Some handy addenda to NSArray, everybody’s favorite Cocoa OrderedCollection. Some are for symmetry, some are for kicks, all are for free. Enjoy.

Source for NSArray+CocoaDevUsersAdditions.h :

#import <Foundation/Foundation.h>

@interface NSArray(CocoaDevUsersAdditions)

• (NSIndexSet *) indexesForObjects: (NSArray *) array; // returns the indexes which match objects

• (NSArray *)arrayWithObjectsFromArrays:(NSArray *)arrays; //for handiness, especially with HigherOrderMessages
• (NSArray *)arrayWithClonesOf:(id)object count:(unsigned)count; //for things like FlywheelPattern or maybe a RunArray implementation.

/* please criticize these…. */

• (NSArray *)arrayWithCRLFLinesOfFile:(NSString *)filePath; // assumes CRLF

• (NSArray *)arrayWithLinesOfFile:(NSString *)filePath lineEnding:(NSString *)lineEnding;

• (BOOL)isEmpty;
• (id)firstObject;

// Unnecessary; can use -doesContain from NSComparisonMethods.

• (BOOL)containsObjectIdenticalTo:(id)anObject;

• (NSArray *)arrayByRemovingFirstObject;
• (NSArray *)arrayByRemovingLastObject;
• (NSArray *)arrayByRemovingObjectAtIndex:(unsigned)index;
• (NSArray *)arrayByRemovingObjectsInRange:(NSRange)range;
• (NSArray *)arrayByRemovingObject:(id)anObject;

• (NSArray *)arrayByRemovingObjectsFromArray:(NSArray *)unwanted;

• (NSArray *)choppedAtCount:(unsigned)count;
• (NSArray *)reversedArray;

// NOTE: results array contains instance of NSNull where result of performing selector is nil // a collection here is anything responding to -objectEnumerator

• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector;
• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withObject:(id)anObject;
• (void)makeObjectsPerformSelector:(SEL)aSelector withRespectiveObjectsFrom:(id)collection;
• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withRespectiveObjectsFrom:(id)collection;

// Quick-and-dirty NSTableView delegate methods // useful mainly for uncomplicated single-column tableViews

• (int)numberOfRowsInTableView:(NSTableView *)aTableView;

• (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex;

@end

Source for NSArray+CocoaDevUsersAdditions.m :

#import “NSArray+CocoaDevUsersAdditions.h”

@implementation NSArray(CocoaDevUsersAdditions)

• (NSIndexSet *) indexesForObjects: (NSArray *) array { NSMutableIndexSet * indexSet = [NSMutableIndexSet indexSet]; NSUInteger index; for (id obj in array) { index = [self indexOfObject:obj]; if (index != NSNotFound) [indexSet addIndex:index]; } return [NSIndexSet alloc] initWithIndexSet:indexSet] autorelease]; }

• (NSArray *)arrayWithObjectsFromArrays:(NSArray *)arrays { NSEnumerator * arrayEnumerator = [arrays objectEnumerator]; NSMutableArray * resultArray = [NSMutableArray new]; NSArray * current; while(current = [arrayEnumerator nextObject]) { [resultArray addObjectsFromArray:current]; } return [NSArray arrayWithArray:resultArray]; }

+(NSArray *)arrayWithClonesOf:(id)object count:(unsigned)count { NSMutableArray * cloneArray = [NSMutableArray arrayWithCapacity:count]; while([cloneArray count] < count) { [cloneArray addObject:object]; } return [NSArray arrayWithArray:cloneArray]; }

• (NSArray *)arrayWithCRLFLinesOfFile:(NSString *)filePath; // assumes CRLF { return [NSArray arrayWithLinesOfFile:filePath lineEnding:@”\r\n”]; }

• (NSArray *)arrayWithLinesOfFile:(NSString *)filePath lineEnding:(NSString *)lineEnding { NSArray * result = nil; NSString * theFile = [NSString stringWithContentsOfFile:filePath]; if (theFile == nil) // no string return result; // no result.

  NSArray * linesArray = [theFile componentsSeparatedByString:lineEnding]; if ([linesArray count] > 0) result = [NSArray arrayWithArray:linesArray]; return result; }

-(BOOL)isEmpty { return [self count] == 0; }

-(BOOL)isNotEmpty { return [self count] != 0; }

-(id)firstObject { return [self objectAtIndex:0]; }

• (BOOL)containsObjectIdenticalTo:(id)anObject { return (NSNotFound != [self indexOfObjectIdenticalTo:anObject]); }

• (id)arrayByRemovingFirstObject; { if ([self count] == 0) return [[self copy] autorelease]; // self might have shorter lifetime than the autorelease pool; self might be mutable return [self subarrayWithRange:NSMakeRange(1, [self count] - 1)]; }

• (id)arrayByRemovingLastObject; { if ([self count] == 0) return [[self copy] autorelease]; return [self subarrayWithRange:NSMakeRange(0, [self count] - 1)]; }

-(NSArray *)arrayByRemovingObjectAtIndex:(unsigned)index { NSMutableArray * newArray = [NSMutableArray arrayWithArray:self]; [newArray removeObjectAtIndex:index]; return [NSArray arrayWithArray:newArray]; }

-(NSArray *)arrayByRemovingObjectsInRange:(NSRange)range { NSMutableArray * newArray = [NSMutableArray arrayWithArray:self]; [newArray removeObjectsInRange:range]; return [NSArray arrayWithArray:newArray]; }

-(NSArray *)arrayByRemovingObject:(id)anObject { if(anObject == nil) { return [[self copy] autorelease]; } //dodge an exception NSMutableArray * newArray = [NSMutableArray arrayWithArray:self]; [newArray removeObject:anObject]; return [NSArray arrayWithArray:newArray]; }

• (NSArray *)arrayByRemovingObjectsFromArray:(NSArray *)unwanted { NSMutableArray * newArray = [NSMutableArray arrayWithArray:self]; [newArray removeObjectsInArray:unwanted]; return [NSArray arrayWithArray:newArray]; }

• (NSArray *)choppedAtCount:(unsigned)count { return [self subarrayWithRange:NSMakeRange(0, count)]; }

-(NSArray *)reversedArray { return [[self reverseObjectEnumerator] allObjects]; }

• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector { NSMutableArray *result = [NSMutableArray arrayWithCapacity:[self count; NSEnumerator *objectEnumerator; id obj; id objResult;

  if (aSelector == NULL) { [NSException raise:NSInvalidArgumentException format:@”aSelector cannot be NULL.”]; }

  objectEnumerator = [self objectEnumerator]; while (obj = [objectEnumerator nextObject]) { objResult = [obj performSelector:aSelector]; if (objResult == nil) objResult = [NSNull null]; [result addObject:objResult]; }

  return result; }

• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withObject:(id)anObject { NSMutableArray *result = [NSMutableArray arrayWithCapacity:[self count]]; NSEnumerator *objectEnumerator; id obj; id objResult;

  if (aSelector == NULL) { [NSException raise:NSInvalidArgumentException format:@”aSelector cannot be NULL.”]; }

  objectEnumerator = [self objectEnumerator]; while (obj = [objectEnumerator nextObject]) { objResult = [obj performSelector:aSelector withObject:anObject]; if (objResult == nil) objResult = [NSNull null]; [result addObject:objResult]; }

  return result; }

• (void)makeObjectsPerformSelector:(SEL)aSelector withRespectiveObjectsFrom:(id)collection { NSEnumerator *targetEnumerator = [self objectEnumerator]; NSEnumerator *argumentEnumerator = [collection objectEnumerator]; id target;

  while (target = [targetEnumerator nextObject]) { [target performSelector:aSelector withObject:[argumentEnumerator nextObject]]; } }

• (NSArray *)resultsOfMakeObjectsPerformSelector:(SEL)aSelector withRespectiveObjectsFrom:(id)collection { NSEnumerator *targetEnumerator = [self objectEnumerator]; NSEnumerator *argumentEnumerator = [collection objectEnumerator]; NSMutableArray *results = [NSMutableArray arrayWithCapacity:[self count]]; id target; id result;

  while (target = [targetEnumerator nextObject]) { result = [target performSelector:aSelector withObject:[argumentEnumerator nextObject]]; if (result == nil) result = [NSNull null]; [results addObject:result]; }

  return results; }

// Quick-and-dirty NSTableView delegate methods // useful mainly for uncomplicated single-column tableViews

• (int)numberOfRowsInTableView:(NSTableView *)aTableView { return [self count]; }

• (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex { return [self objectAtIndex:rowIndex]; }

@end

Category:CocoaDevUsersAdditions