NSString+Hendrix.h

//
//  NSString+Hendrix.h
//  Hendrix
//
//  Created by Justin Palmer on 3/2/09.
//  Copyright 2009 Alternateidea. All rights reserved.
//
@interface NSString (Hendrix)
- (NSString *)underscore;
- (NSString *)dasherize;
@end

NSString+Hendrix.m

//
//  NSString+Hendrix.m
//  Hendrix
//
//  Created by Justin Palmer on 3/2/09.
//  Copyright 2009 Alternateidea. All rights reserved.
//

#import "NSString+Hendrix.h"

@interface NSString (HendrixPrivateMethods)
- (NSString *)normalizeWith:(NSString *)delimiter;
@end

@implementation NSString (Hendrix)

- (NSString *)dasherize
{
   return [self normalizeWith:@"-"];
}

- (NSString *)underscore
{
    return [self normalizeWith:@"_"];
}

- (NSString *)normalizeWith:(NSString *)delimeter
{
    NSString *lc = @"";
    NSUInteger length = [self length];
    NSCharacterSet *uppercaseSet = [NSCharacterSet uppercaseLetterCharacterSet];
    NSCharacterSet *delimiterSet = [NSCharacterSet characterSetWithCharactersInString:@"_-"];
    NSMutableString *out = [NSMutableString string];
    
    for (NSUInteger i = 0; i < length; i++) 
    {
        unichar uc = [self characterAtIndex:i];
        if([uppercaseSet characterIsMember:uc]) 
        {
            unichar lcc = [self characterAtIndex:(i - 1)];
            if([lc isEqualToString:delimeter] || [uppercaseSet characterIsMember:lcc] || i == 0) 
            {
                [out appendFormat:@"%C", uc];
            } 
            else 
            {
                [out appendFormat:@"%@%C", delimeter, uc];
            }
                
        } 
        else if([delimiterSet characterIsMember:uc])
        {   
            NSString *delStr = [NSString stringWithFormat:@"%C", uc];
            if(![delStr isEqualToString:delimeter] || i == 0)
            {
                [out appendString:delimeter];
                lc = delimeter;
                continue;
            }
            else
            {
                [out appendFormat:@"%C", uc];
            }
        }
        else 
        {
            [out appendFormat:@"%C", uc];
        }
    
        lc = [NSString stringWithFormat:@"%C", uc];
    }
    
    return [out lowercaseString];
}


@end