Re: [Caml-list] kprintf with user formatters

["Basile Starynkevitch [local]" <basile.starynkevitch@inria.fr>]

On Thu, Jul 15, 2004 at 02:19:47PM +0200, Markus Mottl wrote:
> On Thu, 15 Jul 2004, Damien wrote:
> > I had the same problem a month ago,
> > I ended with the following ugly function:
> > 
> > let log b fmt = 
> >   if b then Printf.printf fmt
> >   else 
> >     let rec f x = Obj.magic f in 
> >       f fmt
> > (* val f: bool -> ('a, out_channel, unit) format -> 'a *)
> > 
> > (I think this is safe since f just eats its arguments, 
> >  and gets typed with "-rectypes" : ('b->'a) as 'a)
> > 
> > maybe a function "zprintf" could be added to Printf and Format to do
> > this job ?

I don't understand what this zprintf function should be, but the above
log proposal behave strangely (and perhaps unsafely) : 

# log false "a=%d s=%S\n%!" 1 "xyz";;
- : unit = <unknown constructor>


For what it's worth, long time ago, I ended writing a camlp4 extension
for a similar logging (or tracing purpose) see file README.trace and
pa_trace.ml of
http://cvs.sourceforge.net/viewcvs.py/poesia/PoesiaSoft/PoesiaMonIcap/

Regards.

-- 
Basile STARYNKEVITCH -- basile dot starynkevitch at inria dot fr
Project cristal.inria.fr - phone +33 1 3963 5197 - mobile 6 8501 2359
http://cristal.inria.fr/~starynke --- all opinions are only mine 

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