Files
obsidian-tannersearch/src/search/tokenizer.ts

94 lines
2.6 KiB
TypeScript

import type { QueryCombination } from 'minisearch'
import {
BRACKETS_AND_SPACE,
SPACE_OR_PUNCTUATION,
chsRegex,
getChsSegmenter,
} from 'src/globals'
import { getSettings } from 'src/settings'
import { logDebug, splitCamelCase, splitHyphens } from 'src/tools/utils'
const markdownLinkExtractor = require('markdown-link-extractor')
function tokenizeWords(text: string, { skipChs = false } = {}): string[] {
const tokens = text.split(BRACKETS_AND_SPACE)
if (skipChs) return tokens
return tokenizeChsWord(tokens)
}
function tokenizeTokens(text: string, { skipChs = false } = {}): string[] {
const tokens = text.split(SPACE_OR_PUNCTUATION)
if (skipChs) return tokens
return tokenizeChsWord(tokens)
}
function tokenizeChsWord(tokens: string[]): string[] {
const segmenter = getChsSegmenter()
if (!segmenter) return tokens
return tokens.flatMap(word =>
chsRegex.test(word) ? segmenter.cut(word, { search: true }) : [word]
)
}
/**
* Tokenization for indexing will possibly return more tokens than the original text.
* This is because we combine different methods of tokenization to get the best results.
* @param text
* @returns
*/
export function tokenizeForIndexing(text: string): string[] {
const words = tokenizeWords(text)
let urls: string[] = []
if (getSettings().tokenizeUrls) {
try {
urls = markdownLinkExtractor(text)
} catch (e) {
logDebug('Error extracting urls', e)
}
}
let tokens = tokenizeTokens(text, { skipChs: true })
// Split hyphenated tokens
tokens = [...tokens, ...tokens.flatMap(splitHyphens)]
// Split camelCase tokens into "camel" and "case
tokens = [...tokens, ...tokens.flatMap(splitCamelCase)]
// Add whole words (aka "not tokens")
tokens = [...tokens, ...words]
// Add urls
if (urls.length) {
tokens = [...tokens, ...urls]
}
// Remove duplicates
tokens = [...new Set(tokens)]
return tokens
}
/**
* Search tokenization will use the same tokenization methods as indexing,
* but will combine each group with "OR" operators
* @param text
* @returns
*/
export function tokenizeForSearch(text: string): QueryCombination {
// Extract urls and remove them from the query
const urls: string[] = markdownLinkExtractor(text)
text = urls.reduce((acc, url) => acc.replace(url, ''), text)
const tokens = [...tokenizeTokens(text), ...urls].filter(Boolean)
return {
combineWith: 'OR',
queries: [
{ combineWith: 'AND', queries: tokens },
{ combineWith: 'AND', queries: tokenizeWords(text).filter(Boolean) },
{ combineWith: 'AND', queries: tokens.flatMap(splitHyphens) },
{ combineWith: 'AND', queries: tokens.flatMap(splitCamelCase) },
],
}
}