romanize-string/dist/esm/transliterators/cantonese-romanization.js

A fully typed, general-purpose utility for unidirectional string transliteration (non-Latin script => Latin script).

import { getRoman } from "cantonese-romanisation";
const hanziRegex = /[\p{Script=Han}]/u;
export const romanizeCantonese = (input) => {
    let transliteration = "";
    let buffer = "";
    let lastWasHanzi = null;
    for (const char of input) {
        const isHanzi = hanziRegex.test(char);
        if (lastWasHanzi === null) {
            lastWasHanzi = isHanzi;
            buffer = char;
        }
        else if (isHanzi === lastWasHanzi) {
            buffer += char;
        }
        else {
            transliteration += lastWasHanzi
                ? getRoman(buffer)
                    .map((options) => options[0])
                    .join(" ")
                : buffer;
            buffer = char;
            lastWasHanzi = isHanzi;
        }
    }
    // Handle final buffer
    if (buffer) {
        transliteration += lastWasHanzi
            ? getRoman(buffer)
                .map((options) => options[0])
                .join(" ")
            : buffer;
    }
    return transliteration.replace(/\s+/g, " ").trim();
};