Add LazySequenceProtocol to StridingSequence, StridingCollection

Author: Tim Vermeulen

Sources/Algorithms/Stride.swift

@@ -112,6 +112,9 @@ extension StridingSequence: Sequence {
   }
 }
 
+extension StridingSequence: LazySequenceProtocol
+  where Base: LazySequenceProtocol {}
+
 /// A wrapper that strides over a base collection.
 public struct StridingCollection<Base: Collection> {
   @usableFromInline
@@ -273,4 +276,8 @@ extension StridingCollection: BidirectionalCollection
 
 extension StridingCollection: RandomAccessCollection
   where Base: RandomAccessCollection {}
+
+extension StridingCollection: LazySequenceProtocol, LazyCollectionProtocol
+  where Base: LazySequenceProtocol {}
+
 extension StridingCollection.Index: Hashable where Base.Index: Hashable {}

Tests/SwiftAlgorithmsTests/StrideTests.swift

@@ -119,7 +119,6 @@ final class StridingTests: XCTestCase {
       validator.validate(string.striding(by: 10))
     }
   }
-
 
   func testOffsetBy() {
     let a = (0...100).striding(by: 22)
@@ -135,4 +134,10 @@ final class StridingTests: XCTestCase {
     let i = b.index(b.startIndex, offsetBy: 2)
     XCTAssertEqual(i, b.endIndex)
   }
+  
+  func testLazy() {
+    XCTAssertLazySequence(AnySequence(0..<100).lazy.striding(by: 3))
+    XCTAssertLazySequence((0..<100).lazy.striding(by: 3))
+    XCTAssertLazyCollection((0..<100).lazy.striding(by: 3))
+  }
 }