[GAP Forum] Using the GAP language as an ordinary programming language

[Douglas Wilson]

I've been using Python, and therefore have
access to Sage, which includes an interface
to GAP.  So I can write a Python program
that, via Sage, will let me evaluate an
expression using GAP.

That seems a very round-about way of
using GAP, and is limited to single
expressions.  What I'd really like to do is
run a GAP language program from the
command line.  I can pass a saved workspace
to GAP on the command line, which will
be used in the subsequent interactive session,
but that is not the same thing.

I realize that the GAP is oriented towards
interactive sessions in a workspace, but surely
there are ways around that.  For example,
Smalltalk used to be the same way, but
GNU Smalltalk will allow you to specify
a program from the command line, which
it will then run and exit.

One motive for asking this is straightforward.
For me, hi-tech means making the best use
of the underlying science.  Modern computer
hardware uses a lot of technology based on
physics, and is therefore hi-tech.  Almost
all modern computer software makes little
use at all of mathematics, and therefore is
actually quite lo-tech, however sophisticated
it may seem to the user.

The future of software, in my opinion will
inevitably involve more and more use of
mathematics.  For that purpose, there should
be a highly mathematical computer
programming language.  And behold,
there is: the GAP language.  Except
for the ability to create Graphical User
Interfaces, it is functionally complete
and can do anything more ordinary
languages can.  That single deficiency
could be remedied easily be interfacing
with a simple windowing system, like Tk,
as Python does.  I'm not much interested
in writing GUI programs myself, just
ones to work from the command line.

My own work is actually quite mathematical,
and I would like to be able to do things
like specifying a group by a presentation,
identifying it, and working with it in the
usual way.  But I don't want to do it
interactively, nor do I want to be loading
up saved workspaces all the time.  I just
want to use the GAP language like any
other one.

Perhaps this capability already exists.
If so, I can fine no documentation of it
in the reference manual.  Perhaps you
could point me to some.  If it doesn't
exist yet, could it be provided somehow?

     dpw

http://DouglasPardoeWilson.SocialTechnology.ca/