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99 lines
3.0 KiB
Plaintext
99 lines
3.0 KiB
Plaintext
//===--- CollectionAlgorithms.swift.gyb -----------------------------------===//
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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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# We know we will eventually get a SequenceType.Element type. Define
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# a shorthand that we can use today.
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GElement = "Generator.Element"
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}%
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//===----------------------------------------------------------------------===//
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// isEmpty
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//===----------------------------------------------------------------------===//
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extension CollectionType {
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/// Returns `true` iff `self` is empty.
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final public var _prext_isEmpty: Bool {
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// FIXME: dynamic dispatch for Set and Dictionary.
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return startIndex == endIndex
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}
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}
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//===----------------------------------------------------------------------===//
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// first
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//===----------------------------------------------------------------------===//
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extension CollectionType {
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/// Returns the first element of `self`, or `nil` if `self` is empty.
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final public var _prext_first: Generator.Element? {
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return _prext_isEmpty ? nil : self[startIndex]
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}
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}
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//===----------------------------------------------------------------------===//
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// find()
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//===----------------------------------------------------------------------===//
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extension CollectionType where Self.${GElement} : Equatable {
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/// Returns the first index where `value` appears in `self` or `nil` if
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/// `value` is not found.
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///
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/// Complexity: O(\ `self.count()`\ )
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final public func _prext_find(element: ${GElement}) -> Index? {
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if let result? = _customFindEquatableElement(element) {
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return result
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}
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for i in self._prext_indices {
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if self[i] == element {
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return i
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}
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}
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return nil
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}
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}
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extension CollectionType {
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/// Returns the first index where `predicate` returns `true` for the
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/// corresponding value, or `nil` if such value is not found.
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///
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/// Complexity: O(\ `self.count()`\ )
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final public func _prext_find(
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@noescape predicate: (${GElement}) -> Bool
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) -> Index? {
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for i in indices(self) {
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if predicate(self[i]) {
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return i
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}
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}
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return nil
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}
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}
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//===----------------------------------------------------------------------===//
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// indices()
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//===----------------------------------------------------------------------===//
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extension CollectionType {
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/// Return the range of valid index values.
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///
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/// The result's `endIndex` is the same as that of `self`. Because
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/// `Range` is half-open, iterating the values of the result produces
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/// all valid subscript arguments for `self`, omitting its `endIndex`.
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final public var _prext_indices: Range<Index> {
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return Range(start: startIndex, end: endIndex)
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}
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}
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