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948655e850
After rebasing on master and incorporating more 32-bit support, perform a bunch of cleanup, documentation updates, comments, move code back to String declaration, etc.
38 lines
1.3 KiB
Swift
38 lines
1.3 KiB
Swift
//===--- StringNormalization.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 - 2018 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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import SwiftShims
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internal enum _Normalization {
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// ICU's NFC unorm2 instance
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//
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// TODO(String performance): Should we cache one on TLS? Is this an expensive
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// call?
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internal static var _nfcNormalizer: OpaquePointer = {
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var err = __swift_stdlib_U_ZERO_ERROR
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let normalizer = __swift_stdlib_unorm2_getNFCInstance(&err)
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guard err.isSuccess else {
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// This shouldn't be possible unless some deep (unrecoverable) system
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// invariants are violated
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fatalError("Unable to talk to ICU")
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}
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return normalizer
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}()
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// When normalized in NFC, some segments may expand in size (e.g. some non-BMP
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// musical notes). This expansion is capped by the maximum expansion factor of
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// the normal form. For NFC, that is 3x.
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internal static let _maxNFCExpansionFactor = 3
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}
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