Sample Source Code

\subsection{Convert string to decimal string using prefixed notation} The input string is in prefix (16r, (10r), 8r, 2r) notation. It returns a decimal number. <<*>>= + (int) convertInteger: (NSString*) inString { <<if string is null then exit with 0>> <<Find where the prefix character is in the string>> if ( radixRange.location == NSNotFound) { <<decimal string found so return integer value directly>> } else { <<radix value found so process remainder of string>> } return returnValue; } // convertInteger @ We could return [[null]] here if returning [[NSInteger]]. <<if string is null then exit with 0>>= if ( inString == NULL ) return 0; @ <<Find where the prefix character is in the string>>= NSRange radixRange = [inString rangeOfString:@"r"]; @ %def radixRange <<decimal string found so return integer value directly>>= return (int)[inString integerValue]; @ <<radix value found so process remainder of string>>= <<extract the prefix radix>> <<set up return value>> <<Set up loop variables>> for ( int i = (int)radixLength+1; i < [inString length]; i++ ) { <<get next character into a string value>> <<get character range from list of possible digits>> <<add the digit to the return value>> } @ [[nextChar]] is a convenience variable to make things easier to read. <<get next character into a string value>>= s = [NSString stringWithFormat:@"%c", [inString characterAtIndex:i]]; @ To pull the correct value from the list of characters. <<Set up loop variables>>= NSRange charRange; @ %def charRange The range result (location) will be the multiplier for the radix. <<get character range from list of possible digits>>= charRange = [ @"0123456789ABCDEF" rangeOfCharacterFromSet: [NSCharacterSet characterSetWithCharactersInString: s]]; @ <<add the digit to the return value>>= returnValue = radix * returnValue + (int)charRange.location; @ Another convenience variable. <<Set up loop variables>>= NSString *s; @ %def s <<extract the prefix radix>>= NSUInteger radixLength = radixRange.location; NSString *radixString = [inString substringToIndex:radixLength]; int radix = [radixString intValue]; @ %def radix radixLength radixString <<set up return value>>= int returnValue = 0; @ %def returnValue