[plt-scheme] typed teaching languages

OK. Any idea what to do about vector? which apparently isn't the
predicate for (Vectorof Any).

On Sun, Aug 9, 2009 at 8:00 PM, Todd O'Bryan<toddobryan at gmail.com> wrote:
> Thanks. I'll do it the way you suggested...
>
> On Sun, Aug 9, 2009 at 6:39 PM, Carl Eastlund<carl.eastlund at gmail.com> wrote:
>> Todd,
>>
>> I believe the ability to put predicate types in require/typed is
>> unsound and soon to be unsupported.  Sam can probably say more on that
>> subject if need be.  I recommend using number? to point Typed Scheme
>> in the right direction (as in the email I sent a few seconds ago,
>> which you likely had not received when you sent the below).
>>
>> Carl Eastlund
>>
>> On Sun, Aug 9, 2009 at 6:35 PM, Todd O'Bryan<toddobryan at gmail.com> wrote:
>>> As so often happens, just after sending this message I realized that I
>>> needed to convince Typed Scheme that real? is a predicate for Number,
>>> so I added
>>>
>>> (require/typed scheme [real? (Any -> Boolean : Number)])
>>>
>>> at the top, and it now works.
>>>
>>> On Sun, Aug 9, 2009 at 6:28 PM, Todd O'Bryan<toddobryan at gmail.com> wrote:
>>>> Thank you. I'm now making progress...
>>>>
>>>> However, I've hit a Typed Scheme hiccup.
>>>>
>>>> (define (positive-real? v)
>>>>  (and (real? v) (>= v 0)))
>>>>
>>>> won't type check because it thinks the second v is just an Any.
>>>>
>>>> I tried adding a type annotation (ann v Number) with a begin around
>>>> the second part of the and, but that didn't help.
>>>>
>>>> Anybody know how to give Typed Scheme the hint it needs here?
>>>>
>>>> Todd
>>
>