For symbols created with the factory method newStrValue:, the first character of the strValue of the symbol object must be a letter. Subsequent characters can be letters or digits. Whitespace or control characters are not allowed.
Using the factory method newChars:count:, it's possible to use arbitrary C strings as the value of the symbol; in this case Symbol just acts like a regular Objective C String class. If you intend to use the object as a mathematical symbol, it's not advised to do this as you might incorrectly interpret spaces etc. as mathematical operators.
+ newStrValue :(STR) aStringCreates a new symbol, and sets its value to a copy of aString. Returns nil if aString is not suited as value for a symbol (when the first letter is not a letter, for instance).
newChars:count:
+ newChars :(char *) aBuffer count :(int) numChars
Creates a new symbol, and sets its value to a copy of the first numChars characters of aBuffer. For this method, there are no restrictions on the C string being used.
copy
- copy
Returns a new symbol object. Copies the string.
deepCopy
- deepCopy
Equivalent to copy.
clear
- clear
Frees the memory for the string value.
strValue
- (STR) strValue
Returns the string value of the symbol. The first character is a letter, subsequent characters can be alphanumeric.
strValue:
- strValue :(STR) aString
Creates a new symbol, and sets its value to a copy of aString. Returns nil if aString is not suited as value for a symbol.
hash
- (unsigned) hash
Returns a hash value based upon the string.
isEqual:
- (BOOL) isEqual : b
Returns YES if the strValue's of both objects are equal.
compare:
- (int) compare : b
Compares the strValue's of both objects.
isLetter
- (BOOL) isLetter
Whether the symbol consists of just one character (and hence, is a letter, not a digit).
asExpression
- asExpression
Returns an expression object containing a copy of the symbol.
printToFile:
- printToFile :(FILE *) aFile
Prints the symbol to aFile.