1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #import <Foundation/Foundation.h> 20 21 @interface NSEnumerator (GRXUtil) 22 23 /** 24 * Returns a NSEnumerator instance that iterates through the elements of the passed container that 25 * supports fast enumeration. Note that this negates the speed benefits of fast enumeration over 26 * NSEnumerator. It's only intended for the rare cases when one needs the latter and only has the 27 * former, e.g. for iteration that needs to be paused and resumed later. 28 */ 29 + (NSEnumerator *)grx_enumeratorWithContainer:(id<NSFastEnumeration>)container; 30 31 /** 32 * Returns a NSEnumerator instance that provides a single object before finishing. The value is then 33 * released. 34 */ 35 + (NSEnumerator *)grx_enumeratorWithSingleValue:(id)value; 36 37 /** 38 * Returns a NSEnumerator instance that delegates the invocations of nextObject to the passed block. 39 * When the block first returns nil, it is released. 40 */ 41 + (NSEnumerator *)grx_enumeratorWithValueSupplier:(id (^)(void))block; 42 @end 43