RE: [Caml-list] Vagaries of Printf variants

[David Allsopp <dra-news@metastack.com>]

Daniel Bünzli wrote:
> Le lundi, 27 octobre 2014 à 18:56, David Allsopp a écrit :
> > but I'm sure there's a reason for its being that way!
> 
> You may be interested in reading this:
> 
> http://gallium.inria.fr/blog/format6/

Thanks, that is enlightening! I guess the thing that gets "in the way" is the design decision to make %a operate on the printf-behaviour (i.e. for fprintf, it writes to a channel, for bprintf it writes to a buffer) rather than making %a and %t *always* return a string.

> P.S. If you are using formatters the problem is less acute. Nowadays you
> can simply define formatters for each of your types with:
> 
> pp : Format.formatter -> t -> unit
> 
> and a to_string function is one `Format.asprintf "%a" pp` away.

I was abusing terminology - by formatters I meant printf functions i.e. selecting between ikfprintf, kfprintf, etc. in the same functions.

I haven't looked at the 4.02 sources, but for what I'm doing in 4.01, what would actually be useful would be if Printf.mkprintf were public so that I could supply an alternate function for output_string (i.e. allow Printf.printf to proceed entirely as normal but do something ever-so-slightly different with the final result - and with a different format6 from using ksprintf).


David