**This is an old revision of the document!** ----

July 27-28: Trying to improve the arith.c file: * Reducing number of global variables: in particular the err_val, tok and incomplete variables * Strategies for string management * Modify strtoul to handle a +/- sign (there are cases when I need to 'recognize' negative numbers) However, it's turning out to be a rather difficult task. The err_val and tok should have been easy to unify, but there seems to be a memory leak problem, when an error is encountered after a string token is found (and allocated). The string management is another problem. The parse_arith() function takes a struct string as input. The input() function goes along the same struct string to get the next token. But, the parsing functions dynamically allocate space for the result. I find this tree-like method of operation simpler to handle. But this can easily cause memory leak problems on parse errors, which is something I'm still trying to fix.