aho-corasick-machine

Aho-Corasick machine for matching

Example

"use strict"

var createTrie = require("array-trie")
var createAC = require("../aho-corasick-machine.js")

var trie = createTrie()

console.log('trie.set([1,2,3,4],1234)\ntrie.set([2,3,4], 234)\ntrie.set([6,7,8], 678)\ntrie.set([1,2], 12)\ntrie.set([2,3], 23)\ntrie.set([3,4],34)')
trie.set([1,2,3,4],1234)
trie.set([2,3,4], 234)
trie.set([6,7,8], 678)
trie.set([1,2], 12)
trie.set([2,3], 23)
trie.set([3,4],34)

var automata = createAC(trie)

var data = [1,2,3,4,5,6,7,8,9]
console.log('ACmachine push:  [1,2,3,4,5,6,7,8,9]\nMatch: ')
var dataLength = data.length
for(var state=automata, i=0; i<dataLength; state=state.push(data[i++])) {
  if(state.value.length>0) {
    console.log(state.value)
  }
}

output:

trie.set([1,2,3,4],1234)
trie.set([2,3,4], 234)
trie.set([6,7,8], 678)
trie.set([1,2], 12)
trie.set([2,3], 23)
trie.set([3,4],34)
ACmachine push:  [1,2,3,4,5,6,7,8,9]
Match: 
[ 12 ]
[ 23 ]
[ 1234, 234, 34 ]
[ 678 ]

Install

npm install aho-corasick-machine

API

const createACMachine = require("aho-corasick-machine")

Constructor

let rootNode = createACMachine(trie)

Creates an Aho-Corasick machine from the trie encoded as an array-trie

Returns the root node of new Aho-Corasick Machine

Methods

node.push(symbol)

symbol is the next character in the stream to process

Return the next state of the automatic machine.

node.value

An array of the values where the stream matches

If no matches, its length is zero

node.next

A pointer to the next entry.

For example, when matching "1234" at node1, node1.next means it is matching "234"