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

[Stephen Linton]

I can’t speak for using GAP via SAGE, but if you run GAP from the command line you 
can specify files on the command line which are read and executed in the order you give them.

Alternatively you can use the Read function to load a file of code defining new functions and 
then use them interactively.

If this isn’t what you need, feel free to get back to us.

	Steve

On 9 Oct 2014, at 00:02, Douglas Wilson <douglaspardoewilson at gmail.com> wrote:

> 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/
> _______________________________________________
> Forum mailing list
> Forum at mail.gap-system.org
> http://mail.gap-system.org/mailman/listinfo/forum