A string parser using dfa state machine
npm install slow-dfa-string-parsernpm i slow-dfa-string-parser@1.0.0 --save2d-array to realize dfa c++, you can think inline, rewrite the code and insert function into hooks. It will reduce function call expense, improve performance.- - -
Typescript to develop, you can edit module type in the tsconfig.json and recompile it.``javascript`
const { DFA_map } = require('slow-dfa-string-parser');
##### DeclarestypescriptstatesMapping
declare interface DFA_map_descriptor {
match: Array
no_match_go_state?: string | number;
currentState: string | number | Array
nextState: string | number | Array
//the dfa state can be string or number
//if currentState or nextState using array, the index should be matched.
do?: Function | void; //the function that will be executed in 'DFA_map_instance.next();'
};
class DFA_map {
public inputString: string;
public readPosition: number;
private currentState: number;
private states: Array
private optimizeStateCount: number; //count of the states count that store in mapping
constructor(descriptor: DFA_map_descriptor[], initState: string | number, onlyAscii: boolean = true) {};
getCurrentState(): number | string {};
next(...args: any[]): void {};
end(): boolean {};
getInputString(): string {};
setInputString(str: string) {};
getReadPosition(): number {};
setReadPosition(n: number) {};
getStringSize(): number {};
};
`
- - -$3
Please see the dictionary in the
There is one:
`typescript
const { DFA_map } = require('../dist');
//request: split string by ':', not split the string in quotes(single quote)
console.time('Create DFA time');
const dfa = new DFA_map([
{
match: [
'*',
],
currentState: 'normal',
nextState: 'normal',
do: function(ch) {
if (ch !== ':') {
if (!result[result.length - 1]) result[result.length - 1] = [];
result[result.length - 1].push(ch); //join char
} else {
//split
if (!result[result.length - 1]) result[result.length - 1] = [];
result[result.length - 1] = result[result.length - 1].join('');
result[result.length] = [];
}
}
},
{
match: [
'*',
],
currentState: 'in-quote',
nextState: 'in-quote',
do: function (ch) {
if (!result[result.length - 1]) result[result.length - 1] = [];
result[result.length - 1].push(ch); //join char
}
},
{
match: [
'\''
],
currentState: ['normal', 'in-quote'],
nextState: ['in-quote', 'normal'],
do: function (ch) {
if (!result[result.length - 1]) result[result.length - 1] = [];
result[result.length - 1].push(ch); //join char
}
},
], 'normal', true);
console.timeEnd('Create DFA time');
//notice data: the pattern in the end will cover the pattern in the beginning
const result = [[]];
dfa.setInputString('a:b:c:d:123:\'Hello:Pig\':pig"a:b"\'c:d\'');
console.time('Run time');
try {
while (1) dfa.next();
} catch (e) { console.warn(e); }
result[result.length - 1] = result[result.length - 1].join(''); //join end
console.log('result',result);
console.timeEnd('Run time');
``