Update to Swift 5 (#210)

* Remove NewType wrapping Sequences and Collections, use *Wrapping instead

* Remove errant x

* Update Metatype: Hashable conformance to use Hasher

* Update Travis

* Try version 5.0

.travis.yml

@@ -4,11 +4,11 @@ os:
 language: generic
 sudo: required
 dist: trusty
-osx_image: xcode10
+osx_image: xcode10.2
 install:
   - eval "$(curl -sL https://swiftenv.fuller.li/install.sh)"
 env:
-  - SWIFT_VERSION=4.2
+  - SWIFT_VERSION=5.0
 script:
   - swift package update
   - swift test -c release

Sources/Algorithms/Combinatorics.swift

@@ -57,7 +57,7 @@ extension Collection {
 extension Sequence {
 
     /// - Returns: `Zip2Sequence` of 2-tuples composed of adjacent values.
-    public var pairs: Zip2Sequence<Self,SubSequence> {
+    public var pairs: Zip2Sequence<Self,DropFirstSequence<Self>> {
         return zip(self,dropFirst())
     }
 }

Sources/DataStructures/Matrix.swift

@@ -109,10 +109,11 @@ public struct Matrix <Element> {
     }
 }
 
-extension Matrix: CollectionWrapping {
+extension Matrix: SequenceWrapping {
 
-    // MARK: - CollectionWrapping
+    // MARK: - SequenceWrapping
 
+    /// - returns: Underlying `Collection`.
     public var base: [Element] {
         return grid
     }

Sources/DataStructures/Metatype.swift

@@ -42,7 +42,7 @@ extension Metatype: Hashable {
 
     /// - Returns: A unique hash value for the metatype wrapped-up herein.
     @inlinable
-    public var hashValue: Int {
-        return ObjectIdentifier(base).hashValue
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(ObjectIdentifier(base).hashValue)
     }
 }

Sources/DataStructures/NewType.swift

@@ -94,38 +94,3 @@ extension NewType where Value: Numeric {
 }
 
 extension NewType where Value: SignedNumeric { }
-
-extension NewType where Value: Sequence {
-    public func makeIterator() -> Value.Iterator {
-        return value.makeIterator()
-    }
-}
-
-extension NewType where Value: Collection {
-
-    public typealias Iterator = Value.Iterator
-
-    /// Start index.
-    public var startIndex: Value.Index {
-        return value.startIndex
-    }
-
-    /// End index.
-    public var endIndex: Value.Index {
-        return value.endIndex
-    }
-
-    /// Index after given index `i`.
-    public func index(after i: Value.Index) -> Value.Index {
-        return value.index(after: i)
-    }
-
-    public var indices: Value.Indices {
-        return value.indices
-    }
-
-    /// - returns: Element at the given `index`.
-    public subscript (index: Value.Index) -> Value.Element {
-        return value[index]
-    }
-}

Sources/DataStructures/Wrapping/SequenceWrapping.swift

@@ -21,34 +21,25 @@
 ///
 /// In the `init` method of the conforming `struct`, set the value of this private `var` with
 /// the given `sequence`.
-///
-/// - TODO: Consider removing `ExpressibleByArrayLiteral` and `init` requirements.
-public protocol SequenceWrapping: Sequence, ExpressibleByArrayLiteral {
+public protocol SequenceWrapping: Sequence {
 
     // MARK: Associated Types
 
-    // MARK: - Instance Properties
-
-    /// `AnySequence` wrapper that provides shade for the domain specific implementation.
-    var sequence: AnySequence<Element> { get }
+    /// Wrapped `Collection`-conforming type.
+    associatedtype Base: Sequence
 
-    // MARK: - Initializers
+    // MARK: - Instance Properties
 
-    /// Create an `SequenceWrapping` with a `Sequence`.
-    init <S> (_ sequence: S) where S: Sequence, S.Element == Element
+    /// Wrapped `Collection`-conforming type.
+    var base: Base { get }
 }
 
 extension SequenceWrapping {
 
     // MARK: - Sequence
 
     /// - returns a generator over the elements of this sequence.
-    public func makeIterator() -> AnyIterator<Element> {
-
-        let iterator = sequence.makeIterator()
-
-        return AnyIterator {
-            return iterator.next()
-        }
+    public func makeIterator() -> Base.Iterator {
+        return base.makeIterator()
     }
 }

Tests/DataStructuresTests/NewTypeTests.swift

@@ -42,16 +42,4 @@ class NewTypeTests: XCTestCase {
         let n: SN = 1
         let _ = -n
     }
-
-    func testSequence() {
-        struct S: NewType, Sequence { let value: [Int] }
-        let s = S([1,2,3])
-        let _ = s.map { $0 }
-    }
-
-    func testCollection() {
-        struct C: NewType, Collection { let value: [Int] }
-        let c = C([1,2,3])
-        let _ = c.count
-    }
 }

Tests/DataStructuresTests/XCTestManifests.swift

@@ -277,12 +277,10 @@ extension MutableGraphTests {
 
 extension NewTypeTests {
     static let __allTests = [
-        ("testCollection", testCollection),
         ("testComparable", testComparable),
         ("testExpressibleByFloatLiteral", testExpressibleByFloatLiteral),
         ("testExpressibleByIntegerLiteral", testExpressibleByIntegerLiteral),
         ("testNumeric", testNumeric),
-        ("testSequence", testSequence),
         ("testSignedNumeric", testSignedNumeric),
     ]
 }