Remove Cased Unicode table
#146180
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Remove Cased Unicode table
#146180
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`Cased` is a derived property - it is the union of the `Lowercase` property, the `Uppercase` property, and the `Titlecase_Letter` general categories. We already have lookup tables for `Lowercase` and `Uppercase`, and `Titlecase_Letter` is very small. So instead of duplicating a lookup table for `Cased`, just test each of those properties in turn. This probably will be slower than the old approach, but it is not a public API: it is only used in `string::to_lower` when deciding when a Greek "sigma" should be mapped to `ς` or to `σ`. This is a very rare case, so should not be performance sensitive.
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Cased tableCased Unicode table
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Awaiting bors try build completion. @rustbot label: +S-waiting-on-perf |
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Remove `Cased` Unicode table
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Split off from #145219
Casedis a derived property - it is the union of theLowercaseproperty, theUppercaseproperty, and theTitlecase_Lettergeneral categories. We already have lookup tables forLowercaseandUppercase, andTitlecase_Letteris very small. So instead of duplicating a lookup table forCased, just test each of those properties in turn.This probably will be slower than the old approach, but it is not a public API: it is only used in
string::to_lowerwhen deciding when a Greek "sigma" should be mapped toςor toσ. This is a very rare case, so should not be performance sensitive.