Re: 2.62 AT_SETUP limitations

[Eric Blake]

Ralf Wildenhues <Ralf.Wildenhues <at> gmx.de> writes:

Hi Ralf, and thanks for the review,

> > How so?  C99 supports <: and :> as the digraphs for [ and ].
> 
> I wasn't being very serious.

Well, quadrigraphs are about as close to line noise as we can get :)

> > @@ -10904,6 +10912,14 @@ m4_quote(active2, active2)
> >  @result{}ACT, IVE,ACT, IVE
> >  m4_expand([active2, active2])
> >  @result{}ACT, IVE, ACT, IVE
> > +m4_expand([case $foo in #(
> > +  [[!@@<:@@]]bar) blah ;;
> 
> How come this line doesn't end in #( ?

I was trying to show two styles in one example - you can either use a slick 
comment:
  #(
  pattern)
(as was done for the pattern "[![]", which in turn was an unbalanced shell 
pattern), or you can use a quadrigraph for unbalanced output (as was done for 
pattern *).  At any rate, you can't use:
  #(
  pattern@:}@
as that leads to unbalanced "(" (the opposite of the problem of unbalanced ")" 
normally associated with portable case statements, at least when editing the 
file you feed to autom4te).

> 
> > +  *@@:@}@@ baz ;;
> > +esac])
> > address@hidden $foo in #(
> > address@hidden  [![]) blah ;;
> 
> Likewise.

Here, the output matched what autom4te does to the input :)

Or maybe I should rewrite this into three examples: leave the existing example 
unchanged, add an example of quadrigraphs (for both unbalanced "[" and ")"), 
and add an example of portably balancing () for case statements (possibly in 
the portable shell programming section of the manual, instead of here in 
m4_expand).

-- 
Eric Blake