[plt-scheme] Is there a general overview of contracts somewhere?

Thanks. How about closures? -- Matthias

On Apr 19, 2005, at 4:03 PM, Alexander Schmolck wrote:

> Matthias Felleisen <matthias at ccs.neu.edu> writes:
>
>>> Yes, it's pretty clear that CL implementors typically *use* type 
>>> specs as
>>> pragmas for efficiency; however, the standard *does* say that 
>>> contexts that
>>> violate type specs are absolutely in error, but conforming 
>>> implementations
>>> are not *required* to detect the errors.  Thus there could be 
>>> high-quality
>>> implementations in which type specs are taken seriously.
>>
>> Do you know of one? -- Matthias
>
> How about sbcl?
>
>   <http://sbcl-internals.cliki.net/Declarations%20are%20Assertions>
>
> Cmucl will also issue compile time warnings in situations like this:
>
>     (defun f (x)
>       (declare (type (mod 10) x))
>         (+ x 1))
>     (defun g (a)
>       (declare (type (mod 10) a))
>       (f (+ 12 a)))
>
> gives
>
> ; Warning: Result is a (INTEGER 12 21), not a (VALUES &OPTIONAL (MOD 
> 10) &REST T).
>
> 'as
>