Language hint

Some languages have overlapping characters. To provide the most accurate result, we could accept a language hint and prefer that language when there’s a conflict. You would still be able to use multiple languages in a string, but the provided one gets priority. For example, sv-SE to prioritize the Swedish replacement.

[dotnetCarpenter]

BCP-47 is used in most places currently, from Accept-language in HTTP, to lang in HTML, to i18n features in ECMAScript’s locale support.

I could get behind BCP-47 for the sole reason that it is familiar. But also more granular than a language code.

[Mottie]

We started building something similar to this a few years ago - https://github.com/diacritics - but we never finished it.

We had the transliteration default to general usage, but also allowed the user set the language and variant. For example:

const transliterate = require("diacritics-transliterator").transliterate;

const german = transliterate("¿abcñ-ß123?", "decompose", "de");
/* german => "¿abcñ-ss123?"; only the German s-sharp is replaced */

const spanish = transliterate("¿abcñ-ß123?", "base", "es");
/* spanish => "?abcn-ß123?"; only the Spanish ñ is modified */

const generic = transliterate("¿abcñ-ß123?");
/* generic => "?abcn-ß123?"; the base of ß is still ß */

const unchanged = transliterate("¿abcñ-ß123?", "base", "test");
/* unchanged => "¿abcñ-ß123?"; if no diacritics match the set language variant,
  the original string is returned */

But, that might have been too aggressive because the code owner opted to rewrite the transliterater to be much more basic.