[Foundation] Add initializers for NSRange<-->Range #9709
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@swift-ci please test |
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@swift-ci please test source compatibility |
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| extension Range where Bound: BinaryInteger { |
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shouldn't we also do the other range types here too?
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Hmm, probably not. We don't generally encourage people to create the other range types without using the operators. Range is the currency type.
| public init<R: RangeExpression>(_ rangeExpression: R) | ||
| where R.Bound: FixedWidthInteger, R.Bound.Stride : SignedInteger { | ||
| let range = rangeExpression.relative(to: 0..<R.Bound.max) | ||
| let start: Int = numericCast(range.lowerBound) |
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so what happens here when you have a 32 bit host and the passed in range is a UInt64 that exceeds Int32.max?
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It would trap – expectedly. To construct an NSRange you need an Int. The alternative is we only allow construction from RangeExpressions of Int and push the casting onto the caller. I'm kind of ambivalent which.
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eh as is seems fine; I just wanted to make sure it wasn't some funky bit truncation. Trap seems quite reasonable.
| extension Range where Bound == Int { | ||
| public init?(_ range: NSRange) { | ||
| guard range.location != NSNotFound else { return nil } | ||
| self = range.lowerBound..<range.upperBound |
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@swift-ci please smoke test and merge |
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@swift-ci please smoke test |
* Add initializers to NSRange/Range * Create Ranges unchecked
Allows conversion between
Swift.RangeandNSRangefor integers and strings.