[plt-scheme] typed scheme intro

On Thu, Apr 8, 2010 at 4:15 PM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> What type annotations did you put, exactly? I tried changing the
> result of mag to Number and otherwise leaving it as is (from the docs)
> and I get this:
>
> Welcome to DrScheme, version 4.2.5.6-svn8apr2010 [3m].
> Language: typed/scheme; memory limit: 512 MB.
> . Type Checker: No function domains matched in function application:
> Domains: Exact-Nonnegative-Integer
>         Number
> Arguments: Number Number
>  in: (sqrt (sqr (pt-x p)) (sqr (pt-y p)))

That's from the missing `+' operation.
-- 
sam th
samth at ccs.neu.edu