`scheme/base' provides a binding called `exp', which requires 2 arguments. When the compiler expands your definition, it looks at the variable reference in the body of the function *before* it binds your new `exp' definition. Therefore, it uses the `exp' that it has in scope at that time -- the one from `scheme/base'.
This is an instance of a general problem with compilation and expansion at the top-level, and one of the many reasons why it's better to write programs in modules. On Tue, Mar 8, 2011 at 7:37 AM, Yaron Gonen <[email protected]> wrote: > Hi, > (I'm using Dr Scheme version 4.2.2, with language R5RS, and the "Disallow > redefining" is not checked.) > > The following code works perfectly: > (define exp > (lambda (b e) > (if (= e 0) 1 > (* b (exp b (- e 1)))))) > (exp 2 5) > > However, when I include the line (#%require scheme/base), I get an error: > exp: expects 1 argument, given 2: 2 4 > > How is that possible? > > Many thanks, > Yaron > > _________________________________________________ > For list-related administrative tasks: > http://lists.racket-lang.org/listinfo/users > -- sam th [email protected] _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
