stdlib: underscore AnyCollectionProtocol

Author: natecook1000

stdlib/public/core/ExistentialCollection.swift.gyb

@@ -715,28 +715,11 @@ public func < (lhs: AnyIndex, rhs: AnyIndex) -> Bool {
 //===--- Collections ------------------------------------------------------===//
 //===----------------------------------------------------------------------===//
 
-/// A protocol for `AnyCollection<Element>`,
-/// `AnyBidirectionalCollection<Element>`, and
-/// `AnyRandomAccessCollection<Element>`.
-public protocol AnyCollectionProtocol : Collection {
+public // @testable
+protocol _AnyCollectionProtocol : Collection {
   /// Identifies the underlying collection stored by `self`. Instances
-  /// copied from one another have the same `_underlyingCollectionID`.
-  var _underlyingCollectionID: ObjectIdentifier { get }
-
-  /// Returns `true` iff `self` and `other` use the same `_box` to store their
-  /// underlying collections.
-  func _storesSameUnderlyingCollection<
-    C: AnyCollectionProtocol
-  >(_ other: C) -> Bool
-}
-
-extension AnyCollectionProtocol {
-  public // @testable
-  func _storesSameUnderlyingCollection<
-    C: AnyCollectionProtocol
-  >(_ other: C) -> Bool {
-    return _underlyingCollectionID == other._underlyingCollectionID
-  }
+  /// copied or upgraded/downgraded from one another have the same `_boxID`.
+  var _boxID: ObjectIdentifier { get }
 }
 
 % for (ti, Traversal) in enumerate(TRAVERSALS):
@@ -751,7 +734,7 @@ extension AnyCollectionProtocol {
 ///
 /// - SeeAlso: ${', '.join('`Any%sCollection`' % t for t in (2 * TRAVERSALS)[ti + 1 : ti + 3]) }
 public struct ${Self}<Element>
-  : AnyCollectionProtocol, ${SelfProtocol} {
+  : _AnyCollectionProtocol, ${SelfProtocol} {
 
   internal init(_box: _${Self}Box<Element>) {
     self._box = _box
@@ -948,7 +931,7 @@ public struct ${Self}<Element>
 
   /// Uniquely identifies the stored underlying collection.
   public // Due to language limitations only
-  var _underlyingCollectionID: ObjectIdentifier {
+  var _boxID: ObjectIdentifier {
     return ObjectIdentifier(_box)
   }
 
@@ -976,10 +959,13 @@ extension Any${Kind} {
 }
 %end
 
-@available(*, unavailable, renamed: "AnyCollectionProtocol")
-public typealias AnyCollectionType = AnyCollectionProtocol
+@available(*, unavailable, renamed: "_AnyCollectionProtocol")
+public typealias AnyCollectionType = _AnyCollectionProtocol
+
+@available(*, unavailable, renamed: "_AnyCollectionProtocol")
+public typealias AnyCollectionProtocol = _AnyCollectionProtocol
 
-extension AnyCollectionProtocol {
+extension _AnyCollectionProtocol {
   @available(*, unavailable, renamed: "makeIterator()")
   public func generate() -> AnyIterator<Iterator.Element> {
     Builtin.unreachable()
@@ -1004,14 +990,14 @@ public func anyGenerator<Element>(_ body: () -> Element?) -> AnyIterator<Element
 
 @available(*, unavailable)
 public func === <
-  L : AnyCollectionProtocol, R : AnyCollectionProtocol
+  L : _AnyCollectionProtocol, R : _AnyCollectionProtocol
 >(lhs: L, rhs: R) -> Bool {
   Builtin.unreachable()
 }
 
 @available(*, unavailable)
 public func !== <
-  L : AnyCollectionProtocol, R : AnyCollectionProtocol
+  L : _AnyCollectionProtocol, R : _AnyCollectionProtocol
 >(lhs: L, rhs: R) -> Bool {
   Builtin.unreachable()
 }

validation-test/stdlib/ExistentialCollection.swift.gyb

@@ -57,6 +57,12 @@ extension AnyRandomAccessCollection where Element : TestProtocol1 {
   }
 }
 
+func storesSameUnderlyingCollection<
+  L: _AnyCollectionProtocol, R: _AnyCollectionProtocol
+>(_ lhs: L, _ rhs: R) -> Bool {
+  return lhs._boxID == rhs._boxID
+}
+
 var tests = TestSuite("ExistentialCollection")
 
 tests.test("AnyIterator") {
@@ -357,13 +363,13 @@ tests.test("BidirectionalCollection") {
   let bc0_ = AnyBidirectionalCollection(fc0)  // upgrade!
   expectNotEmpty(bc0_)
   let bc0 = bc0_!
-  expectTrue(fc0._storesSameUnderlyingCollection(bc0))
+  expectTrue(storesSameUnderlyingCollection(fc0, bc0))
 
   let fc1 = AnyCollection(a0.lazy.reversed()) // new collection
-  expectFalse(fc1._storesSameUnderlyingCollection(fc0))
+  expectFalse(storesSameUnderlyingCollection(fc1, fc0))
 
   let fc2 = AnyCollection(bc0)                // downgrade
-  expectTrue(fc2._storesSameUnderlyingCollection(bc0))
+  expectTrue(storesSameUnderlyingCollection(fc2, bc0))
 
   let a1 = ContiguousArray(bc0.lazy.reversed())
   expectEqual(a0, a1)
@@ -381,7 +387,7 @@ tests.test("BidirectionalCollection") {
   let s0 = "Hello, Woyld".characters
   let bc1 = AnyBidirectionalCollection(s0)
   let fc3 = AnyCollection(bc1)
-  expectTrue(fc3._storesSameUnderlyingCollection(bc1))
+  expectTrue(storesSameUnderlyingCollection(fc3, bc1))
   expectEmpty(AnyRandomAccessCollection(bc1))
   expectEmpty(AnyRandomAccessCollection(fc3))
 }
@@ -392,13 +398,13 @@ tests.test("RandomAccessCollection") {
   let rc0_ = AnyRandomAccessCollection(fc0)         // upgrade!
   expectNotEmpty(rc0_)
   let rc0 = rc0_!
-  expectTrue(rc0._storesSameUnderlyingCollection(fc0))
+  expectTrue(storesSameUnderlyingCollection(rc0, fc0))
 
   let bc1 = AnyBidirectionalCollection(rc0)         // downgrade
-  expectTrue(bc1._storesSameUnderlyingCollection(rc0))
+  expectTrue(storesSameUnderlyingCollection(bc1, rc0))
 
   let fc1 = AnyBidirectionalCollection(rc0)         // downgrade
-  expectTrue(fc1._storesSameUnderlyingCollection(rc0))
+  expectTrue(storesSameUnderlyingCollection(fc1, rc0))
 
   let a1 = ContiguousArray(rc0.lazy.reversed())
   expectEqual(a0, a1)