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[Caml-list] pretty printers and format and matrices
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Date: 2001-06-14 (19:37)
From: Pierre Weis <Pierre.Weis@i...>
Subject: Re: [Caml-list] pretty printers and format and matrices
> Hi, 
> I have another question about the format module:
> How can I set max_boxes to infinity?
> We use the format module to output source code of a programming
> language. For that one needs a way to advice the format module to
> print everything, regardless of how deep boxes are nested. At the
> moment we use (set_max_boxes 1000), and when we run into problems
> we increase the number.
> Bye,
> Hendrik
> -------------------
> Bug reports:  FAQ:
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Having to open more than 1000 boxes to print any material seems
incredible to me, since I used to pretty print an entire Caml compiler
within 35 boxes.

Anyway, I'm afraid there is no notion of infinity in Format. Neither
in the Caml integer values. Hence no solution to your problem.

The best you can do is to use a rough approximation, as in:

set_max_boxes max_int;;

On a regular machine this allows to simultaneously open no more than
4611686018427387903 boxes, which could be large enough to pretty print
a huge source chunk of your programming language source programs. On
the other hand, on my Ipaq handheld this limit is much smaller than
that, namely 1073741823 which may be really short for you.

If you need more than max_int simultaneously open boxes, you should
rewrite the Format module using the bignumbers facility of
Caml. However, I should admit that you will still be facing another
stupid limit (no more than 2^30 words in a big integer, which means
approximately 9 * 2 ^ 30 decimal digits on a little machine, once more
far far away from infinity). If you really need infinity, I am not aware
of any practical solution in Objective Caml.

Sorry for this unsatisfactory answer, due to stupid limitations in the

Pierre Weis

INRIA, Projet Cristal,,

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