Ability to disable non-unicode patterns in format function

[patorjk]

Let's say I have an app that let's a user enter a date format and preview it: https://codesandbox.io/p/sandbox/date-fns-test-mlfc2n

And that format might be used by another app that uses Unicode Technical Standard 35. It would be nice if the format function had an option to disable the format additions listed in Note 7. I can do it by hand, but that wouldn't protect against any options that get added in the future.

[fturmel]

Interesting use case, and I think it could be done fairly simply.

Could be worth having the same mirror option to the parse function too.

Adding an option to FormatOptions (like useStandardUnicodeTokensOnly or disableNonStandardTokens), add an alternate formattingTokensRegExp for standard tokens only, and not matching the longFormattingTokensRegExp might be all we need?

date-fns/src/format/index.ts

Lines 35 to 40 in 5c1adb5

	const formattingTokensRegExp =
	/[yYQqMLwIdDecihHKkms]o|(\w)\1*|''|'(''|[^'])+('|$)|./g;
	// This RegExp catches symbols escaped by quotes, and also
	// sequences of symbols P, p, and the combinations like `PPPPPPPppppp`
	const longFormattingTokensRegExp = /P+p+|P+|p+|''|'(''|[^'])+('|$)|./g;