ethers.js/src.ts/wordlists/decode-owl.ts
2022-11-27 21:45:42 -05:00

59 lines
1.7 KiB
TypeScript

import { assertArgument } from "../utils/index.js";
const subsChrs = " !#$%&'()*+,-./<=>?@[]^_`{|}~";
const Word = /^[a-z]*$/i;
function unfold(words: Array<string>, sep: string): Array<string> {
let initial = 97;
return words.reduce((accum, word) => {
if (word === sep) {
initial++;
} else if (word.match(Word)) {
accum.push(String.fromCharCode(initial) + word);
} else {
initial = 97;
accum.push(word);
}
return accum;
}, <Array<string>>[]);
}
/**
* @_ignore
*/
export function decode(data: string, subs: string): Array<string> {
// Replace all the substitutions with their expanded form
for (let i = subsChrs.length - 1; i >= 0; i--) {
data = data.split(subsChrs[i]).join(subs.substring(2 * i, 2 * i + 2));
}
// Get all tle clumps; each suffix, first-increment and second-increment
const clumps: Array<string> = [ ];
const leftover = data.replace(/(:|([0-9])|([A-Z][a-z]*))/g, (all, item, semi, word) => {
if (semi) {
for (let i = parseInt(semi); i >= 0; i--) { clumps.push(";"); }
} else {
clumps.push(item.toLowerCase());
}
return "";
});
/* c8 ignore start */
if (leftover) { throw new Error(`leftovers: ${ JSON.stringify(leftover) }`); }
/* c8 ignore stop */
return unfold(unfold(clumps, ";"), ":");
}
/**
* @_ignore
*/
export function decodeOwl(data: string): Array<string> {
assertArgument(data[0] === "0", "unsupported auwl data", "data", data);
return decode(
data.substring(1 + 2 * subsChrs.length),
data.substring(1, 1 + 2 * subsChrs.length));
}