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/* Implemenation of NSScanner class
Copyright (C) 1996 Free Software Foundation, Inc.
Author: Eric Norum <eric@skatter.usask.ca>
Date: 1996
This file is part of the GNUstep Objective-C Library.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <Foundation/NSScanner.h>
#include <Foundation/NSException.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include <ctype.h> /* FIXME: May go away once I figure out Unicode */
/*
* Cache the default NSCharacterSet of characters to be skipped.
* FIXME: This would be unecessary if NSCharacterSet did the caching.
*/
static NSCharacterSet *defaultCharactersToBeSkipped;
@implementation NSScanner
/*
* Class initialization.
* Fill in default NSCharacterSet of characters to be skipped.
*/
+ (void)initialize
{
if (defaultCharactersToBeSkipped == nil)
defaultCharactersToBeSkipped =
[[NSCharacterSet whitespaceAndNewlineCharacterSet] retain];
}
/*
* Create and return a scanner that scans aString.
*/
+ scannerWithString:(NSString *)aString
{
return [[[self alloc] initWithString: aString]
autorelease];
}
+ localizedScannerWithString: (NSString*)locale
{
[self notImplemented: _cmd];
return Nil;
}
/*
* Initialize a a newly-allocated scanner to scan aString.
* Returns self.
*/
- initWithString:(NSString *)aString
{
[super init];
string = [aString copyWithZone: [self zone]];
len = [string length];
charactersToBeSkipped = defaultCharactersToBeSkipped;
return self;
}
/*
* Deallocate a scanner and all its associated storage.
*/
- (void)dealloc
{
[string release];
[locale release];
if (charactersToBeSkipped != defaultCharactersToBeSkipped)
[charactersToBeSkipped release];
[super dealloc];
}
/*
* Like scanCharactersFromSet:intoString: but no initial skip
* For internal use only.
*/
- (BOOL)_scanCharactersFromSet: (NSCharacterSet *)set
intoString: (NSString **)value;
{
unsigned int start;
if (scanLocation >= len)
return NO;
start = scanLocation;
while (scanLocation < len)
{
if (![set characterIsMember: [string characterAtIndex:scanLocation]])
break;
scanLocation++;
}
if (scanLocation == start)
return NO;
if (value)
{
NSRange range;
range.location = start;
range.length = scanLocation - start;
*value = [string substringFromRange: range];
}
return YES;
}
/*
* Scan characters to be skipped.
* Return YES if there are more characters to be scanned.
* Return NO if the end of the string is reached.
* For internal use only.
*/
- (BOOL) _skipToNextField
{
[self _scanCharactersFromSet: charactersToBeSkipped intoString: NULL];
if (scanLocation >= len)
return NO;
return YES;
}
/*
* Returns YES if no more characters remain to be scanned.
* Returns YES if all characters remaining to be scanned are to be skipped.
* Returns NO if there are characters left to scan.
*/
- (BOOL) isAtEnd
{
unsigned int save_scanLocation;
BOOL ret;
if (scanLocation >= len)
return YES;
save_scanLocation = scanLocation;
ret = ![self _skipToNextField];
scanLocation = save_scanLocation;
return ret;
}
/*
* Internal version of scanInt: method.
* Does the actual work for scanInt: except for the initial skip.
* For internal use only. This method may move the scan location
* even if a valid integer is not scanned.
* Based on the strtol code from the GNU C library. A little simpler since
* we deal only with base 10.
* FIXME: I don't use the decimalDigitCharacterSet here since it
* includes many more characters than the ASCII digits. I don't
* know how to convert those other characters, so I ignore them
* for now. For the same reason, I don't try to support all the
* possible Unicode plus and minus characters.
*/
- (BOOL) _scanInt: (int*)value
{
unsigned int num = 0;
const unsigned int limit = UINT_MAX / 10;
BOOL negative = NO;
BOOL overflow = NO;
BOOL got_digits = NO;
/* Check for sign */
switch ([string characterAtIndex:scanLocation])
{
case '+':
scanLocation++;
break;
case '-':
negative = YES;
scanLocation++;
break;
}
/* Process digits */
while (scanLocation < len)
{
unichar digit = [string characterAtIndex: scanLocation];
if ((digit < '0') || (digit > '9'))
break;
if (!overflow) {
if (num >= limit)
overflow = YES;
else
num = num * 10 + (digit - '0');
}
scanLocation++;
got_digits = YES;
}
/* Save result */
if (!got_digits)
return NO;
if (value)
{
if (num > (negative ? -(unsigned int)INT_MIN : (unsigned int)INT_MAX))
overflow = YES;
if (overflow)
num = negative ? INT_MIN: INT_MAX;
if (negative)
*value = -num;
else
*value = num;
}
return YES;
}
/*
* Scan an int into value.
*/
- (BOOL) scanInt: (int*)value
{
unsigned int saveScanLocation = scanLocation;
if ([self _skipToNextField] && [self _scanInt: value])
return YES;
scanLocation = saveScanLocation;
return NO;
}
/*
* Scan a long long int into value.
* Same as scanInt, except with different variable types and limits.
*/
- (BOOL)scanLongLong: (long long *)value
{
#if defined(LONG_LONG_MAX)
unsigned long long num = 0;
const unsigned long long limit = ULONG_LONG_MAX / 10;
BOOL negative = NO;
BOOL overflow = NO;
BOOL got_digits = NO;
unsigned int saveScanLocation = scanLocation;
/* Skip whitespace */
if (![self _skipToNextField])
{
scanLocation = saveScanLocation;
return NO;
}
/* Check for sign */
switch ([string characterAtIndex:scanLocation])
{
case '+':
scanLocation++;
break;
case '-':
negative = YES;
scanLocation++;
break;
}
/* Process digits */
while (scanLocation < len)
{
unichar digit = [string characterAtIndex:scanLocation];
if ((digit < '0') || (digit > '9'))
break;
if (!overflow) {
if (num >= limit)
overflow = YES;
else
num = num * 10 + (digit - '0');
}
scanLocation++;
got_digits = YES;
}
/* Save result */
if (!got_digits)
{
scanLocation = saveScanLocation;
return NO;
}
if (value)
{
if (num > (unsigned long long)LONG_LONG_MAX)
/* xxx When would this ever be true? Isn't is impossible? mccallum. */
overflow = YES;
if (overflow)
num = negative ? LONG_LONG_MIN: LONG_LONG_MAX;
if (negative)
*value = -num;
else
*value = num;
}
return YES;
#else /* defined(LONG_LONG_MAX) */
/*
* Provide compile-time warning and run-time exception.
*/
# warning "Can't use long long variables."
[NSException raise: NSGenericException
format:@"Can't use long long variables."];
return NO;
#endif /* defined(LONG_LONG_MAX) */
}
/*
* Scan a double into value.
* Returns YES if a valid floating-point expression was scanned.
* Returns NO otherwise.
* On overflow, HUGE_VAL or -HUGE_VAL is put into value and YES is returned.
* On underflow, 0.0 is put into value and YES is returned.
* Based on the strtod code from the GNU C library.
*/
- (BOOL)scanDouble:(double *)value
{
unichar decimal;
unichar c = 0;
double num = 0.0;
long int exponent = 0;
BOOL negative = NO;
BOOL got_dot = NO;
BOOL got_digit = NO;
unsigned int saveScanLocation = scanLocation;
/* Skip whitespace */
if (![self _skipToNextField])
{
scanLocation = saveScanLocation;
return NO;
}
/*
* FIXME: Should get decimal point character from locale. The problem
* is that I can't find anything in the OPENSTEP specification about
* the format of the locale dictionary.
*/
decimal = '.';
/* Check for sign */
switch ([string characterAtIndex:scanLocation])
{
case '+':
scanLocation++;
break;
case '-':
negative = YES;
scanLocation++;
break;
}
/* Process number */
while (scanLocation < len)
{
c = [string characterAtIndex: scanLocation];
if ((c >= '0') && (c <= '9'))
{
/* Ensure that the number being accumulated will not overflow. */
if (num >= (DBL_MAX / 10.000000001))
{
++exponent;
}
else
{
num = (num * 10.0) + (c - '0');
got_digit = YES;
}
/* Keep track of the number of digits after the decimal point.
If we just divided by 10 here, we would lose precision. */
if (got_dot)
--exponent;
}
else if (!got_dot && (c == decimal))
{
/* Note that we have found the decimal point. */
got_dot = YES;
}
else
{
/* Any other character terminates the number. */
break;
}
scanLocation++;
}
if (!got_digit)
{
scanLocation = saveScanLocation;
return NO;
}
/* Check for trailing exponent
Numbers like 1.23eFOO are rejected. */
if ((scanLocation < len) && ((c == 'e') || (c == 'E')))
{
int exp;
scanLocation++;
if (![self _scanInt: &exp])
{
scanLocation = saveScanLocation;
return NO;
}
/* Check for exponent overflow */
if (num)
{
if ((exponent > 0) && (exp > (LONG_MAX - exponent)))
exponent = LONG_MAX;
else if ((exponent < 0) && (exp < (LONG_MIN - exponent)))
exponent = LONG_MIN;
else
exponent += exp;
}
}
if (value)
{
if (num && exponent)
num *= pow(10.0, (double) exponent);
if (negative)
*value = -num;
else
*value = num;
}
return YES;
}
/*
* Scan a float into value.
* Returns YES if a valid floating-point expression was scanned.
* Returns NO otherwise.
* On overflow, HUGE_VAL or -HUGE_VAL is put into value and YES is returned.
* On underflow, 0.0 is put into value and YES is returned.
*/
- (BOOL)scanFloat: (float*)value
{
double num;
if (value == NULL)
return [self scanDouble:NULL];
if ([self scanDouble:&num])
{
*value = num;
return YES;
}
return NO;
}
/*
* Scan as long as characters from aSet are encountered.
* Returns YES if any characters were scanned.
* Returns NO if no characters were scanned.
* If value is non-NULL, and any characters were scanned, a string
* containing the scanned characters is returned by reference in value.
*/
- (BOOL)scanCharactersFromSet:(NSCharacterSet *)aSet
intoString:(NSString **)value;
{
unsigned int saveScanLocation = scanLocation;
if ([self _skipToNextField]
&& [self _scanCharactersFromSet: aSet intoString: value])
return YES;
scanLocation = saveScanLocation;
return NO;
}
/*
* Scan until a character from aSet is encountered.
* Returns YES if any characters were scanned.
* Returns NO if no characters were scanned.
* If value is non-NULL, and any characters were scanned, a string
* containing the scanned characters is returned by reference in value.
*/
- (BOOL)scanUpToCharactersFromSet:(NSCharacterSet *)set
intoString:(NSString **)value;
{
unsigned int saveScanLocation = scanLocation;
unsigned int start;
if (![self _skipToNextField])
return NO;
start = scanLocation;
while (scanLocation < len)
{
if ([set characterIsMember:[string characterAtIndex: scanLocation]])
break;
scanLocation++;
}
if (scanLocation == start)
{
scanLocation = saveScanLocation;
return NO;
}
if (value)
{
NSRange range;
range.location = start;
range.length = scanLocation - start;
*value = [string substringFromRange: range];
}
return YES;
}
/*
* Scans for aString.
* Returns YES if the characters at the scan location match aString.
* Returns NO if the characters at the scan location do not match aString.
* If the characters at the scan location match aString.
* If value is non-NULL, and the characters at the scan location match aString,
* a string containing the matching string is returned by reference in value.
*/
- (BOOL)scanString:(NSString *)aString intoString:(NSString **)value;
{
NSRange range;
unsigned int saveScanLocation = scanLocation;
[self _skipToNextField];
range.location = scanLocation;
range.length = [aString length];
range = [string rangeOfString:aString
options:caseSensitive ? 0 : NSCaseInsensitiveSearch
range:range];
if (range.length == 0)
{
scanLocation = saveScanLocation;
return NO;
}
if (value)
*value = [string substringFromRange:range];
scanLocation += range.length;
return YES;
}
/*
* Scans the string until aString is encountered..
* Returns YES if any characters were scanned.
* Returns NO if no characters were scanned.
* If value is non-NULL, and any characters were scanned, a string
* containing the scanned characters is returned by reference in value.
*/
- (BOOL)scanUpToString:(NSString *)aString
intoString:(NSString **)value;
{
NSRange range;
NSRange found;
unsigned int saveScanLocation = scanLocation;
[self _skipToNextField];
range.location = scanLocation;
range.length = len - scanLocation;
found = [string rangeOfString:aString
options:caseSensitive ? 0 : NSCaseInsensitiveSearch
range:range];
if (found.length)
range.length = found.location - scanLocation;
if (range.length == 0)
{
scanLocation = saveScanLocation;
return NO;
}
if (value)
*value = [string substringFromRange:range];
scanLocation += range.length;
return YES;
}
/*
* Returns the string being scanned.
*/
- (NSString *)string
{
return string;
}
/*
* Returns the character index at which the scanner
* will begin the next scanning operation.
*/
- (unsigned)scanLocation
{
return scanLocation;
}
/*
* Set the character location at which the scanner
* will begin the next scanning operation to anIndex.
*/
- (void)setScanLocation:(unsigned int)anIndex
{
scanLocation = anIndex;
}
/*
* Returns YES if the scanner makes a distinction
* between upper and lower case characters.
*/
- (BOOL)caseSensitive
{
return caseSensitive;
}
/*
* If flag is YES the scanner will consider upper and lower case
* to be the same during scanning. If flag is NO the scanner will
* not make a distinction between upper and lower case characters.
*/
- (void)setCaseSensitive:(BOOL)flag
{
caseSensitive = flag;
}
/*
* Return a character set object containing the characters the scanner
* will ignore when searching for the next element to be scanned.
*/
- (NSCharacterSet *)charactersToBeSkipped
{
return charactersToBeSkipped;
}
/*
* Set the characters to be ignored when the scanner
* searches for the next element to be scanned.
*/
- (void)setCharactersToBeSkipped:(NSCharacterSet *)aSet
{
if (charactersToBeSkipped != defaultCharactersToBeSkipped)
[charactersToBeSkipped release];
charactersToBeSkipped = [aSet copyWithZone: [self zone]];
}
/*
* Returns a dictionary object containing the locale
* information used by the scanner.
*/
- (NSDictionary *)locale
{
return locale;
}
/*
* Set the dictionary containing the locale
* information used by the scanner to localeDictionary.
*/
- (void)setLocale:(NSDictionary *)localeDictionary
{
locale = [localeDictionary retain];
}
/*
* NSCopying protocol
*/
- copyWithZone:(NSZone *)zone
{
NSScanner *n = [[self class] allocWithZone:zone];
[n initWithString: string];
[n setCharactersToBeSkipped: charactersToBeSkipped];
[n setLocale: locale];
[n setScanLocation: scanLocation];
[n setCaseSensitive: caseSensitive];
return n;
}
- copy
{
return [self copyWithZone: [self zone]];
}
@end
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