Throw an error if options cannot be applied instead of silently ignoring them? about proposal-intl-locale

[anba]

I should have probably mentioned that I don't have a strong opinion here. I just felt it make sense to raise this issue while this proposal is still in the making.

[srl295]

new Intl.Locale("x-private", {language: "en"}).toString() could just return en because you're replacing the language. More concerning would be trying to set a calendar on top of x-private because that won't work.

Perhaps it would be helpful to have isPrivateUse() and/or isGrandfathered() predicates pursuant to https://tools.ietf.org/html/bcp47#section-2.2.1 ?

A better worse case is new Intl.Locale("x-private", {script: "Adlm"}).toString(), that might be the time to throw.

[littledan]

@srl295 Do you have an idea of a particular case where you'd want to do new Intl.Locale("x-private", {language: "en"})? This will be possible to specify, but it makes things somewhat more complicated than if we just throw an exception.

[srl295]

I don't have a case. It's just the sense of "I want to set the language but leave everything else alone"

[littledan]

OK, #50 does those semantics. It didn't end up being as complicated as I feared.