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4ab45dfe20
This is a giant squashing of a lot of individual changes prototyping a switch of String in Swift 5 to be natively encoded as UTF-8. It includes what's necessary for a functional prototype, dropping some history, but still leaves plenty of history available for future commits. My apologies to anyone trying to do code archeology between this commit and the one prior. This was the lesser of evils.
76 lines
2.0 KiB
Swift
76 lines
2.0 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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// Declarations to enable ease-of-testing
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public // @testable
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struct _StringRepresentation {
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public var _isASCII: Bool
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public var _count: Int
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public var _capacity: Int
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public enum _Form {
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case _small
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case _cocoa(object: AnyObject)
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case _native(object: AnyObject)
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case _immortal(address: UInt)
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// TODO: shared native
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}
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public var _form: _Form
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public var _objectIdentifier: ObjectIdentifier? {
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switch _form {
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case ._cocoa(let object): return ObjectIdentifier(object)
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case ._native(let object): return ObjectIdentifier(object)
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default: return nil
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}
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}
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}
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extension String {
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public // @testable
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func _classify() -> _StringRepresentation { return _guts._classify() }
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}
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extension _StringGuts {
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internal func _classify() -> _StringRepresentation {
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var result = _StringRepresentation(
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_isASCII: self.isKnownASCII,
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_count: self.count,
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_capacity: self.capacity ?? 0,
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_form: ._small
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)
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if _object.isSmall {
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return result
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}
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if _object.largeIsCocoa {
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result._form = ._cocoa(object: _object.cocoaObject)
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return result
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}
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// TODO: shared native
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_sanityCheck(_object.providesFastUTF8)
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_sanityCheck(_object.largeFastIsNative)
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if _object.isImmortal {
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result._form = ._immortal(
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address: UInt(bitPattern: _object.nativeUTF8Start))
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return result
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}
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if _object.hasNativeStorage {
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result._form = ._native(object: _object.nativeStorage)
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return result
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}
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fatalError()
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}
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}
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