NSArray+NGAAdditions.m #1

//
//  NSArray+MBAdditions.m
//  MBMenuExtra
//
//  Created by Michael Bishop on 1/23/10.
//  Copyright 2010 Perforce Software. All rights reserved.
//

#import "NSArray+NGAAdditions.h"
#import "NGAUtilities.h"


@implementation NSArray (NGAAdditions)

-(id)arrayByRemovingObjects:(NSArray*)excludedObjects
{
    if ( excludedObjects == nil || [excludedObjects count]  == 0 )
        return AUTORELEASE( RETAIN(self) );
    
    NSMutableArray * survivingObjects = [NSMutableArray arrayWithCapacity:[self count]];
    
    for (id item in self)
    {
        if ( ![excludedObjects containsObject:item] )
            [survivingObjects addObject:item];
    }
    
    return [NSArray arrayWithArray:survivingObjects];
}

-(id)arrayByRemovingObject:(id)excludedObject
{
    if ( excludedObject == nil )
        return AUTORELEASE( RETAIN(self) );
    
    return [self arrayByRemovingObjects:[NSArray arrayWithObject:excludedObject]];
}

-(NSDictionary*)NGA_dictionaryByKeyingOnKey:(NSString*)key
{
    NSMutableDictionary * organizedResults = [NSMutableDictionary dictionaryWithCapacity:[self count]];
    
    for (NSDictionary * dictionary in self)
    {
        NSString * keyedValue = [dictionary valueForKey:key];
        
        if ( keyedValue )
            [organizedResults setObject:dictionary forKey:keyedValue];
    }
    return organizedResults;
}

-(NSDictionary*)NGA_dictionaryByKeyingOnIndex:(NSInteger)index
{
    if ( index < 0 )
        return nil;
    
    NSMutableDictionary * organizedResults = [NSMutableDictionary dictionaryWithCapacity:[self count]];
    
    for (NSArray * array in self)
    {
        if ( index < [array count] )
        {
            NSString * keyedValue = [array objectAtIndex:index];
            [organizedResults setObject:array forKey:keyedValue];
        }
    }
    return organizedResults;
}

@end

@implementation NSArray (NGAPair)
+(NSArray*) arrayFromFirstObject:(id)firstObject secondObject:(id)secondObject
{
    return [NSArray arrayWithObjects:firstObject, secondObject, nil];
}

-(id) firstObject
{
    if ( [self count] < 1 )
        return nil;
    return [self objectAtIndex:0];
}

-(id) secondObject
{
    if ( [self count] < 2 )
        return nil;
    return [self objectAtIndex:1];
}
@end


@implementation NSMutableArray (NGAArrayAdditions)

-(void)NGA_setObject:(id)object atIndex:(NSUInteger)index
{
    if (index < [self count])
    {
        [self replaceObjectAtIndex:index withObject:object];
        return;
    }
    
    // INVARIANT: index >= [self count]
    
    const NSUInteger overflow = index - [self count];
    
    for ( int i = 0; i < overflow; i++ )
        [self addObject:[NSNull null]];
    
    [self addObject:object];
}

@end