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Today's Topics:
1. Re: Linking C library with haskell in Windows (kotshie)
2. Category question (Manfred Lotz)
----------------------------------------------------------------------
Message: 1
Date: Sun, 27 May 2012 15:28:58 -0400
From: kotshie <kots...@gmail.com>
Subject: Re: [Haskell-beginners] Linking C library with haskell in
Windows
To: Stephen Tetley <stephen.tet...@gmail.com>
Cc: beginners@haskell.org
Message-ID: <4fc2807a.3000...@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Thanks, its now solved, the problem was library conflicts with a cygwin
workspaces working along with MinGW.. Deleted cygwin and rebuild from
mingw and everything is working now.
On 05/27/2012 02:12 AM, Stephen Tetley wrote:
> I don't think changing the calling convention in the binding source
> code is a good idea.
>
> If you can build the original C library with MinGW it should have the
> same calling convention as Linux. WinAPI uses stdcall and possibly
> DLLs compiled with VC do (tip - don't use VC DLLs if you don't have
> to), but otherwise you should be using ccall.
>
>
> On 26 May 2012 19:48, kotshie<kots...@gmail.com> wrote:
>
>> I changed the stdcall on the FFI's, played with the cabal file to link to
>> different libraries, both built on VC and MinGW but still can't find the
>> solution
------------------------------
Message: 2
Date: Mon, 28 May 2012 11:54:11 +0200
From: Manfred Lotz <manfred.l...@arcor.de>
Subject: [Haskell-beginners] Category question
To: beginners@haskell.org
Message-ID: <20120528115411.0c7d7...@arcor.com>
Content-Type: text/plain; charset=US-ASCII
Hi there,
I know that this might be the wrong forum to ask. In this case I would
appreciate any hint where there is a good place to ask.
In the definition of a (mathematical) category it is said (among other
things), that for any object A there exists an identity morphism:
idA: A -> A and if f: A -> B for two objects A, B then
idB . f = f and f . idA = f
must hold.
My question: Because I cannot think of any counterexample for the
last statement I would like to know if I just could omit this
from the definition and formulate this as a small theorem.
Or does there exist a counterexample where all conditions of a category
hold but there exist two objects A, and B where we have idB . f <> f
and/or f .idA <> f?
--
Manfred
------------------------------
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