/* * Copyright 2017 Google * * 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. */ #import "FMaxNode.h" #import "FUtilities.h" #import "FEmptyNode.h" @implementation FMaxNode { } - (id) init { self = [super init]; if (self) { } return self; } + (id) maxNode { static FMaxNode *maxNode = nil; static dispatch_once_t once; dispatch_once(&once, ^{ maxNode = [[FMaxNode alloc] init]; }); return maxNode; } - (NSComparisonResult) compare:(id)other { if (other == self) { return NSOrderedSame; } else { return NSOrderedDescending; } } - (BOOL)isEqual:(id)other { return other == self; } - (id) getImmediateChild:(NSString *) childName { return [FEmptyNode emptyNode]; } - (BOOL) isEmpty { return NO; } @end