_ includeElement/whereElementsSatisfy predicate => _ isIncluded

Author: Dave Abrahams

stdlib/private/StdlibCollectionUnittest/LoggingWrappers.swift.gyb

@@ -229,10 +229,10 @@ public struct ${Self}<
   }
 
   public func filter(
-    _ includeElement: @noescape (Base.Iterator.Element) throws -> Bool
+    _ isIncluded: @noescape (Base.Iterator.Element) throws -> Bool
   ) rethrows -> [Base.Iterator.Element] {
     Log.filter[selfType] += 1
-    return try base.filter(includeElement)
+    return try base.filter(isIncluded)
   }
 
   public func forEach(

stdlib/public/core/ExistentialCollection.swift.gyb

@@ -147,7 +147,7 @@ internal class _AnyRandomAccessCollectionBox<Element>
   }
 
   internal func _filter(
-    _ includeElement: @noescape (Element) throws -> Bool
+    _ isIncluded: @noescape (Element) throws -> Bool
   ) rethrows -> [Element] {
     _abstract()
   }
@@ -335,9 +335,9 @@ internal final class _${Kind}Box<S : ${Kind}> : _Any${Kind}Box<S.Iterator.Elemen
     return try _base.map(transform)
   }
   internal override func _filter(
-    _ includeElement: @noescape (Element) throws -> Bool
+    _ isIncluded: @noescape (Element) throws -> Bool
   ) rethrows -> [Element] {
-    return try _base.filter(includeElement)
+    return try _base.filter(isIncluded)
   }
   internal override func _forEach(
     _ body: @noescape (Element) throws -> Void
@@ -579,9 +579,9 @@ extension Any${Kind} {
   }
 
   public func filter(
-    _ includeElement: @noescape (Element) throws -> Bool
+    _ isIncluded: @noescape (Element) throws -> Bool
   ) rethrows -> [Element] {
-    return try _box._filter(includeElement)
+    return try _box._filter(isIncluded)
   }
 
   public func forEach(

stdlib/public/core/Filter.swift.gyb

@@ -43,13 +43,13 @@ public struct LazyFilterIterator<
   }
 
   /// Creates an instance that produces the elements `x` of `base`
-  /// for which `predicate(x) == true`.
+  /// for which `isIncluded(x) == true`.
   internal init(
     _base: Base,
-    whereElementsSatisfy predicate: (Base.Element) -> Bool
+    _ isIncluded: (Base.Element) -> Bool
   ) {
     self._base = _base
-    self._predicate = predicate
+    self._predicate = isIncluded
   }
 
   /// The underlying iterator whose elements are being filtered.
@@ -75,18 +75,18 @@ public struct LazyFilterSequence<Base : Sequence>
   /// - Complexity: O(1).
   public func makeIterator() -> LazyFilterIterator<Base.Iterator> {
     return LazyFilterIterator(
-      _base: base.makeIterator(), whereElementsSatisfy: _include)
+      _base: base.makeIterator(), _include)
   }
 
   /// Creates an instance consisting of the elements `x` of `base` for
-  /// which `predicate(x) == true`.
+  /// which `isIncluded(x) == true`.
   public // @testable
   init(
     _base base: Base,
-    whereElementsSatisfy predicate: (Base.Iterator.Element) -> Bool
+    _ isIncluded: (Base.Iterator.Element) -> Bool
   ) {
     self.base = base
-    self._include = predicate
+    self._include = isIncluded
   }
 
   /// The underlying sequence whose elements are being filtered
@@ -186,14 +186,14 @@ public struct ${Self}<
   public typealias IndexDistance = Base.IndexDistance
 
   /// Construct an instance containing the elements of `base` that
-  /// satisfy `predicate`.
+  /// satisfy `isIncluded`.
   public // @testable
   init(
     _base: Base,
-    whereElementsSatisfy predicate: (Base.Iterator.Element) -> Bool
+    _ isIncluded: (Base.Iterator.Element) -> Bool
   ) {
     self._base = _base
-    self._predicate = predicate
+    self._predicate = isIncluded
   }
 
   /// The position of the first element in a non-empty collection.
@@ -281,7 +281,7 @@ public struct ${Self}<
   /// - Complexity: O(1).
   public func makeIterator() -> LazyFilterIterator<Base.Iterator> {
     return LazyFilterIterator(
-      _base: _base.makeIterator(), whereElementsSatisfy: _predicate)
+      _base: _base.makeIterator(), _predicate)
   }
 
   var _base: Base
@@ -291,17 +291,17 @@ public struct ${Self}<
 % end
 
 extension LazySequenceProtocol {
-  /// Returns the elements of `self` that satisfy `predicate`.
+  /// Returns the elements of `self` that satisfy `isIncluded`.
   ///
   /// - Note: The elements of the result are computed on-demand, as
   ///   the result is used. No buffering storage is allocated and each
   ///   traversal step invokes `predicate` on one or more underlying
   ///   elements.
   public func filter(
-    _ predicate: (Elements.Iterator.Element) -> Bool
+    _ isIncluded: (Elements.Iterator.Element) -> Bool
   ) -> LazyFilterSequence<Self.Elements> {
     return LazyFilterSequence(
-      _base: self.elements, whereElementsSatisfy: predicate)
+      _base: self.elements, isIncluded)
   }
 }
 
@@ -319,10 +319,10 @@ extension LazyCollectionProtocol
   ///   traversal step invokes `predicate` on one or more underlying
   ///   elements.
   public func filter(
-    _ predicate: (Elements.Iterator.Element) -> Bool
+    _ isIncluded: (Elements.Iterator.Element) -> Bool
   ) -> LazyFilter${collectionForTraversal(Traversal)}<Self.Elements> {
     return LazyFilter${collectionForTraversal(Traversal)}(
-      _base: self.elements, whereElementsSatisfy: predicate)
+      _base: self.elements, isIncluded)
   }
 }
 

stdlib/public/core/Sequence.swift

@@ -387,12 +387,12 @@ public protocol Sequence {
   ///     print(shortNames)
   ///     // Prints "["Kim", "Karl"]"
   ///
-  /// - Parameter includeElement: A closure that takes an element of the
+  /// - Parameter isIncluded: A closure that takes an element of the
   ///   sequence as its argument and returns a Boolean value indicating
   ///   whether the element should be included in the returned array.
   /// - Returns: An array of the elements that `includeElement` allowed.
   func filter(
-    _ includeElement: @noescape (Iterator.Element) throws -> Bool
+    _ isIncluded: @noescape (Iterator.Element) throws -> Bool
   ) rethrows -> [Iterator.Element]
 
   /// Calls the given closure on each element in the sequence in the same order
@@ -747,20 +747,20 @@ extension Sequence {
   ///     print(shortNames)
   ///     // Prints "["Kim", "Karl"]"
   ///
-  /// - Parameter includeElement: A closure that takes an element of the
+  /// - Parameter shouldInclude: A closure that takes an element of the
   ///   sequence as its argument and returns a Boolean value indicating
   ///   whether the element should be included in the returned array.
   /// - Returns: An array of the elements that `includeElement` allowed.
   public func filter(
-    _ includeElement: @noescape (Iterator.Element) throws -> Bool
+    _ isIncluded: @noescape (Iterator.Element) throws -> Bool
   ) rethrows -> [Iterator.Element] {
 
     var result = ContiguousArray<Iterator.Element>()
 
     var iterator = self.makeIterator()
 
     while let element = iterator.next() {
-      if try includeElement(element) {
+      if try isIncluded(element) {
         result.append(element)
       }
     }

stdlib/public/core/SequenceWrapper.swift

@@ -88,9 +88,9 @@ extension Sequence
   ///   whether the element should be included in the returned array.
   /// - Returns: An array of the elements that `includeElement` allowed.
   public func filter(
-    _ includeElement: @noescape (Base.Iterator.Element) throws -> Bool
+    _ isIncluded: @noescape (Base.Iterator.Element) throws -> Bool
   ) rethrows -> [Base.Iterator.Element] {
-    return try _base.filter(includeElement)
+    return try _base.filter(isIncluded)
   }
 
   public func _customContainsEquatableElement(

test/Prototypes/CollectionTransformers.swift

@@ -859,7 +859,7 @@ internal class _CollectionTransformerStep<PipelineInputElement_, OutputElement_>
     fatalError("abstract method")
   }
 
-  func filter(_ predicate: (OutputElement) -> Bool)
+  func filter(_ isIncluded: (OutputElement) -> Bool)
     -> _CollectionTransformerStep<PipelineInputElement, OutputElement> {
 
     fatalError("abstract method")
@@ -911,11 +911,11 @@ final internal class _CollectionTransformerStepCollectionSource<
     }
   }
 
-  override func filter(_ predicate: (InputElement) -> Bool)
+  override func filter(_ isIncluded: (InputElement) -> Bool)
     -> _CollectionTransformerStep<PipelineInputElement, InputElement> {
 
     return _CollectionTransformerStepOneToMaybeOne(self) {
-      predicate($0) ? $0 : nil
+      isIncluded($0) ? $0 : nil
     }
   }
 
@@ -990,15 +990,15 @@ final internal class _CollectionTransformerStepOneToMaybeOne<
     }
   }
 
-  override func filter(_ predicate: (OutputElement) -> Bool)
+  override func filter(_ isIncluded: (OutputElement) -> Bool)
     -> _CollectionTransformerStep<PipelineInputElement, OutputElement> {
 
     // Let the closure below capture only one variable, not the whole `self`.
     let localTransform = _transform
     return _CollectionTransformerStepOneToMaybeOne<PipelineInputElement, OutputElement, InputStep>(_input) {
       (input: InputElement) -> OutputElement? in
       if let e = localTransform(input) {
-        return predicate(e) ? e : nil
+        return isIncluded(e) ? e : nil
       }
       return nil
     }
@@ -1265,12 +1265,12 @@ public struct CollectionTransformerPipeline<
     )
   }
 
-  public func filter(_ predicate: (T) -> Bool)
+  public func filter(_ isIncluded: (T) -> Bool)
     -> CollectionTransformerPipeline<InputCollection, T> {
 
     return CollectionTransformerPipeline<InputCollection, T>(
       _input: _input,
-      _step: _step.filter(predicate)
+      _step: _step.filter(isIncluded)
     )
   }
 

validation-test/compiler_crashers_2_fixed/0020-rdar21598514.swift

@@ -116,10 +116,10 @@ extension LoggingSequenceType {
   }
 
   public func filter(
-    @noescape includeElement: (Base.Iterator.Element) -> Bool
+    @noescape isIncluded: (Base.Iterator.Element) -> Bool
   ) -> [Base.Iterator.Element] {
     ++SequenceLog.filter[selfType]
-    return base.filter(includeElement)
+    return base.filter(isIncluded)
   }
 
   public func _customContainsEquatableElement(

validation-test/compiler_crashers_2_fixed/0022-rdar21625478.swift

@@ -24,7 +24,7 @@ public protocol MySequence {
   ) -> [T]
 
   func filter(
-    _ includeElement: @noescape (Iterator.Element) -> Bool
+    _ isIncluded: @noescape (Iterator.Element) -> Bool
   ) -> [Iterator.Element]
 
   func _customContainsEquatableElement(
@@ -54,7 +54,7 @@ extension MySequence {
   }
 
   public func filter(
-    _ includeElement: @noescape (Iterator.Element) -> Bool
+    _ isIncluded: @noescape (Iterator.Element) -> Bool
   ) -> [Iterator.Element] {
     return []
   }
@@ -256,10 +256,10 @@ extension LoggingSequenceType
   }
 
   public func filter(
-    _ includeElement: @noescape (Base.Iterator.Element) -> Bool
+    _ isIncluded: @noescape (Base.Iterator.Element) -> Bool
   ) -> [Base.Iterator.Element] {
     Log.filter[selfType] += 1
-    return base.filter(includeElement)
+    return base.filter(isIncluded)
   }
 
   public func _customContainsEquatableElement(

validation-test/stdlib/CollectionType.swift.gyb

@@ -105,10 +105,10 @@ struct MinimalCollectionWith${Implementation}Filter<Element>
   }
 
   func filter(
-    _ transform: @noescape (Element) throws -> Bool
+    _ isIncluded: @noescape (Element) throws -> Bool
   ) rethrows -> [Element] {
     MinimalCollectionWithCustomFilter.timesFilterWasCalled += 1
-    return try _data.filter(transform)
+    return try _data.filter(isIncluded)
   }
 
 %   end
@@ -119,27 +119,27 @@ struct MinimalCollectionWith${Implementation}Filter<Element>
 
 func callStaticCollectionFilter(
   _ sequence: MinimalCollectionWithDefaultFilter<OpaqueValue<Int>>,
-  includeElement: @noescape (OpaqueValue<Int>) -> Bool
+  _ isIncluded: @noescape (OpaqueValue<Int>) -> Bool
 ) -> [OpaqueValue<Int>] {
-  var result = sequence.filter(includeElement)
+  var result = sequence.filter(isIncluded)
   expectType([OpaqueValue<Int>].self, &result)
   return result
 }
 
 func callStaticCollectionFilter(
   _ sequence: MinimalCollectionWithCustomFilter<OpaqueValue<Int>>,
-  includeElement: @noescape (OpaqueValue<Int>) -> Bool
+  _ isIncluded: @noescape (OpaqueValue<Int>) -> Bool
 ) -> [OpaqueValue<Int>] {
-  var result = sequence.filter(includeElement)
+  var result = sequence.filter(isIncluded)
   expectType([OpaqueValue<Int>].self, &result)
   return result
 }
 
 func callGenericCollectionFilter<S : Collection>(
   _ sequence: S,
-  includeElement: @noescape (S.Iterator.Element) -> Bool
+  _ isIncluded: @noescape (S.Iterator.Element) -> Bool
 ) -> [S.Iterator.Element] {
-  var result = sequence.filter(includeElement)
+  var result = sequence.filter(isIncluded)
   expectType(Array<S.Iterator.Element>.self, &result)
   return result
 }

validation-test/stdlib/Lazy.swift.gyb

@@ -1057,7 +1057,7 @@ tests.test("LazyFilterSequence") {
   // Try again using explicit construction
   filtered = LazyFilterSequence(
     _base: MinimalSequence(elements: base),
-    whereElementsSatisfy: { x in calls += 1; return x.value % 2 == 0})
+    { x in calls += 1; return x.value % 2 == 0})
 
   expectEqual(100, calls)