NSScanner-additions.m

/*
 * Copyright (c) 2008-2012 Martin Hedenfalk <martin@vicoapp.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "NSScanner-additions.h"
#include "logging.h"

@implementation NSScanner (additions)

- (unichar)peek
{
	if ([self isAtEnd])
		return 0;
	return [[self string] characterAtIndex:[self scanLocation]];
}

- (void)inc
{
	if (![self isAtEnd])
		[self setScanLocation:[self scanLocation] + 1];
}

- (BOOL)expectCharacter:(unichar)ch
{
	if ([self peek] == ch) {
		[self inc];
		return YES;
	}
	return NO;
}

- (BOOL)scanCharacter:(unichar *)ch
{
	if ([self isAtEnd])
		return NO;
	if (ch)
		*ch = [[self string] characterAtIndex:[self scanLocation]];
	[self inc];
	return YES;
}

- (BOOL)scanUpToUnescapedCharacterFromSet:(NSCharacterSet *)toCharSet
			   appendToString:(NSMutableString *)s
			     stripEscapes:(BOOL)stripEscapes
{
	unichar ch;
	BOOL gotChar = NO;

	while ([self scanCharacter:&ch]) {
		if (ch == '\\') {
			if ([self scanCharacter:&ch]) {
				if (!stripEscapes)
					[s appendString:@"\\"];
				[s appendFormat:@"%C", ch];
			} else
				[s appendString:@"\\"];
		} else if ([toCharSet characterIsMember:ch]) {
			/* Don't swallow the end character. */
			gotChar = YES;
			[self setScanLocation:[self scanLocation] - 1];
			break;
		} else
			[s appendFormat:@"%C", ch];
	}

	DEBUG(@"scanned escaped string [%@]", s);

	return gotChar ? YES : NO;
}

- (BOOL)scanUpToUnescapedCharacterFromSet:(NSCharacterSet *)toCharSet
			       intoString:(NSString **)string
			     stripEscapes:(BOOL)stripEscapes
{
	NSMutableString *s = [NSMutableString string];
	BOOL ret = [self scanUpToUnescapedCharacterFromSet:toCharSet appendToString:s stripEscapes:stripEscapes];
	if (string)
		*string = s;
	return ret;
}

- (BOOL)scanUpToUnescapedCharacter:(unichar)toChar
                        intoString:(NSString **)string
                      stripEscapes:(BOOL)stripEscapes
{
	return [self scanUpToUnescapedCharacterFromSet:[NSCharacterSet characterSetWithRange:NSMakeRange(toChar, 1)]
					    intoString:string
					  stripEscapes:stripEscapes];
}

- (BOOL)scanUpToUnescapedCharacter:(unichar)toChar
                        intoString:(NSString **)string
{
	/* TextMate bundle commands want backslash escapes intact. sh unescapes. */
	return [self scanUpToUnescapedCharacter:toChar intoString:string stripEscapes:NO];
}

- (BOOL)scanShellVariableIntoString:(NSString **)intoString
{
	NSUInteger startLocation = [self scanLocation];

	BOOL initial = YES;

	NSMutableCharacterSet *shellVariableSet = nil;
	if (shellVariableSet == nil) {
		shellVariableSet = [[NSMutableCharacterSet alloc] init];
		[shellVariableSet formUnionWithCharacterSet:[NSCharacterSet characterSetWithRange:NSMakeRange('a', 'z' - 'a')]];
		[shellVariableSet formUnionWithCharacterSet:[NSCharacterSet characterSetWithRange:NSMakeRange('A', 'Z' - 'A')]];
		[shellVariableSet formUnionWithCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"_"]];
	}

	while (![self isAtEnd]) {
		if (![self scanCharactersFromSet:shellVariableSet intoString:nil])
			break;

		if (initial) {
			[shellVariableSet formUnionWithCharacterSet:[NSCharacterSet characterSetWithRange:NSMakeRange('0', '9' - '0')]];
			initial = NO;
		}
	}


	if ([self scanLocation] == startLocation)
		return NO;

	if (intoString)
		*intoString = [[self string] substringWithRange:NSMakeRange(startLocation, [self scanLocation] - startLocation)];
	return YES;
}

- (BOOL)scanString:(NSString *)aString
{
	return [self scanString:aString intoString:nil];
}

- (BOOL)scanKeyCode:(NSInteger *)intoKeyCode
{
	[self setCharactersToBeSkipped:nil];

	unichar ch;
	if (![self scanCharacter:&ch])
		return NO;

	if (ch == '\\') {
		/* Escaped character. */
		if ([self scanCharacter:&ch]) {
			if (intoKeyCode)
				*intoKeyCode = ch;
			return YES;
		} else {
			/* trailing backslash? treat as literal */
			if (intoKeyCode)
				*intoKeyCode = '\\';
			return YES;
		}
	} else if (ch == '<') {
		NSUInteger oldLocation = [self scanLocation];
		[self setCaseSensitive:NO];

		unsigned int modifiers = 0;
		BOOL gotModifier;
		do {
			gotModifier = YES;
			if ([self scanString:@"c-"] ||
			    [self scanString:@"ctrl-"] ||
			    [self scanString:@"control-"])
				modifiers |= NSControlKeyMask;
			else if ([self scanString:@"a-"] ||
				 [self scanString:@"m-"] ||
				 [self scanString:@"alt-"] ||
				 [self scanString:@"option-"] ||
				 [self scanString:@"meta-"])
				modifiers |= NSAlternateKeyMask;
			else if ([self scanString:@"s-"] ||
				 [self scanString:@"shift-"])
				modifiers |= NSShiftKeyMask;
			else if ([self scanString:@"d-"] ||
				 [self scanString:@"cmd-"] ||
				 [self scanString:@"command-"])
				modifiers |= NSCommandKeyMask;
			else
				gotModifier = NO;
		} while (gotModifier);

		unichar key;
		if ([self scanString:@"delete"] ||
		    [self scanString:@"del"])
			key = NSDeleteFunctionKey;
		else if ([self scanString:@"left"])
			key = NSLeftArrowFunctionKey;
		else if ([self scanString:@"right"])
			key = NSRightArrowFunctionKey;
		else if ([self scanString:@"up"])
			key = NSUpArrowFunctionKey;
		else if ([self scanString:@"down"])
			key = NSDownArrowFunctionKey;
		else if ([self scanString:@"pagedown"] ||
			 [self scanString:@"pgdn"])
			key = NSPageDownFunctionKey;
		else if ([self scanString:@"pageup"] ||
			 [self scanString:@"pgup"])
			key = NSPageUpFunctionKey;
		else if ([self scanString:@"home"])
			key = NSHomeFunctionKey;
		else if ([self scanString:@"end"])
			key = NSEndFunctionKey;
		else if ([self scanString:@"insert"] ||
			 [self scanString:@"ins"])
			key = NSInsertFunctionKey;
		else if ([self scanString:@"help"])
			key = NSHelpFunctionKey;
		else if ([self scanString:@"bs"] ||
			 [self scanString:@"backspace"])
			key = 0x7F;
		else if ([self scanString:@"tab"])
			key = 0x09;
		else if ([self scanString:@"escape"] ||
			 [self scanString:@"esc"])
			key = 0x1B;
		else if ([self scanString:@"cr"] ||
			 [self scanString:@"enter"] ||
			 [self scanString:@"return"])
			key = 0x0D;
		else if ([self scanString:@"space"])
			key = ' ';
		else if ([self scanString:@"bar"])
			key = '|';
		else if ([self scanString:@"lt"])
			key = '<';
		else if ([self scanString:@"bslash"] ||
			 [self scanString:@"backslash"])
			key = '\\';
		else if ([self scanString:@"nl"])	/* ctrl-J */
			key = 0x0A;
		else if ([self scanString:@"ff"])	/* ctrl-L */
			key = 0x0C;
		else if ([self scanString:@"nul"])
			key = 0x0;
		else if ([self scanCharacter:&key]) {
			int f;
			if ((key == 'f' || key == 'F') && [self scanInt:&f]) {
				key = NSF1FunctionKey + f - 1;
			} else if (modifiers == NSControlKeyMask &&
			    ((key >= 'a' && key <= 'z') ||
			     key == '@' ||
			     (key >= '[' && key <= '_'))) {
				/* ASCII control character 0x00 - 0x1F. */
				key = tolower(toupper(key) - '@');
				modifiers = 0;
			}
		} else
			goto failed;

		if (![self scanString:@">"])
			goto failed;
		if (intoKeyCode)
			*intoKeyCode = modifiers | key;
		return YES;

failed:
		[self setScanLocation:oldLocation];
		if (intoKeyCode)
			*intoKeyCode = '<';
	} else if (intoKeyCode)
		*intoKeyCode = ch;
	return YES;
}

- (void)skipWhitespace
{
	[self scanCharactersFromSet:[NSCharacterSet whitespaceCharacterSet] intoString:nil];
}

@end