Files
swift-mirror/stdlib/public/core/UnicodeEncoding.swift
Dave Abrahams feea061d32 [stdlib] Move new Unicode decoders into the stdlib
No expected change in benchmarks, as legacy components aren't using this yet.
2017-05-01 17:08:08 -07:00

50 lines
2.0 KiB
Swift

//===--- UnicodeEncoding.swift --------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
public protocol _UnicodeEncoding {
/// The basic unit of encoding
associatedtype CodeUnit : UnsignedInteger, FixedWidthInteger
/// A valid scalar value as represented in this encoding
associatedtype EncodedScalar : BidirectionalCollection
where EncodedScalar.Iterator.Element == CodeUnit
/// The replacement character U+FFFD as represented in this encoding
static var encodedReplacementCharacter : EncodedScalar { get }
/// Converts from encoded to encoding-independent representation
static func decode(_ content: EncodedScalar) -> UnicodeScalar
/// Converts from encoding-independent to encoded representation
static func encode(_ content: UnicodeScalar) -> EncodedScalar
associatedtype ForwardParser : UnicodeParser
associatedtype ReverseParser : UnicodeParser
//===--------------------------------------------------------------------===//
// FIXME: this requirement shouldn't be here and is mitigated by the default
// implementation below. Compiler bugs prevent it from being expressed in an
// intermediate, underscored protocol.
/// Returns true if `x` only appears in this encoding as the representation of
/// a complete scalar value.
static func _isScalar(_ x: CodeUnit) -> Bool
}
extension _UnicodeEncoding {
// See note on declaration of requirement, above
public static func _isScalar(_ x: CodeUnit) -> Bool { return false }
}
public protocol UnicodeEncoding : _UnicodeEncoding
where ForwardParser.Encoding == Self, ReverseParser.Encoding == Self {}