stdlib/NSString APIs on String: fix a bug and add tests for

rangeOfCharacterFromSet(_:options:range:)

The underlying Objective-C API could return an NSRange of NSNotFound.  Swift's
String.Index can not represent that, so change the API to return an optional
Swift Range<Index> instead.


Swift SVN r18679

stdlib/objc/Foundation/NSStringAPI.swift

@@ -77,6 +77,15 @@ extension String {
     return _index(r.location).._index(r.location + r.length)
   }
 
+  /// Return a `Range<Index>?` corresponding to the given `NSRange` of
+  /// our UTF16 representation.
+  func _optionalRange(r: NSRange) -> Range<Index>? {
+    if r.location == NSNotFound {
+      return .None
+    }
+    return _range(r)
+  }
+
   /// Invoke `body` on an `Int` buffer.  If `index` was converted from
   /// non-`nil`, convert the buffer to an `Index` and write it into the
   /// memory referred to by `index`
@@ -1062,8 +1071,8 @@ extension String {
     aSet: NSCharacterSet,
     options mask:NSStringCompareOptions = nil,
     range aRange: Range<Index>? = nil
-  )-> Range<Index> {
+  )-> Range<Index>? {
-    return _range(
+    return _optionalRange(
       _ns.rangeOfCharacterFromSet(
         aSet, options: mask,
         range: _toNSRange(aRange ? aRange! : indices(self))))

test/stdlib/NSStringAPI.swift

@@ -41,7 +41,7 @@ func expectNotEqual<T : Equatable>(
 
 %end
 
-%for (Generic, EquatableType) in [('', 'String'), ('', 'Int'), ('', 'UInt'), ('', 'NSComparisonResult'), ('<T : ForwardIndex>', 'T'), ('<T, U : Equatable>', 'Dictionary<T, U>')]:
+%for (Generic, EquatableType) in [('', 'String'), ('', 'String.Index'), ('', 'Int'), ('', 'UInt'), ('', 'NSComparisonResult'), ('<T : ForwardIndex>', 'T'), ('<T, U : Equatable>', 'Dictionary<T, U>')]:
 
 func expectEqual${Generic}(
     expected: ${EquatableType}, actual: ${EquatableType},
@@ -1002,7 +1002,39 @@ NSStringAPIs.test("propertyListFromStringsFileFormat()") {
 }
 
 NSStringAPIs.test("rangeOfCharacterFromSet(_:options:range:)") {
-  // FIXME
+  if true {
+    let charset = NSCharacterSet(charactersInString: "абв")
+    if true {
+      let s = "Глокая куздра"
+      let r = s.rangeOfCharacterFromSet(charset)!
+      expectEqual(advance(s.startIndex, 4), r.startIndex)
+      expectEqual(advance(s.startIndex, 5), r.endIndex)
+    }
+    if true {
+      expectEmpty("клмн".rangeOfCharacterFromSet(charset))
+    }
+  }
+
+  if true {
+    let charset = NSCharacterSet(charactersInString: "\u305f\u3099")
+    expectEmpty("\u3060".rangeOfCharacterFromSet(charset))
+  }
+  if true {
+    let charset = NSCharacterSet(charactersInString: "\u3060")
+    expectEmpty("\u305f\u3099".rangeOfCharacterFromSet(charset))
+  }
+
+  if true {
+    let charset = NSCharacterSet(charactersInString: "\U0001F600")
+    if true {
+      let s = "abc\U0001F600"
+      expectEqual("\U0001F600",
+          s[s.rangeOfCharacterFromSet(charset)!])
+    }
+    if true {
+      expectEmpty("abc\U0001F601".rangeOfCharacterFromSet(charset))
+    }
+  }
 }
 
 NSStringAPIs.test("rangeOfComposedCharacterSequenceAtIndex(_:)") {