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And make RandomAccessIndex refine it. * had to XFAIL test/Prototypes/TextFormatting.swift (<rdar://problem/17619178>) * Had to compromise on the name of Strideable's associated type (<rdar://problem/17619038>) Swift SVN r19785
42 lines
1.2 KiB
Swift
42 lines
1.2 KiB
Swift
//===--- Stride.swift - Components for stride(...) iteration --------------===//
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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 - 2015 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 http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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//
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//
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//===----------------------------------------------------------------------===//
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public protocol Strideable {
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// FIXME: We'd like to name this type "DistanceType" but for
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// <rdar://problem/17619038>
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typealias Stride : SignedNumber
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func distanceTo(Self) -> Stride
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func advancedBy(Stride) -> Self
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}
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public func + <T: Strideable> (lhs: T, rhs: T.Stride) -> T {
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return lhs.advancedBy(rhs)
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}
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public func + <T: Strideable> (lhs: T.Stride, rhs: T) -> T {
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return rhs.advancedBy(lhs)
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}
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public func - <T: Strideable> (lhs: T, rhs: T.Stride) -> T {
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return lhs.advancedBy(-rhs)
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}
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public func - <T: Strideable> (lhs: T, rhs: T) -> T.Stride {
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return rhs.distanceTo(lhs)
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}
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