT_LENGTH = 300;
const MAX_PARENTHETICAL_CONTENT_LENGTH = 200;
const MAX_NESTED_PARENTHESES = 5;
const MAX_MATH_INLINE_LENGTH = 100;
const MAX_MATH_BLOCK_LENGTH = 500;
const MAX_PARAGRAPH_LENGTH = 1000;
const MAX_STANDALONE_LINE_LENGTH = 800;
const MAX_HTML_TAG_ATTRIBUTES_LENGTH = 100;
const MAX_HTML_TAG_CONTENT_LENGTH = 1000;
const LOOKAHEAD_RANGE = 100; // Number of characters to look ahead for a sentence boundary
// Define the regex pattern
// Headings
// Citations
// List items
// Block quotes
// Code blocks
// Tables
// Horizontal rules
// Standalone lines or phrases
// Sentences or phrases
// Quoted text, parenthetical phrases, or bracketed content
// Paragraphs
// HTML-like tags and their content
// LaTeX-style math expressions
// Fallback for any remaining content
// Read the regex and test text from files
const chunkRegex = new RegExp(
"(" +
// 1. Headings (Setext-style, Markdown, and HTML-style, with length constraints)
`(?:^(?:[#*=-]{1,${MAX_HEADING_LENGTH}}|\\w[^\\r\\n]{0,${MAX_HEADING_CONTENT_LENGTH}}\\r?\\n[-=]{2,${MAX_HEADING_UNDERLINE_LENGTH}}|<h[1-6][^>]{0,${MAX_HTML_HEADING_ATTRIBUTES_LENGTH}}>)[^\\r\\n]{1,${MAX_HEADING_CONTENT_LENGTH}}(?:</h[1-6]>)?(?:\\r?\\n|$))` +
"|" +
// New pattern for citations
`(?:\\[[0-9]+\\][^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}})` +
"|" +
// 2. List items (bulleted, numbered, lettered, or task lists, including nested, up to three levels, with length constraints)
`(?:(?:^|\\r?\\n)[ \\t]{0,3}(?:[-*+•]|\\d{1,3}\\.\\w\\.|\\[[ xX]\\])[ \\t]+(?:(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[\\r\\n]|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))` +
`(?:(?:\\r?\\n[ \\t]{2,5}(?:[-*+•]|\\d{1,3}\\.\\w\\.|\\[[ xX]\\])[ \\t]+(?:(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[\\r\\n]|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?)))` +
`{0,${MAX_NESTED_LIST_ITEMS}}(?:\\r?\\n[ \\t]{4,${MAX_LIST_INDENT_SPACES}}(?:[-*+•]|\\d{1,3}\\.\\w\\.|\\[[ xX]\\])[ \\t]+(?:(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[\\r\\n]|$))|(?:\\b[^\\r\\n]{1,${MAX_LIST_ITEM_LENGTH}}\\b(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?)))` +
`{0,${MAX_NESTED_LIST_ITEMS}})?)` +
"|" +
// 3. Block quotes (including nested quotes and citations, up to three levels, with length constraints)
`(?:(?:^>(?:>|\\s{2,}){0,2}(?:(?:\\b[^\\r\\n]{0,${MAX_BLOCKQUOTE_LINE_LENGTH}}\\b(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:\\b[^\\r\\n]{0,${MAX_BLOCKQUOTE_LINE_LENGTH}}\\b(?=[\\r\\n]|$))|(?:\\b[^\\r\\n]{0,${MAX_BLOCKQUOTE_LINE_LENGTH}}\\b(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))\\r?\\n?){1,${MAX_BLOCKQUOTE_LINES}})` +
"|" +
// 4. Code blocks (fenced, indented, or HTML pre/code tags, with length constraints)
`(?:(?:^|\\r?\\n)(?:\`\`\`|~~~)(?:\\w{0,${MAX_CODE_LANGUAGE_LENGTH}})?\\r?\\n[\\s\\S]{0,${MAX_CODE_BLOCK_LENGTH}}?(?:\`\`\`|~~~)\\r?\\n?` +
`|(?:(?:^|\\r?\\n)(?: {4}|\\t)[^\\r\\n]{0,${MAX_LIST_ITEM_LENGTH}}(?:\\r?\\n(?: {4}|\\t)[^\\r\\n]{0,${MAX_LIST_ITEM_LENGTH}}){0,${MAX_INDENTED_CODE_LINES}}\\r?\\n?)` +
`|(?:<pre>(?:<code>)?[\\s\\S]{0,${MAX_CODE_BLOCK_LENGTH}}?(?:</code>)?</pre>))` +
"|" +
// 5. Tables (Markdown, grid tables, and HTML tables, with length constraints)
`(?:(?:^|\\r?\\n)(?:\\|[^\\r\\n]{0,${MAX_TABLE_CELL_LENGTH}}\\|(?:\\r?\\n\\|[-:]{1,${MAX_TABLE_CELL_LENGTH}}\\|){0,1}(?:\\r?\\n\\|[^\\r\\n]{0,${MAX_TABLE_CELL_LENGTH}}\\|){0,${MAX_TABLE_ROWS}}` +
`|<table>[\\s\\S]{0,${MAX_HTML_TABLE_LENGTH}}?</table>))` +
"|" +
// 6. Horizontal rules (Markdown and HTML hr tag)
`(?:^(?:[-*_]){${MIN_HORIZONTAL_RULE_LENGTH},}\\s*$|<hr\\s*/?>)` +
"|" +
// 10. Standalone lines or phrases (including single-line blocks and HTML elements, with length constraints)
`(?:^(?:<[a-zA-Z][^>]{0,${MAX_HTML_TAG_ATTRIBUTES_LENGTH}}>)?(?:(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?:[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?=[\\r\\n]|$))|(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?=[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))(?:</[a-zA-Z]+>)?(?:\\r?\\n|$))` +
"|" +
// 7. Sentences or phrases ending with punctuation (including ellipsis and Unicode punctuation)
`(?:(?:[^\\r\\n]{1,${MAX_SENTENCE_LENGTH}}(?:[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:[^\\r\\n]{1,${MAX_SENTENCE_LENGTH}}(?=[\\r\\n]|$))|(?:[^\\r\\n]{1,${MAX_SENTENCE_LENGTH}}(?=[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.\\.\\.|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))` +
"|" +
// 8. Quoted text, parenthetical phrases, or bracketed content (with length constraints)
"(?:" +
`(?<!\\w)\"\"\"[^\"]{0,${MAX_QUOTED_TEXT_LENGTH}}\"\"\"(?!\\w)` +
`|(?<!\\w)(?:['\"\`'"])[^\\r\\n]{0,${MAX_QUOTED_TEXT_LENGTH}}\\1(?!\\w)` +
`|\\([^\\r\\n()]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}(?:\\([^\\r\\n()]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}\\)[^\\r\\n()]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}){0,${MAX_NESTED_PARENTHESES}}\\)` +
`|\\[[^\\r\\n\\[\\]]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}(?:\\[[^\\r\\n\\[\\]]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}\\][^\\r\\n\\[\\]]{0,${MAX_PARENTHETICAL_CONTENT_LENGTH}}){0,${MAX_NESTED_PARENTHESES}}\\]` +
`|\\$[^\\r\\n$]{0,${MAX_MATH_INLINE_LENGTH}}\\$` +
`|\`[^\`\\r\\n]{0,${MAX_MATH_INLINE_LENGTH}}\`` +
")" +
"|" +
// 9. Paragraphs (with length constraints)
`(?:(?:^|\\r?\\n\\r?\\n)(?:<p>)?(?:(?:[^\\r\\n]{1,${MAX_PARAGRAPH_LENGTH}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:[^\\r\\n]{1,${MAX_PARAGRAPH_LENGTH}}(?=[\\r\\n]|$))|(?:[^\\r\\n]{1,${MAX_PARAGRAPH_LENGTH}}(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))(?:</p>)?(?=\\r?\\n\\r?\\n|$))` +
"|" +
// 11. HTML-like tags and their content (including self-closing tags and attributes, with length constraints)
`(?:<[a-zA-Z][^>]{0,${MAX_HTML_TAG_ATTRIBUTES_LENGTH}}(?:>[\\s\\S]{0,${MAX_HTML_TAG_CONTENT_LENGTH}}?</[a-zA-Z]+>|\\s*/>))` +
"|" +
// 12. LaTeX-style math expressions (inline and block, with length constraints)
`(?:(?:\\$\\$[\\s\\S]{0,${MAX_MATH_BLOCK_LENGTH}}?\\$\\$)|(?:\\$[^\\$\\r\\n]{0,${MAX_MATH_INLINE_LENGTH}}\\$))` +
"|" +
// 14. Fallback for any remaining content (with length constraints)
`(?:(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))|(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?=[\\r\\n]|$))|(?:[^\\r\\n]{1,${MAX_STANDALONE_LINE_LENGTH}}(?=[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?:.{1,${LOOKAHEAD_RANGE}}(?:[.!?…]|\\.{3}|[\\u2026\\u2047-\\u2049]|[\\p{Emoji_Presentation}\\p{Extended_Pictographic}])(?=\\s|$))?))` +
")",
"gmu"
);
// read from the arg[1] file
const testText = fs.readFileSync(process.argv[2], 'utf8');
// Function to format bytes to a human-readable string
function formatBytes(bytes) {
if (bytes < 1024) return bytes + " bytes";
else if (bytes < 1048576) return (bytes / 1024).toFixed(2) + " KB";
else if (bytes < 1073741824) return (bytes / 1048576).toFixed(2) + " MB";
else return (bytes / 1073741824).toFixed(2) + " GB";
}
// Start measuring time and memory
const startTime = process.hrtime();
const startMemory = process.memoryUsage().heapUsed;
// Apply the regex
const matches = testText.match(chunkRegex);
// End measuring time and memory
const endTime = process.hrtime(startTime);
const endMemory = process.memoryUsage().heapUsed;
// Calculate execution time and memory usage
const executionTime = endTime[0] + endTime[1] / 1e9;
const memoryUsed = endMemory - startMemory;
// Output results
console.log(`Number of chunks: ${matches ? matches.length : 0}`);
console.log(`Execution time: ${executionTime.toFixed(3)} seconds`);
console.log(`Memory used: ${formatBytes(memoryUsed)}`);
// Output the first 5 matches (or fewer if there are less than 5)
console.log('\nFirst 10 chunks:');
if (matches) {
matches.slice(0, 100).forEach((match, index) => {
console.log(util.inspect(match, {maxStringLength: 50}));
});
} else {
console.log('No chunks found.');
}
// Output regex flags
console.log(`\nRegex flags: ${chunkRegex.flags}`);
// Check for potential issues
if (executionTime > 5) {
console.warn('\nWarning: Execution time exceeded 5 seconds. The regex might be too complex or the input too large.');
}
if (memoryUsed > 100 * 1024 * 1024) {
console.warn('\nWarning: Memory usage exceeded 100 MB. Consider processing the input in smaller chunks.');
}
这段代码的正则表达式考虑了多种文本结构，包括标题、列表项、区块引用、代码块、表格、水平规则、独立行或短语、句子或带有标点的短语、引用文本、圆括号内容、代码块、表格、水平规则、独立行或短语、HTML 标签内容、LaTeX 数学表达式等。它通过精心设计的模式来近似文本分块，尽管正则表达式本身并不理解文本的上下文或语义。
代码示例中的正则表达式使用了“回溯”功能，这对于实现更有意义的语义分割至关重要。例如，它不会在句子中间进行断开。然而，对于深度嵌套的列表、区块引用或括号等结构，回溯可能会遇到困难。为了优化这些情况，可以进一步改进正则表达式，以更好地处理多级嵌套，并将嵌套限制在实用水平，比如最多 3 级，以确保性能并避免灾难性回溯。
尽管目前这段代码可能还不是十分完备，但按照这个思路不断优化细节，可以预见效果还有进一步提升的空间。Jina 官方提供了云服务分词器接口供开发者体验使用，并且是免费的。
python版本
