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oleole
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Merge pull request #1 from klaaspieter/remove
Complete set of removal methods for SortedArray
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‎Sources/SortedArray.swift

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@@ -116,6 +116,115 @@ extension SortedArray: CustomStringConvertible, CustomDebugStringConvertible {
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}
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}
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// MARK: - Removing elements. This is mostly a reimplementation of part `RangeReplaceableCollection`'s interface. `SortedArray` can't conform to `RangeReplaceableCollection` because some of that protocol's semantics (e.g. `append(_:)` don't fit `SortedArray`'s semantics.
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extension SortedArray {
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/// Removes and returns the element at the specified position.
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///
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/// - Parameter index: The position of the element to remove. `index` must be a valid index of the array.
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/// - Returns: The element at the specified index.
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func remove(at index: Int) -> Element {
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return _elements.remove(at: index)
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}
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/// Removes the elements in the specified subrange from the array.
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///
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/// - Parameter bounds: The range of the array to be removed. The
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/// bounds of the range must be valid indices of the array.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeSubrange(_ bounds: Range<Int>) {
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_elements.removeSubrange(bounds)
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}
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/// Removes the elements in the specified subrange from the array.
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///
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/// - Parameter bounds: The range of the array to be removed. The
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/// bounds of the range must be valid indices of the array.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeSubrange(_ bounds: ClosedRange<Int>) {
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_elements.removeSubrange(bounds)
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}
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/// Removes the elements in the specified subrange from the array.
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///
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/// - Parameter bounds: The range of the array to be removed. The
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/// bounds of the range must be valid indices of the array.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeSubrange(_ bounds: CountableRange<Int>) {
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_elements.removeSubrange(bounds)
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}
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/// Removes the elements in the specified subrange from the array.
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///
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/// - Parameter bounds: The range of the array to be removed. The
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/// bounds of the range must be valid indices of the array.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeSubrange(_ bounds: CountableClosedRange<Int>) {
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_elements.removeSubrange(bounds)
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}
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/// Removes the specified number of elements from the beginning of the
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/// array.
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///
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/// - Parameter n: The number of elements to remove from the array.
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/// `n` must be greater than or equal to zero and must not exceed the
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/// number of elements in the array.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeFirst(_ n: Int) {
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_elements.removeFirst(n)
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}
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/// Removes and returns the first element of the array.
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///
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/// - Precondition: The array must not be empty.
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/// - Returns: The removed element.
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/// - Complexity: O(_n_), where _n_ is the length of the collection.
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public mutating func removeFirst() -> Element {
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return _elements.removeFirst()
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}
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/// Removes and returns the last element of the array.
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///
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/// - Precondition: The collection must not be empty.
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/// - Returns: The last element of the collection.
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/// - Complexity: O(1)
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public mutating func removeLast() -> Element {
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return _elements.removeLast()
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}
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/// Removes the given number of elements from the end of the array.
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///
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/// - Parameter n: The number of elements to remove. `n` must be greater
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/// than or equal to zero, and must be less than or equal to the number of
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/// elements in the array.
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/// - Complexity: O(1).
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public mutating func removeLast(_ n: Int) {
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_elements.removeLast(n)
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}
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/// Removes all elements from the array.
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///
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/// - Parameter keepCapacity: Pass `true` to keep the existing capacity of the array after removing its elements. The default value is `false`.
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///
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/// - Complexity: O(_n_), where _n_ is the length of the array.
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public mutating func removeAll(keepingCapacity keepCapacity: Bool = true) {
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_elements.removeAll(keepingCapacity: keepCapacity)
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}
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/// Removes an element from the array. If the array contains multiple instances of `element`, this method only removes the first one.
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///
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/// - Complexity: O(_n_), where _n_ is the size of the array.
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public mutating func remove(_ element: Element) {
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guard let index = index(of: element) else { return }
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_elements.remove(at: index)
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}
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}
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// MARK: - More efficient variants of default implementations or implementations that need fewer constraints than the default implementations.
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extension SortedArray {
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/// Returns the first index where the specified value appears in the collection.

‎Tests/SortedArrayTests/SortedArrayTests.swift

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@@ -152,17 +152,73 @@ class SortedArrayTests: XCTestCase {
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XCTAssertEqual(description, "<SortedArray> [\"a\", \"b\", \"c\"]")
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}
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func testFilterReturnsSortedArray() {
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let source = SortedArray(unsorted: [3,2,1])
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let sut = source.filter { $0 % 2 == 0 }
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XCTAssert(type(of: sut) == SortedArray<Int>.self)
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func testFilter() {
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let sut = SortedArray(unsorted: ["a", "b", "c"])
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assertElementsEqual(sut.filter { $0 != "a" }, ["b", "c"])
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}
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func testFilterMaintainsSortOrder() {
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let sut = SortedArray(unsorted: ["b", "a", "c", "a", "d", "A"])
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assertElementsEqual(sut.filter { $0 != "a" }, ["A", "b", "c", "d"])
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func testRemoveAtIndex() {
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var sut = SortedArray(unsorted: [3,4,2,1])
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let removedElement = sut.remove(at: 1)
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assertElementsEqual(sut, [1,3,4])
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XCTAssertEqual(removedElement, 2)
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}
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func testRemoveSubrange() {
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var sut = SortedArray(unsorted: ["a","d","c","b"])
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sut.removeSubrange(2..<4)
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assertElementsEqual(sut, ["a","b"])
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}
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func testRemoveFirst() {
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var sut = SortedArray(unsorted: [3,4,2,1])
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let removedElement = sut.removeFirst()
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assertElementsEqual(sut, [2,3,4])
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XCTAssertEqual(removedElement, 1)
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}
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func testRemoveFirstN() {
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var sut = SortedArray(unsorted: [3,4,2,1])
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sut.removeFirst(2)
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assertElementsEqual(sut, [3,4])
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}
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func testRemoveLast() {
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var sut = SortedArray(unsorted: [3,4,2,1])
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let removedElement = sut.removeLast()
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assertElementsEqual(sut, [1,2,3])
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XCTAssertEqual(removedElement, 4)
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}
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func testRemoveLastN() {
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var sut = SortedArray(unsorted: [3,4,2,1])
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sut.removeLast(2)
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assertElementsEqual(sut, [1,2])
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}
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func testRemoveAll() {
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var sut = SortedArray(unsorted: ["a","d","c","b"])
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sut.removeAll()
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assertElementsEqual(sut, [])
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}
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func testRemoveElementAtBeginningPreservesSortOrder() {
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var sut = SortedArray(unsorted: 1...3)
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sut.remove(1)
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assertElementsEqual(sut, [2,3])
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}
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func testRemoveElementInMiddlePreservesSortOrder() {
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var sut = SortedArray(unsorted: 1...5)
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sut.remove(4)
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assertElementsEqual(sut, [1,2,3,5])
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}
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func testRemoveElementAtEndPreservesSortOrder() {
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var sut = SortedArray(unsorted: 1...3)
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sut.remove(3)
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assertElementsEqual(sut, [1,2])
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}
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}
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extension SortedArrayTests {
@@ -191,8 +247,17 @@ extension SortedArrayTests {
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("testMax", testMax),
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("testCustomStringConvertible", testCustomStringConvertible),
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("testCustomDebugStringConvertible", testCustomDebugStringConvertible),
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("testFilterReturnsSortedArray", testFilterReturnsSortedArray),
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("testFilterMaintainsSortOrder", testFilterMaintainsSortOrder),
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("testFilter", testFilter),
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("testRemoveAtIndex", testRemoveAtIndex),
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("testRemoveSubrange", testRemoveSubrange),
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("testRemoveFirst", testRemoveFirst),
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("testRemoveFirstN", testRemoveFirstN),
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("testRemoveLast", testRemoveLast),
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("testRemoveLastN", testRemoveLastN),
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("testRemoveAll", testRemoveAll),
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("testRemoveElementAtBeginningPreservesSortOrder", testRemoveElementAtBeginningPreservesSortOrder),
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("testRemoveElementInMiddlePreservesSortOrder", testRemoveElementInMiddlePreservesSortOrder),
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("testRemoveElementAtEndPreservesSortOrder", testRemoveElementAtEndPreservesSortOrder),
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]
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}
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}

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