asearch - くたくたじゅうよん

asearch

あいまい検索 algorithm

ESModule用

code:script.js

export class Asearch {

get INITPAT() {return 0x80000000;} // 0100,0000,0000,0000,0000,0000,0000,0000

get MAXCHAR() {return 0x100;} // 256文字が上限

get INITSTATE() {return this.INITPAT, 0, 0, 0;}

constructor(source) {

this.shiftpat = Array(this.MAXCHAR).map(_ => 0);

this.epsilon = 0;

let mask = this.INITPAT;

for (const item of this.unpack(source)) {

// 0x20 is a space

if (item === 0x20) {

this.epsilon |= mask;

} else {

this.shiftpatitem |= mask;

this.shiftpatthis.toupper(item) |= mask;

this.shiftpatthis.tolower(item) |= mask;

mask >>>= 1;

}

this.acceptpat = mask;

}

tolower(c) {

return this.isupper(c) ? c + 0x20 : c;

}

toupper(c) {

return this.islower(c) ? c - 0x20 : c;

}

isupper(c) {

// 0x41 = A, 0x5a = Z

return (c >= 0x41) && (c <= 0x5a);

}

islower(c) {

// 0x61 = a, 0x7a = z

return (c >= 0x61) && (c <= 0x7a);

}

state(str = '') {

let i0 = this.INITSTATE0;

let i1 = this.INITSTATE1;

let i2 = this.INITSTATE2;

let i3 = this.INITSTATE3;

for (const item of this.unpack(str)) {

const mask = this.shiftpatitem;

i3 = (i3 & this.epsilon) | ((i3 & mask) >>> 1) | (i2 >>> 1) | i2;

i2 = (i2 & this.epsilon) | ((i2 & mask) >>> 1) | (i1 >>> 1) | i1;

i1 = (i1 & this.epsilon) | ((i1 & mask) >>> 1) | (i0 >>> 1) | i0;

i0 = (i0 & this.epsilon) | ((i0 & mask) >>> 1);

i1 |= i0 >>> 1;

i2 |= i1 >>> 1;

i3 |= i2 >>> 1;

}

return i0, i1, i2, i3;

}

match(str, ambig = 0) {

ambig = ambig < this.INITSTATE.length ? ambig : this.INITSTATE.length - 1;

const s = this.state(str);

return (sambig & this.acceptpat) !== 0;

}

// UTF-16 code pointを上8bitと下8bitとに分割する

unpack(str) {

return str.split('')

.flatMap(char => {

const code = char.charCodeAt(0);

if (code > 0xFF) {

return (code & 0xFF00) >>> 8, code & 0xFF;

}

return code & 0xFF; // 下の8ビットを取得する

});

}

WebWorker用

code:worker.js

class Asearch {