Re: [Texmacs-dev] delayed scheme procedures

[Joris van der Hoeven]

On Tue, Jun 16, 2009 at 01:26:23PM +0200, Gubinelli Massimiliano wrote:
> Hi all,
>  one problem in the way to a correct Qt runloop remains the handling  
> of delayed scheme procedures (needed in autosave, user interaction,  
> periodic events, etc...). I still do not grok enough the code in tm- 
> dialougue.scm to be able to change it reliably. What is needed is a  
> restructuring of the exec-delayed interface between scheme and C++ so  
> that any explicit delay in the execution of scheme code is handled on  
> the C++ side (so that we can reimplement that with Qt timers).
> 
> Joris: could you change the "delayed" macro, or at least explain me  
> how it works? (I do not really understand the with-cc stuff going on  
> in interactive dialogs).

This is quite complicated and based on Scheme continuations.
I will need at least a day or so to dig into this code.
In any case, the idea is as follows: we keep calling exec-delayed
with a closure for the function body as long as or/and until
certain conditions are met. These conditions are listed
in the implementation of the 'delayed' macro and include
timing conditions. You would have to extract these timing
conditions and pass them as an additional parameter to
the exec-delayed routine. This is going to be a bit tough though.

Best wishes, Joris