Posted by Steve VanDeBogart on February 16, 2004 at 08:21:58:
In Reply to: Re: P3 Questions posted by N V Krishna on February 13, 2004 at 23:01:19:
: : What is the type of (set! x 5) ? (my scheme interrpreter returns undefined)
: int
I'm having trouble coming up with the type rules for set!. Probably because there are multiple definitions that make sense. It's kind of like assignment in an OOP language in that it can change the run time type of a variable. But different because there's no declared type for variables in scheme. I guess my question is how do we deal with a program that has a set! which changes the type of a variable? Or even worse, conditionally changes the type of a variable? Does it just not type check if a set! changes the type?
--
Steve