[TUHS] Pic semantics

[Rob Pike via TUHS]

I tested and got the identical output from plan9port pic, which is the Plan
9 version.

-rob


On Thu, Sep 10, 2026 at 8:07 AM Noel Hunt via TUHS <tuhs at tuhs.org> wrote:

> I just compiled 'pic' from the 'v10a' distribution, and it compiled
> suprisingly easily.
> I was expecting lots of prototype errors etc.
>
> Here is what it outputs:
>
> .lf 1 test.pic
> ... 0 0 0.5 0
> ... 0.000i 0.000i 0.500i 0.000i
> .nr 00 \n(.u
> .nf
> .PS 0.000i 0.500i
> .lf 6
> \v'.2m'\h'-\w'A'u/2u'A
> .sp -1
> \h'0.500i'\v'.2m'\h'-\w'B'u/2u'B
> .sp -1
> .sp 1+0.000i
> .PE
> .if \n(00 .fi
> .lf 6
>
> On Wed, 9 Sept 2026 at 20:42, Douglas McIlroy via TUHS <tuhs at tuhs.org>
> wrote:
> >
> > I have been surprised by the handling of Pic macro arguments, quite
> > different from m4, although Brian had a hand in both. I wonder if Gnu
> > differs from the original.
> >
> > Would someone who can run a Research version of Pic be willing to try
> > it and send me Pic's (not groff's) output from the example below? The
> > issue is whether macro calls in arguments are evaluated when the
> > arguments are collected. For example, is the argument collected for
> > the macro call m(x) below x or "A"? In Gnu, it's x, so the two
> > instances of $1 ultimately become different  text.
> >
> > .PS
> > define x {"A"}
> > define m {$1; move; define x {"B"}; $1}
> > m(x)
> > .PE
> >
> > Thanks,
> > Doug
>