[Groff] question regarding PIC and variable scoping

[Dwight Aplevich]

Actually, no, your first reply was not in error; it was just
not the whole story.  The question is whether there is
external access to block variables.

In the most recent example below, x is not a block
variable but is external to it. This gives another
mechanism for exporting calculated values,
but not access to block variables.

A documentation fix is in order, nothing more.

At 07:32 PM 24/06/2002 +0200, you wrote:
> > [About accessing a GNU pic variable in a block from outside]
>
> > > I think we agree that the above reference implies that i can do
> > > something like last [].variable.  This is exactly the documentation
> > > i was refering to.  So either the documentation should clarify this
> > > important distinction between variables and labels (and take out
> > > "variable or") or perhaps there is a way to add that functionality?
> >
> > This functionality is already available.  I've added the following to
> > pic.ms:
> >
> >   Variables in a block can't be directly accessed from outside; they
> >   must be converted into a position:
> >
> >     A: [
> >          xy = 5;
> >          Xy: (xy,0);
> >        ]
> >     print A.Xy.x
>
> Oops!  Error!  Please ignore this.  The right way to export the value
> of a variable within a block to the outside is to use the `:='
> operator.  The only (minor) restriction is that a variable has to be
> defined already outside of the block before you can use `:='.
>
> Example:
>
>   .PS
>   x=5
>   y=5
>   [
>     x:=3
>     y=3
>   ]
>   print x " " y
>   .PE
>
> Result of this is `3 5'.
>
> I've reworded the documentation in both pic.man and pic.ms which was
> very misleading IMHO.
>
>
>     Werner