Date: Wed, 06 Jul 2011 10:14:56 +0100
From: Simon Marlow <marlowsd@gmail.com>
Subject: Re: [Haskell-cafe] How to ensure code executes in the context
of a specific OS thread?
To: Jason Dagit <dagitj@gmail.com>, cvs-ghc@haskell.org, Haskell Cafe
<haskell-cafe@haskell.org>
Message-ID: <4E142790.8090009@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 05/07/2011 20:33, Ian Lynagh wrote:
> On Tue, Jul 05, 2011 at 08:11:21PM +0100, Simon Marlow wrote:
>>
>> In GHCi it's a different matter, because the main thread is running
>> GHCi itself, and all the expressions/statements typed at the prompt
>> are run in forkIO'd threads (a new one for each statement, in fact).
>> If you want a way to run command-line operations in the main thread,
>> please submit a feature request. I'm not sure it can be done, but
>> I'll look into it.
>
> We already have a way: -fno-ghci-sandbox

Aha, I'd forgotten about that! Thanks Ian.

Simon

IIRC a lot of people have had trouble running GUI apps from within GHCi on OS X, whether they're GLUT, Gtk2hs, WxHaskell, or native, and several users consider this a large obstacle. I know that I haven't been successful with gtk2hs. However, at this suggestion I just tried running a gtk2hs app I'm developing with the -fno-ghci-sandbox flag, and it worked perfectly.

Thanks very much, Ian.

John L.