Re: [PATCH] b4_args is more general than only C++.

[Eric Blake]

> +2008-11-25  Akim Demaille  <address@hidden>
> +
> +     b4_args is more general than only C++.
> +     * data/lalr1.cc (b4_args, _b4_args): Move to...
> +     * data/bison.m4: here.

> +m4_define([b4_args],
> +[m4_if([$#$1],
> +       [1], [],
> +       [m4_ifval([$1],
> +                 [$1[]_$0(m4_shift($@))],
> +                 [$0(m4_shift($@))])])])

This implementation is quadratic on M4 1.4.x.  Wouldn't you rather
use a linear implementation?  Recently, there has been a lot of
churn in autoconf.git's copy of m4sugar making it even faster;
it is probably time for me to post a resync patch again.  But one
of those improvements is the addition of m4_map_args_sep; the
following is a linear implementation (with less text, to boot):

m4_define([b4_args],
[m4_shift(m4_map_args_sep([_$0(], [)], [], $@))])

m4_define([_b4_args], [m4_ifval([$1], [, $1])])

-- 
Eric Blake

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