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A comment on A popular but wrong way to convert a string to uppercase or lowercase. Parent comment

Re:A popular but wrong way to convert a string to uppercase ... by kccqzy on Tuesday October 08, 2024 @03:04PM (#41780647)
Still breaks on, for example, Turkish i vs İ. It's impossible to do correctly without language information.

> (No, Python can't turn 'SS' back into 'ß'. But doing that requires metadata about language that a string simply doesn't represent.)

Yes that's my point. Because in typical languages strings don't store language metadata, this is impossible to do correctly in general.

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Re:A popular but wrong way to convert a string to uppercase ... by zahlman on Tuesday October 08, 2024 @03:08PM (#41780685)
I'm not seeing anything in the Swift documentation about strings carrying language metadata, either, though?
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Re:A popular but wrong way to convert a string to uppercase ... by kccqzy on Tuesday October 08, 2024 @03:20PM (#41780805)
This lowercase function takes a locale argument https://developer.apple.com/documentation/foundation/nsstrin...

It looks like an old NSString method that's available in both Obj-C and Swift.

The casefold function is even older than that. https://developer.apple.com/documentation/foundation/nsstrin... Its documentation specifically includes a discussion of the Turkish İ/I issue.

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