Intl Parse Number

intlParse.ts

// https://observablehq.com/@mbostock/localized-number-parsing

const makeIntlParse = (locale: string) => {
    const parts = new Map(new Intl.NumberFormat(locale).formatToParts(12345.6).map((part) => [part.type, part.value]));
    const numerals = Array.from(new Intl.NumberFormat(locale, { useGrouping: false }).format(9876543210)).reverse();
    const index = new Map(numerals.map((d, i) => [d, i]));

    const reGroup = new RegExp(`[${parts.get("group")}]`, "g");
    const reDecimal = new RegExp(`[${parts.get("decimal")}]`);
    const reNumeral = new RegExp(`[${numerals.join("")}]`, "g");

    return (str: string) => {
        const parsedStr = str
            .trim()
            .replace(reGroup, "")
            .replace(reDecimal, ".")
            .replace(reNumeral, (d) => `${index.get(d)}`);

        return parseFloat(parsedStr);
    };
};

[
    ["fr", "12 345 678,9"],
    ["en", "12,345,678.90"],
    ["de", "12.345.678,90"],
    ["ar-EG", "١٢٬٣٤٥٬٦٧٨٫٩٠"],
].map(([locale, str]) => {
    const parse = makeIntlParse(locale);
    const result = parse(str);

    console.log("locale: %s, str: %s, result: %f", locale, str, result);
});