[stdlib] += no longer appends array elements

+= only extends arrays with another sequence of the same element type.

Fixes <rdar://problem/17151420> The use of the overloaded += operator in
Swift is inconsistent and confusing with Arrays.

Note that this commits generated 3 new radars against the type checker:

  <rdar://problem/17751308>
  <rdar://problem/17750582>
  <rdar://problem/17751359>

Swift SVN r20274

stdlib/core/ArrayType.swift

@@ -51,9 +51,6 @@ internal protocol ArrayType
   /// Append newElement to the Array in O(1) (amortized)
   mutating func append(newElement: Self.Generator.Element)
 
-  /// Operator form of append
-  func += (inout lhs: Self, rhs: Self.Generator.Element)
-
   /// Append elements from `sequence` to the Array
   mutating func extend<
       S : SequenceType

stdlib/core/Arrays.swift.gyb

@@ -634,10 +634,6 @@ where C.Generator.Element == T
   }
   lhs._buffer.count = newCount
 }
-
-public func += <T>(inout lhs: ${Self}<T>, rhs: T) {
-  _arrayAppend(&lhs._buffer, rhs)
-}
 % end
 
 //===--- generic helpers --------------------------------------------------===//

stdlib/core/StringUTF8.swift

@@ -153,7 +153,7 @@ extension String {
     var result = ContiguousArray<UTF8.CodeUnit>()
     result.reserveCapacity(countElements(utf8) + 1)
     result += utf8
-    result += 0
+    result.append(0)
     return result
   }
 }

stdlib/unittest/StdlibUnittest.swift.gyb

@@ -52,7 +52,7 @@ public struct SourceLocStack {
 
   func with(loc: SourceLoc) -> SourceLocStack {
     var locs = self.locs
-    locs += loc
+    locs.append(loc)
     return SourceLocStack(_locs: locs)
   }
 
@@ -354,7 +354,7 @@ func checkGenerator<
   var mutableGen = generator
   var actual: [Element] = []
   while let e = mutableGen.next() {
-    actual += e
+    actual.append(e)
   }
   expectEqual(expected, actual, stackTrace: stackTrace.withCurrentLoc())
 
@@ -398,7 +398,7 @@ func checkCollection<
       expectEqual(startIndex, collection.startIndex)
       expectEqual(endIndex, collection.endIndex)
 
-      actual += collection[index]
+      actual.append(collection[index])
       ++index
     }
 

test/stdlib/Dictionary.swift

@@ -1022,7 +1022,7 @@ func testCOW_Fast_GenerateDoesNotReallocate() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value) = gen.next() {
-    pairs += (key, value)
+    pairs += [(key, value)]
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   assert(identity1 == reinterpretCast(d))
@@ -1039,7 +1039,18 @@ func testCOW_Slow_GenerateDoesNotReallocate() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value) = gen.next() {
-    pairs += (key.value, value.value)
+    // FIXME: This doesn't work (<rdar://problem/17751308> Can't +=
+    // with array literal of pairs)
+    // pairs += [(key.value, value.value)]
+    
+    // FIXME: This doesn't work (<rdar://problem/17750582> generics over tuples)
+    // pairs.append((key.value, value.value))
+    
+    // FIXME: This doesn't work (<rdar://problem/17751359>)
+    // pairs.append(key.value, value.value)
+    
+    let kv = (key.value, value.value)
+    pairs += [kv]
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   assert(identity1 == reinterpretCast(d))
@@ -1219,7 +1230,7 @@ func testDeleteChainCollisionRandomized() {
     }
     let hashValue = uniformRandom(chainLength - chainOverlap) * collisionChains
     let k = TestKeyTy(value: value, hashValue: hashValue)
-    knownKeys += k
+    knownKeys += [k]
     return k
   }
 
@@ -1591,7 +1602,8 @@ func slurpFastEnumeration(
     for i in 0..<returnedCount {
       let key: AnyObject = state.itemsPtr[i]!
       let value: AnyObject = d.objectForKey(key)
-      pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+      let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+      pairs += [kv]
     }
   }
 
@@ -1617,7 +1629,7 @@ func slurpFastEnumerationFromObjC(
     let pair = pairAnyObject as NSArray
     let key = (pair[0] as TestObjCKeyTy).value
     let value = (pair[1] as TestObjCValueTy).value
-    pairs += (key, value)
+    pairs += [(key, value)]
   }
   return pairs
 }
@@ -1909,7 +1921,8 @@ func test_BridgedFromObjC_Verbatim_SubscriptWithIndex() {
   var pairs = Array<(Int, Int)>()
   for var i = startIndex; i != endIndex; ++i {
     var (key, value: AnyObject) = d[i]
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs += [kv]
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   assert(identity1 == reinterpretCast(d))
@@ -1940,7 +1953,8 @@ func test_BridgedFromObjC_Nonverbatim_SubscriptWithIndex() {
   var pairs = Array<(Int, Int)>()
   for var i = startIndex; i != endIndex; ++i {
     var (key, value) = d[i]
-    pairs += (key.value, value.value)
+    let kv = (key.value, value.value)
+    pairs += [kv]
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   assert(identity1 == reinterpretCast(d))
@@ -2592,7 +2606,8 @@ func test_BridgedFromObjC_Verbatim_Generate() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value: AnyObject) = gen.next() {
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   // The following is not required by the GeneratorType protocol, but
@@ -2615,7 +2630,8 @@ func test_BridgedFromObjC_Nonverbatim_Generate() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value) = gen.next() {
-    pairs += (key.value, value.value)
+    let kv = (key.value, value.value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
   // The following is not required by the GeneratorType protocol, but
@@ -2685,11 +2701,12 @@ func test_BridgedFromObjC_Verbatim_Generate_Huge() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value: AnyObject) = gen.next() {
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   var expectedPairs = Array<(Int, Int)>()
   for i in 1...32 {
-    expectedPairs += (i, 1000 + i)
+    expectedPairs += [(i, 1000 + i)]
   }
   assert(equalsUnordered(pairs, expectedPairs))
   // The following is not required by the GeneratorType protocol, but
@@ -2712,11 +2729,12 @@ func test_BridgedFromObjC_Nonverbatim_Generate_Huge() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value) = gen.next() {
-    pairs += (key.value, value.value)
+    let kv = (key.value, value.value)
+    pairs.append(kv)
   }
   var expectedPairs = Array<(Int, Int)>()
   for i in 1...32 {
-    expectedPairs += (i, 1000 + i)
+    expectedPairs += [(i, 1000 + i)]
   }
   assert(equalsUnordered(pairs, expectedPairs))
   // The following is not required by the GeneratorType protocol, but
@@ -2742,7 +2760,8 @@ func test_BridgedFromObjC_Verbatim_Generate_ParallelArray() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value: AnyObject) = gen.next() {
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   var expectedPairs = [ (10, 1111), (20, 1111), (30, 1111), (40, 1111) ]
   assert(equalsUnordered(pairs, expectedPairs))
@@ -2770,7 +2789,8 @@ func test_BridgedFromObjC_Nonverbatim_Generate_ParallelArray() {
   var gen = d.generate()
   var pairs = Array<(Int, Int)>()
   while let (key, value) = gen.next() {
-    pairs += (key.value, value.value)
+    let kv = (key.value, value.value)
+    pairs.append(kv)
   }
   var expectedPairs = [ (10, 1111), (20, 1111), (30, 1111), (40, 1111) ]
   assert(equalsUnordered(pairs, expectedPairs))
@@ -2955,7 +2975,8 @@ func test_BridgedFromObjC_Verbatim_ArrayOfDictionaries() {
     var gen = d.generate()
     var pairs = Array<(Int, Int)>()
     while let (key, value: AnyObject) = gen.next() {
-      pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+      let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+      pairs.append(kv)
     }
     var expectedPairs = [ (10, 1010 + i), (20, 1020 + i), (30, 1030 + i) ]
     assert(equalsUnordered(pairs, expectedPairs))
@@ -2979,7 +3000,8 @@ func test_BridgedFromObjC_Nonverbatim_ArrayOfDictionaries() {
     var gen = d.generate()
     var pairs = Array<(Int, Int)>()
     while let (key, value) = gen.next() {
-      pairs += (key.value, value.value)
+      let kv = (key.value, value.value)
+      pairs.append(kv)
     }
     var expectedPairs = [ (10, 1010 + i), (20, 1020 + i), (30, 1030 + i) ]
     assert(equalsUnordered(pairs, expectedPairs))
@@ -3063,7 +3085,8 @@ func test_BridgedToObjC_KeyEnumerator_NextObject() {
   var pairs = Array<(Int, Int)>()
   while let key: AnyObject = enumerator.nextObject() {
     let value: AnyObject = d.objectForKey(key)
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 
@@ -3175,7 +3198,8 @@ func test_BridgedToObjC_KeyValue_ValueTypesCustomBridged() {
   var pairs = Array<(Int, Int)>()
   while let key: AnyObject = enumerator.nextObject() {
     let value: AnyObject = d.objectForKey(key)
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 
@@ -3207,7 +3231,8 @@ func test_BridgedToObjC_Key_ValueTypeCustomBridged() {
   var pairs = Array<(Int, Int)>()
   while let key: AnyObject = enumerator.nextObject() {
     let value: AnyObject = d.objectForKey(key)
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 
@@ -3239,7 +3264,8 @@ func test_BridgedToObjC_Value_ValueTypeCustomBridged() {
   var pairs = Array<(Int, Int)>()
   while let key: AnyObject = enumerator.nextObject() {
     let value: AnyObject = d.objectForKey(key)
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 
@@ -3281,7 +3307,8 @@ func test_BridgingRoundtrip() {
   var pairs = Array<(Int, Int)>()
   while let key: AnyObject = enumerator.nextObject() {
     let value: AnyObject = d.objectForKey(key)
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 
@@ -3311,7 +3338,8 @@ func test_NSDictionaryToDictionaryCoversion() {
 
   var pairs = Array<(Int, Int)>()
   for (key, value: AnyObject) in d {
-    pairs += ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    let kv = ((key as TestObjCKeyTy).value, (value as TestObjCValueTy).value)
+    pairs.append(kv)
   }
   assert(equalsUnordered(pairs, [ (10, 1010), (20, 1020), (30, 1030) ]))
 

test/stdlib/NSStringAPI.swift

@@ -344,7 +344,7 @@ NSStringAPIs.test("enumerateLines(_:)") {
   "abc\n\ndefghi\njklm".enumerateLines {
     (line: String, inout stop: Bool)
   in
-    lines += line
+    lines.append(line)
     if lines.count == 3 {
       stop = true
     }
@@ -365,9 +365,9 @@ NSStringAPIs.test("enumerateLinguisticTagsInRange(_:scheme:options:orthography:_
       orthography: nil) {
     (tag: String, tokenRange: Range<String.Index>, sentenceRange: Range<String.Index>, inout stop: Bool)
   in
-    tags += tag
+    tags.append(tag)
-    tokens += s[tokenRange]
+    tokens.append(s[tokenRange])
-    sentences += s[sentenceRange]
+    sentences.append(s[sentenceRange])
     if tags.count == 3 {
       stop = true
     }
@@ -391,7 +391,7 @@ NSStringAPIs.test("enumerateSubstringsInRange(_:options:_:)") {
     (substring: String, substringRange: Range<String.Index>,
      enclosingRange: Range<String.Index>, inout stop: Bool)
   in
-    substrings += substring
+    substrings.append(substring)
     expectEqual(substring, s[substringRange])
     expectEqual(substring, s[enclosingRange])
   }
@@ -426,7 +426,7 @@ NSStringAPIs.test("getBytes(_:maxLength:usedLength:encoding:options:range:remain
     let bufferLength = 100
     var expectedStr: [UInt8] = Array("def где ".utf8)
     while (expectedStr.count != bufferLength) {
-      expectedStr += 0xff
+      expectedStr.append(0xff)
     }
     var buffer = [UInt8](count: bufferLength, repeatedValue: 0xff)
     var usedLength = 0
@@ -447,7 +447,7 @@ NSStringAPIs.test("getBytes(_:maxLength:usedLength:encoding:options:range:remain
     let bufferLength = 5
     var expectedStr: [UInt8] = Array("def ".utf8)
     while (expectedStr.count != bufferLength) {
-      expectedStr += 0xff
+      expectedStr.append(0xff)
     }
     var buffer = [UInt8](count: bufferLength, repeatedValue: 0xff)
     var usedLength = 0
@@ -467,7 +467,7 @@ NSStringAPIs.test("getBytes(_:maxLength:usedLength:encoding:options:range:remain
     let bufferLength = 100
     var expectedStr: [UInt8] = Array("def где gh жз ".utf8)
     while (expectedStr.count != bufferLength) {
-      expectedStr += 0xff
+      expectedStr.append(0xff)
     }
     var buffer = [UInt8](count: bufferLength, repeatedValue: 0xff)
     var usedLength = 0
@@ -487,7 +487,7 @@ NSStringAPIs.test("getBytes(_:maxLength:usedLength:encoding:options:range:remain
     let bufferLength = 100
     var expectedStr: [UInt8] = Array("def ".utf8)
     while (expectedStr.count != bufferLength) {
-      expectedStr += 0xff
+      expectedStr.append(0xff)
     }
     var buffer = [UInt8](count: bufferLength, repeatedValue: 0xff)
     var usedLength = 0
@@ -517,7 +517,7 @@ NSStringAPIs.test("getCString(_:maxLength:encoding:)") {
     let bufferLength = 17
     var expectedStr = map("abc あかさた\0".utf8) { $0.asSigned() }
     while (expectedStr.count != bufferLength) {
-      expectedStr += (0xff).asSigned()
+      expectedStr.append((0xff).asSigned())
     }
     var buffer = [CChar](count: bufferLength, repeatedValue: (0xff).asSigned())
     var result = s.getCString(&buffer, maxLength: 100,
@@ -548,7 +548,7 @@ NSStringAPIs.test("getFileSystemRepresentation(_:maxLength:)") {
     let bufferLength = 100
     var expectedStr = map("abc \u{305f}\u{3099}くてん\0".utf8) { $0.asSigned() }
     while (expectedStr.count != bufferLength) {
-      expectedStr += (0xff).asSigned()
+      expectedStr.append((0xff).asSigned())
     }
     var buffer = [CChar](count: bufferLength, repeatedValue: (0xff).asSigned())
     expectTrue(s.getFileSystemRepresentation(&buffer, maxLength: bufferLength))

test/stdlib/NewArray.swift.gyb

@@ -123,7 +123,7 @@ where T.Generator.Element == T._Buffer.Element,
   
   for i in x.count..<(x.capacity + 1) {
     let bufferId1a = checkReallocation(x, bufferId1, false)
-    x += 13
+    x.append(13)
   }
   let bufferId2 = checkReallocation(x, bufferId1, true)
 
@@ -157,7 +157,7 @@ where T.Generator.Element == T._Buffer.Element,
   }
 
   checkReallocations(x, "append") { (inout x: T)->() in x.append(42) }
-  checkReallocations(x, "+=") { (inout x: T)->() in x += 42 }
+  checkReallocations(x, "+=") { (inout x: T)->() in x.append(42) }
   println("done.")
 }
 
@@ -222,7 +222,7 @@ func testCocoa() {
   printSequence(a)
   // CHECK-NEXT: [foo, bar, baz]
   
-  a += "qux"
+  a.append("qux")
   printSequence(a)
   // CHECK-NEXT: [foo, bar, baz, qux]
 
@@ -309,7 +309,7 @@ func testSlice() {
   printSequence(a)                // CHECK-NEXT: [foo, bar, baz]
 
   // Appending to aSlice works...
-  aSlice += "fodder"              
+  aSlice.append("fodder")
   println("<\(aSlice.count)>")    // CHECK-NEXT: <3>
   printSequence(aSlice)           // CHECK-NEXT: [buzz, baz, fodder]
 
@@ -334,7 +334,7 @@ func testReplace(make: ()->${A}<X>) {
   // comparison later.
   var source = ContiguousArray<A.Generator.Element>()
   for x in make() {
-    source += x
+    source.append(x)
   }
   
   for i in indices(source) {

test/stdlib/String.swift

@@ -17,7 +17,7 @@ func checkUnicodeScalarViewIteration(
     var decoded: [UInt32] = []
     while i != end {
       expectTrue(i < i.successor()) // Check for Comparable conformance
-      decoded += us[i].value
+      decoded.append(us[i].value)
       i = i.successor()
     }
     if expectedScalars != decoded {
@@ -34,7 +34,7 @@ func checkUnicodeScalarViewIteration(
     var decoded: [UInt32] = []
     while i != start {
       i = i.predecessor()
-      decoded += us[i].value
+      decoded.append(us[i].value)
     }
     if expectedScalars != decoded {
       return assertionFailure()

test/stdlib/Unicode.swift

@@ -329,7 +329,7 @@ func checkDecodeUTF<Codec : UnicodeCodecType>(
     var g = EOFCountingGenerator(utfStr)
     transcode(codec, UTF32.self, g,
         SinkOf {
-          decoded += $0
+          decoded.append($0)
         },
         stopOnError: true)
     expectGE(1, g.numTimesReturnedEOF)
@@ -349,7 +349,7 @@ func checkDecodeUTF<Codec : UnicodeCodecType>(
     var g = EOFCountingGenerator(utfStr)
     transcode(codec, UTF32.self, g,
         SinkOf {
-          decoded += $0
+          decoded.append($0)
         },
         stopOnError: false)
     expectEqual(1, g.numTimesReturnedEOF)
@@ -392,7 +392,7 @@ func checkEncodeUTF8(expected: [UInt8], scalars: [UInt32]) -> AssertionResult {
   var g = EOFCountingGenerator(scalars)
   let hadError = transcode(UTF32.self, UTF8.self, g,
       SinkOf {
-        encoded += $0
+        encoded.append($0)
       },
       stopOnError: true)
   expectFalse(hadError)
@@ -2261,7 +2261,7 @@ class NonContiguousNSString : NSString {
     var g = utf8.generate()
     let hadError = transcode(UTF8.self, UTF16.self, g,
         SinkOf {
-          encoded += $0
+          encoded.append($0)
         },
         stopOnError: true)
     expectFalse(hadError)
@@ -2278,7 +2278,7 @@ class NonContiguousNSString : NSString {
     var g = scalars.generate()
     let hadError = transcode(UTF32.self, UTF16.self, g,
         SinkOf {
-          encoded += $0
+          encoded.append($0)
         },
         stopOnError: true)
     expectFalse(hadError)
@@ -2337,7 +2337,7 @@ StringCookedViews.test("UTF8ForContiguousUTF16") {
     var g = test.scalars.generate()
     transcode(UTF32.self, UTF16.self, g,
         SinkOf {
-          backingStorage += $0
+          backingStorage.append($0)
         },
         stopOnError: false)
 
@@ -2360,7 +2360,7 @@ StringCookedViews.test("UTF8ForContiguousUTF16") {
     var g = expectedScalars.generate()
     transcode(UTF32.self, UTF8.self, g,
         SinkOf {
-          expected += $0
+          expected.append($0)
         },
         stopOnError: false)
 
@@ -2409,7 +2409,7 @@ StringCookedViews.test("UTF8ForNonContiguousUTF16") {
       var g = expectedScalars.generate()
       transcode(UTF32.self, UTF8.self, g,
           SinkOf {
-            expected += $0
+            expected.append($0)
           },
           stopOnError: false)
 
@@ -2475,7 +2475,7 @@ StringCookedViews.test("UTF16") {
     var g = expectedScalars.generate()
     transcode(UTF32.self, UTF16.self, g,
         SinkOf {
-          expected += $0
+          expected.append($0)
         },
         stopOnError: false)
 
@@ -2490,7 +2490,7 @@ StringCookedViews.test("UTF16") {
     var g = expectedScalars.generate()
     transcode(UTF32.self, UTF16.self, g,
         SinkOf {
-          expected += $0
+          expected.append($0)
         },
         stopOnError: false)
 

test/stdlib/UnicodeTrie.swift.gyb

@@ -82,7 +82,7 @@ class NonContiguousNSString : NSString {
     var g = scalars.generate()
     let hadError = transcode(UTF32.self, UTF16.self, g,
         SinkOf {
-          encoded += $0
+          encoded.append($0)
         },
         stopOnError: true)
     expectFalse(hadError)