[Haskell] ANNOUNCE: GHC version 7.6.1
Felipe Almeida Lessa
felipe.lessa at gmail.com
Thu Sep 6 21:23:33 CEST 2012
On Thu, Sep 6, 2012 at 2:49 PM, Thomas DuBuisson
<thomas.dubuisson at gmail.com> wrote:
> We're getting more meta than Haskell provides cleanly, but all
> significant uses I can currently think of for something like that
> would require universal quantification over types:
>
> Forall types t.
> t `notElem` someTypes --> fails (tyUnification t MyType)
>
> I'm curious what your thinking is here.
I'm developing a EDSL for SQL queries that I'll properly announce
tomorrow. The idea I have in mind is that this code should not
typecheck:
delete $
from $ \table ->
set table []
You should not SET something inside a DELETE statement. However,
currently that will typecheck---not because I don't know how to fix
it, but because the types were already messy enough and I didn't
ponder about the tradeoffs.
So I would like to put the above snippet on a test suite that says
"this should not typecheck". It will serve both as a reminder to fix
it someday and as a regression test. Of course, I could stick each of
these on a separate file and try to compile it, but that would be a
PITA to setup. Is this a crazy idea? =P
Cheers, =)
--
Felipe.
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