77 lines
2.5 KiB
Swift
77 lines
2.5 KiB
Swift
//
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// Copyright (c) 2017 Touch Instinct
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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//
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public extension Array where Element: Equatable {
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/// Union array with another arrays, without element duplication
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func union(values: [Array.Element]...) -> Array {
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var result = self
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for array in values {
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for value in array {
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if !result.contains(value) {
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result.append(value)
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}
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}
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}
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return result
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}
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/// Find common elements among arrays
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func intersection(values: [Array.Element]...) -> Array {
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var result = self
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var intersection = Array()
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for (index, value) in values.enumerated() {
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if index > 0 {
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result = intersection
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intersection = Array()
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}
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value.forEach { item in
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if result.contains(item) && !intersection.contains(item) {
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intersection.append(item)
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}
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}
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}
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return intersection
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}
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/// Find unique elements in array compared to other arrays
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func subtract(values: [Array.Element]...) -> Array {
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let allValues = values.flatMap { $0 }
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return filter { !allValues.contains($0) }
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}
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}
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public extension Array {
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// Subscript for safe access to element by index
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subscript(safe index: Index) -> Element? {
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return (index < count && index >= 0) ? self[index] : nil
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}
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}
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