ethers.js/lib.commonjs/wordlists/generation/encode-latin.js
2022-09-05 16:57:11 -04:00

353 lines
12 KiB
JavaScript

"use strict";
// OWL Data Format
//
// The Official WordList data format exported by this encoder
// encodes sorted latin-1 words (letters only) based on the
// fact that sorted words have prefixes with substantial
// overlap.
//
// For example, the words:
// [ Another, Apple, Apricot, Bread ]
// could be folded once with a single special character, such
// as ":" to yield:
// [ nother, pple, pricot, :, read ].
// The First letter has been removed, but can be inferred by
// starting at A and incrementing to the next letter when ":"
// is encountered.
//
// The fold operation can be repeated for large sets as even within
// each folded set, there is substatial overlap in prefix. With the
// second special symbol ";", we get:
// [ ; x 13, other, :, ple, ricot, :, ; x 18, ead ]
// which can be further compressed by using numbers instead of the
// special character:
// [ 13, other, :, ple, ricot, :, 18, ead ]
// and to keep all values within a single byte, we only allow a
// maximum value of 10 (using 0 through 9 to represent 1 through 10),
// we get:
// [ 9, 2, other, :, ple, ricot, :, 9, 7, ead ]
// and we use camel-case to imply the bounrary, giving the final string:
// "92Other:PleRicot:97Ead"
//
// Once the entire latin-1 set has been collapsed, we use the remaining
// printable characters (except " and \, which require 2 bytes to represent
// in string) to substiture for the most common 2-letter pairs of letters
// in the string.
//
// OWLA Accent Format
//
// OWLA first removes all accents, and encodes that data using the OWL
// data format and encodes the accents as a base-64 series of 6-bit
// packed bits representing the distance from one followed letter to the
// next.
//
// For example, the acute accent in a given language may follow either
// a or e, in which case the follow-set is "ae". Each letter in the entire
// set is indexed, so the set of words with the accents:
// "thisA/ppleDoe/sNotMa/tterToMe/"
// " 1^ 2^ 3^ 4^ 5^ 6^ " <-- follow-set members, ALL a's and e's
// which gives the positions:
// [ 0, 2, 3, 4, 6 ]
// which then reduce to the distances
// [ 0, 2, 1, 1, 2 ]
// each of which fit into a 2-bit value, so this can be encoded as the
// base-64 encoded string:
// 00 10 01 01 10 = 001001 1010xx
//
// The base-64 set used has all number replaced with their
// shifted-counterparts to prevent comflicting with the numbers used in
// the fold operation to indicate the number of ";".
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.encodeOwl = exports.extractAccents = exports.BitWriter = void 0;
const fs_1 = __importDefault(require("fs"));
const id_js_1 = require("../../hash/id.js");
const decode_owl_js_1 = require("../decode-owl.js");
const decode_owla_js_1 = require("../decode-owla.js");
const subsChrs = " !#$%&'()*+,-./<=>?@[]^_`{|}~";
const Word = /^[a-z'`]*$/i;
function fold(words, sep) {
const output = [];
let initial = 97;
for (const word of words) {
if (word.match(Word)) {
while (initial < word.charCodeAt(0)) {
initial++;
output.push(sep);
}
output.push(word.substring(1));
}
else {
initial = 97;
output.push(word);
}
}
return output;
}
function camelcase(words) {
return words.map((word) => {
if (word.match(Word)) {
return word[0].toUpperCase() + word.substring(1);
}
else {
return word;
}
}).join("");
}
//let cc = 0, ce = 0;
/*
function getChar(c: string): string {
//if (c === "e") { ce++; }
if (c >= 'a' && c <= 'z') { return c; }
if (c.charCodeAt(1)) {
throw new Error(`bad char: "${ c }"`);
}
//cc++;
return "";
if (c.charCodeAt(0) === 768) { return "`"; }
if (c.charCodeAt(0) === 769) { return "'"; }
if (c.charCodeAt(0) === 771) { return "~"; }
throw new Error(`Unsupported character: ${ c } (${ c.charCodeAt(0) }, ${ c.charCodeAt(1) })`);
}
function mangle(text: string): { word: string, special: string } {
const result: Array<string> = [ ];
for (let i = 0; i < text.length; i++) {
const c = getChar(text[i]);
result.push(c);
}
const word = result.join("");
if (word[1] >= 'a' && word[1] <= 'z') { return { word, special: " " }; }
return { word: word[0] + word.substring(2), special: word[1] };
}
*/
/*
Store: [ accent ][ targets ][ rle data; base64-tail ]
` ae 3, 100 = (63, 37), 15
~ n 63, 64 = (63, 1), 27
*/
const Base64 = ")!@#$%^&*(ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_";
class BitWriter {
width;
#data;
#bitLength;
constructor(width) {
this.width = width;
this.#data = [];
this.#bitLength = 0;
}
write(value) {
const maxValue = ((1 << this.width) - 1);
while (value > maxValue) {
this.#data.push(0);
this.#bitLength += this.width;
value -= maxValue;
}
this.#data.push(value);
this.#bitLength += this.width;
}
get length() {
return 1 + Math.trunc((this.#bitLength + 5) / 6);
}
get data() {
let result = String(this.width);
let bits = 0;
let accum = 0;
const data = this.#data.slice();
let bitMod = this.#bitLength % 6;
while (bitMod !== 0 && bitMod < 6) {
data.push(0);
bitMod += this.width;
}
for (const value of data) {
accum <<= this.width;
accum |= value;
bits += this.width;
if (bits < 6) {
continue;
}
result += Base64[accum >> (bits - 6)];
bits -= 6;
accum &= ((1 << bits) - 1);
}
if (result.length !== this.length) {
throw new Error(`Hmm: ${this.length} ${result.length} ${result}`);
}
return result;
}
}
exports.BitWriter = BitWriter;
;
function sorted(text) {
const letters = text.split("");
letters.sort();
return letters.join("");
}
// if (c.charCodeAt(0) === 768) { return "`"; }
// if (c.charCodeAt(0) === 769) { return "'"; }
// if (c.charCodeAt(0) === 771) { return "~"; }
function extractAccents(words) {
// Build a list that maps accents to the letters it can follow
const followsMap = new Map();
for (const word of words) {
for (let i = 0; i < word.length; i++) {
const c = word[i];
if (c >= 'a' && c <= 'z') {
continue;
}
// Make sure this positions and codepoint make sense
if (c.charCodeAt(1)) {
throw new Error(`unsupported codepoint: "${c}"`);
}
if (i === 0) {
throw new Error(`unmatched accent: ${c}`);
}
const ac = c.charCodeAt(0), lastLetter = word[i - 1];
;
const follows = (followsMap.get(ac) || "");
if (follows.indexOf(lastLetter) === -1) {
followsMap.set(ac, sorted(follows + lastLetter));
}
}
}
// Build the positions of each follow-set for those accents
const positionsMap = new Map();
for (const [accent, follows] of followsMap) {
let count = 0;
for (const word of words) {
for (let i = 0; i < word.length; i++) {
const c = word[i], ac = c.charCodeAt(0);
if (follows.indexOf(c) >= 0) {
count++;
}
if (ac === accent) {
const pos = positionsMap.get(ac) || [];
pos.push(count);
positionsMap.set(ac, pos);
}
}
}
}
const accents = [];
for (const [accent, follows] of followsMap) {
let last = -1;
const positions = (positionsMap.get(accent) || []).map((value, index) => {
const delta = value - last;
last = value;
if (index === 0) {
return value;
}
return delta;
});
// Find the best encoding of the position data
let positionData = "";
for (let i = 2; i < 7; i++) {
const bitWriter = new BitWriter(i);
for (const p of positions) {
bitWriter.write(p);
}
if (positionData === "" || bitWriter.length < positionData.length) {
positionData = bitWriter.data;
}
}
const positionsLength = positions.length;
const positionDataLength = positionData.length;
accents.push({ accent, follows, positions, positionsLength, positionData, positionDataLength });
}
words = words.map((word) => {
let result = "";
for (let i = 0; i < word.length; i++) {
const c = word[i];
if (c >= 'a' && c <= 'z') {
result += c;
}
}
return result;
});
return { accents, words };
}
exports.extractAccents = extractAccents;
// Encode Official WordList
function encodeOwl(words) {
// Fold the sorted words by indicating delta for the first 2 letters
let data = camelcase(fold(fold(words, ":"), ";"));
// Replace semicolons with counts (e.g. ";;;" with "3")
data = data.replace(/(;+)/g, (all, semis) => {
let result = "";
while (semis.length) {
let count = semis.length;
if (count > 10) {
count = 10;
}
result += String(count - 1);
semis = semis.substring(count);
}
return result;
});
// Finds the best option for a shortcut replacement using the
// unused ascii7 characters
function findBest() {
const tally = {};
const l = 2;
for (let i = l; i < data.length; i++) {
const key = data.substring(i - l, i);
tally[key] = (tally[key] || 0) + 1;
}
const sorted = Object.keys(tally).map((text) => {
return { text, count: tally[text], save: (tally[text] * (text.length - 1)) };
});
sorted.sort((a, b) => (b.save - a.save));
return sorted[0].text;
}
// Make substitutions
let subs = "";
for (let i = 0; i < subsChrs.length; i++) {
const n = subsChrs[i], o = findBest();
subs += o;
data = data.split(o).join(n);
}
return { data, subs };
}
exports.encodeOwl = encodeOwl;
// Returns either:
// - OWL data for accent-free latin-1: { data, accentds: "" }
// - OWLA data for accented latin-1: { data, accents }
function encodeWords(_words) {
const { accents, words } = extractAccents(_words);
const { data, subs } = encodeOwl(words);
const accentData = accents.map(({ accent, follows, positionData }) => {
return `${follows}${accent}${positionData}`;
}).join(",");
return {
data: `0${subs}${data}`,
accents: accentData
};
}
// CLI
const content = fs_1.default.readFileSync(process.argv[2]).toString();
const words = content.split("\n").filter(Boolean);
const { data, accents } = encodeWords(words);
if (accents) {
const rec = (0, decode_owla_js_1.decodeOwlA)(data, accents);
console.log("DATA: ", JSON.stringify(data));
console.log("ACCENTS: ", JSON.stringify(accents));
console.log("LENGTH: ", data.length);
console.log("CHECKSUM: ", (0, id_js_1.id)(content));
console.log("RATIO: ", Math.trunc(100 * data.length / content.length) + "%");
if (rec.join("\n") !== words.join("\n")) {
throw new Error("no match!");
}
}
else {
const rec = (0, decode_owl_js_1.decodeOwl)(data);
console.log("DATA: ", JSON.stringify(data));
console.log("LENGTH: ", data.length);
console.log("CHECKSUM: ", (0, id_js_1.id)(content));
console.log("RATIO: ", Math.trunc(100 * data.length / content.length) + "%");
if (rec.join("\n") !== words.join("\n")) {
throw new Error("no match!");
}
}
//# sourceMappingURL=encode-latin.js.map