NSStringOOExtensions.m

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/*
 
NSStringOOExtensions.m
 
Oolite
Copyright (C) 2004-2013 Giles C Williams and contributors
 
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
 
*/
 
#import "NSStringOOExtensions.h"
#import "NSDataOOExtensions.h"
#import "OOCocoa.h"
 
 
@implementation NSString (OOExtensions)
 
+ (instancetype) stringWithContentsOfUnicodeFile:(NSString *)path
{
    id              result = nil;
    BOOL            OK = YES;
    NSData          *data = nil;
    const uint8_t   *bytes = NULL;
    size_t          length = 0;
    const uint8_t   *effectiveBytes = NULL;
    size_t          effectiveLength = 0;
    
    data = [[NSData oo_dataWithOXZFile:path] retain];
    if (data == nil) OK = NO;
    
    if (OK)
    {
        length = [data length];
        bytes = [data bytes];
    }
    
    if (OK && 2 <= length && (length % sizeof(unichar)) == 0)
    {
        // Could be UTF-16
        unichar firstChar = bytes[0];
        firstChar = (firstChar << 8) | bytes[1];    // Endianism doesn't matter, because we test both orders of BOM.
        if (firstChar == 0xFFFE || firstChar == 0xFEFF)
        {
            // Consider it to be UTF-16.
            result = [NSString stringWithCharacters:(unichar *)(bytes + sizeof(unichar)) length:(length / sizeof(unichar)) - 1];
            if (result == nil) OK = NO;
        }
    }
    
    if (OK && result == nil)
    {
        // Not UTF-16. Try UTF-8.
        if (3 <= length && bytes[0] == 0xEF && bytes[1] == 0xBB && bytes[2] == 0xBF)
        {
            // File starts with UTF-8 BOM; skip it.
            effectiveBytes = bytes + 3;
            effectiveLength = length + 3;
        }
        else
        {
            effectiveBytes = bytes;
            effectiveLength = length;
        }
        
        // Attempt to interpret as UTF-8
        result = [[[NSString alloc] initWithBytes:effectiveBytes length:effectiveLength encoding:NSUTF8StringEncoding] autorelease];
    }
    
    if (OK && result == nil)
    {
        // Not UTF-16 or UTF-8. Use ISO-Latin-1 (which should work for any byte sequence).
        result = [[[NSString alloc] initWithBytes:effectiveBytes length:effectiveLength encoding:NSISOLatin1StringEncoding] autorelease];
    }
    
    [data release];
    return result;
}
 
 
+ (instancetype) stringWithUTF16String:(const unichar *)chars
{
    size_t          length;
    const unichar   *end;
    
    if (chars == NULL) return nil;
    
    // Find length of string.
    end = chars;
    while (*end++) {}
    length = end - chars - 1;
    
    return [NSString stringWithCharacters:chars length:length];
}
 
 
- (NSData *) utf16DataWithBOM:(BOOL)includeByteOrderMark
{
    size_t          lengthInChars;
    size_t          lengthInBytes;
    unichar         *buffer = NULL;
    unichar         *characters = NULL;
    
    // Calculate sizes
    lengthInChars = [self length];
    lengthInBytes = lengthInChars * sizeof(unichar);
    if (includeByteOrderMark) lengthInBytes += sizeof(unichar);
    
    // Allocate buffer
    buffer = malloc(lengthInBytes);
    if (buffer == NULL) return nil;
    
    // write BOM (native-endian) if desired
    characters = buffer;
    if (includeByteOrderMark)
    {
        *characters++ = 0xFEFF;
    }
    
    // Get the contents
    [self getCharacters:characters];
    
    // NSData takes ownership of the buffer.
    return [NSData dataWithBytesNoCopy:buffer length:lengthInBytes freeWhenDone:YES];
}
 
 
- (uint32_t) oo_hash
{
    NSUInteger i, length = [self length];
    uint32_t hash = 5381;
    for (i = 0; i < length; i++)
    {
        hash = ((hash << 5) + hash) /* 33 * hash */ ^ [self characterAtIndex:i];
    }
    return hash;
}
 
 
- (NSString *)stringByTrimmingLeadingCharactersInSet:(NSCharacterSet *)characterSet
{
    NSRange rangeOfFirstWantedCharacter = [self rangeOfCharacterFromSet:[characterSet invertedSet]];
    if (rangeOfFirstWantedCharacter.location == NSNotFound)  return @"";
    
    return [self substringFromIndex:rangeOfFirstWantedCharacter.location];
}
 
 
- (NSString *)stringByTrimmingLeadingWhitespaceAndNewlineCharacters
{
    return [self stringByTrimmingLeadingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
}
 
 
- (NSString *)stringByTrimmingTrailingCharactersInSet:(NSCharacterSet *)characterSet
{
    NSRange rangeOfLastWantedCharacter = [self rangeOfCharacterFromSet:[characterSet invertedSet] options:NSBackwardsSearch];
    if (rangeOfLastWantedCharacter.location == NSNotFound)  return @"";
    
    return [self substringToIndex:rangeOfLastWantedCharacter.location+1]; // non-inclusive
}
 
 
- (NSString *)stringByTrimmingTrailingWhitespaceAndNewlineCharacters
{
    return [self stringByTrimmingTrailingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
}
 
@end
 
 
@implementation NSMutableString (OOExtensions)
 
- (void) appendLine:(NSString *)line
{
    [self appendString:line ? [line stringByAppendingString:@"\n"] : (NSString *)@"\n"];
}
 
 
- (void) appendFormatLine:(NSString *)fmt, ...
{
    va_list args;
    va_start(args, fmt);
    [self appendFormatLine:fmt arguments:args];
    va_end(args);
}
 
 
- (void) appendFormatLine:(NSString *)fmt arguments:(va_list)args
{
    NSString *formatted = [[NSString alloc] initWithFormat:fmt arguments:args];
    [self appendLine:formatted];
    [formatted release];
}
 
 
- (void) deleteCharacterAtIndex:(unsigned long)index
{
    [self deleteCharactersInRange:NSMakeRange(index, 1)];
}
 
@end
 
 
NSString *OOTabString(NSUInteger count)
{
    NSString * const staticTabs[] =
    {
        @"",
        @"\t",
        @"\t\t",
        @"\t\t\t",
        @"\t\t\t\t",
        @"\t\t\t\t\t",          // 5
        @"\t\t\t\t\t\t",
        @"\t\t\t\t\t\t\t",
        @"\t\t\t\t\t\t\t\t",
        @"\t\t\t\t\t\t\t\t\t",
        @"\t\t\t\t\t\t\t\t\t\t" // 10
    };
    enum { kStaticTabCount = sizeof staticTabs / sizeof *staticTabs };
    
    if (count < kStaticTabCount)
    {
        return staticTabs[count];
    }
    else
    {
        return [staticTabs[kStaticTabCount - 1] stringByAppendingString:OOTabString(count - (kStaticTabCount - 1))];
    }
}