Translator – Temporary Strings (Implementation)

Upon making the changes to add temporary strings, I realized that there are more string operators than just the CatStr operator – there are the equality, relational, assign, and assign list operators, all of which can have string operands (either reference or temporary). For the equality and relational operators, the character arrays of any temporary strings need to be deleted after the comparison is made.

For the assign operator, if the operand is a reference string, then a new character array needs to be allocated and the reference string copied. However, for a temporary string, the string variable's character array can be set to the temporary character array (making it a reference string) and the current character array is deleted, eliminating the need to allocate and copy. For assigning a list, the temporary string can only be used for one of the string variables in the list, the rest need new arrays allocated.

There is already a String flag used for immediate commands, and since it's value doesn't conflict with any of the existing flags (immediate command flags are separate), it can also be used for operators and internal function codes that have string operands. A note was added to the code to make sure it's value is not used for another flag value.

A constructor was created for the new RpnItem structure that takes a token pointer, number of operands and a pointer to an operand array as arguments (the later two default to 0 and NULL). If the number of operands and operand array pointer is supplied, an operand array will be allocated for a non-zero number of operands and the operand pointers will be copied from the supplied array. A destructor was also created to delete the token and the operand array.