modern-ahocorasick
npm install modern-ahocorasick> Forked from https://github.com/BrunoRB/ahocorasick and make it modern! Thanks to the author(BrunoRB) of ahocorasick
Implementation of the Aho-Corasick string searching algorithm, as described in the paper "Efficient string matching: an aid to bibliographic search".
this pkg has cjs and esm format, and have .d.ts file.
``sh`
npm i modern-ahocorasick
yarn add modern-ahocorasick
pnpm i modern-ahocorasick
`ts
// esm
import AhoCorasick from 'modern-ahocorasick'
// cjs
const AhoCorasick = require('modern-ahocorasick')
const ac = new AhoCorasick(['keyword1', 'keyword2', 'etc'])
const results = ac.search('should find keyword1 at position 19 and keyword2 at position 47.')
// [ [ 19, [ 'keyword1' ] ], [ 47, [ 'keyword2' ] ] ]
`
See
#### constructor(keywords: string[])
Initializes the Aho-Corasick state machine with the provided keywords.
Parameters:
- keywords: An array of strings representing the keywords to search for.
Example:
`typescript`
const keywords = ['he', 'she', 'his', 'hers']
const ac = new AhoCorasick(keywords)
---
#### search(str: string): [number, string[]][]
Searches the input string str for occurrences of any of the keywords and returns a list of matches.
Parameters:
- str: The input string to search.
Returns:
- An array of tuples. Each tuple contains:
- The ending index of the match in the input string.
- An array of matched keywords at that position.
Example:
`typescript
const ac = new AhoCorasick(['keyword1', 'keyword2', 'etc'])
const results = ac.search('should find keyword1 at position 19 and keyword2 at position 47.')
// [ [ 19, [ 'keyword1' ] ], [ 47, [ 'keyword2' ] ] ]
`
---
#### match(str: string): boolean
Checks if any keyword exists in the input string str.
Parameters:
- str: The input string to search.
Returns:
- true if any keyword is found.false
- otherwise.
Example:
`typescript`
const ac = new AhoCorasick(['he', 'she', 'his', 'hers'])
console.log(ac.match('ushers')) // Output: true
console.log(ac.match('xyz')) // Output: false
---
While the _buildTables method is not part of the public API, it is responsible for building the transition (gotoFn), output, and failure functions used by the Aho-Corasick algorithm.
---
`typescript
const keywords = ['cat', 'bat', 'rat']
const ac = new AhoCorasick(keywords)
const text = 'the cat chased the rat while a bat flew by'
const matches = ac.search(text)
`
`typescript
const ac = new AhoCorasick(['abc', '123'])
console.log(ac.match('hello abc world')) // Output: true
console.log(ac.match('hello world')) // Output: false
`
---
`typescript
const keywords = ['hello', 'world']
const ac = new AhoCorasick(keywords.map(k => k.toLowerCase()))
const text = 'Hello World'
const matches = ac.search(text.toLowerCase())
console.log(matches)
// Output: [
// [4, ["hello"]],
// [10, ["world"]]
// ]
`
This document serves as a complete guide for using the AhoCorasick` class for multi-pattern string matching.