// Copyright (c) 2016 Drew Crawford.//// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License.extensionString{funchasSuffix(_str:String)->Bool{letview=self.utf8[self.utf8.index(self.utf8.endIndex,offsetBy:-str.utf8.count)..<self.utf8.endIndex]varstrIndex=str.utf8.startIndexforcharinview{ifchar!=str.utf8[strIndex]{returnfalse}strIndex=str.utf8.index(after:strIndex)}returntrue}}