[Gcl-devel] Re: Quality and ANSI compatibility of GCL?

[Camm Maguire]

The following message is a courtesy copy of an article
that has been posted to comp.lang.lisp as well.

Iwan van der Kleyn <address@hidden> writes:

> Hi there,
> 
> I've been looking at GCL, GNU Common Lisp. The promise of this system
> is the large number of platforms/architectures on which it runs,
> including Windows. However, according to their documentation the
> system was "originally designed to meet the CLtL1 standard" and only
> recently have they aimed for ansi compatibility.
> 
> Does anyone have experience with this? How is the quality of the
> system, as opposed to cmucl and sbcl? How is it's ansi compatibility?
> ("good enough" is good enough for me)
> 

Well, according to http://www.cliki.net/GCL:

GNU Common Lisp (GCL) is a Common Lisp implementation of the KCL
Family that uses gcc to compile Lisp into native binaries. GCL started
out as a CLtL1-level CL; steady progress is being made towards
bringing it to ANSI CL compliance: It is almost there now. CVS head is
rather close to compliance.

This was not written by me, but I agree in general with this
assessment.  I have yet to find a project that faces significant ansi
obstacles when compiling with the version currently in cvs head
(2.7.0), also available as a Debian package, 'gclcvs'.  And as others
have stated, at least with the Debian package, one gets both CLtL1 and
ANSI images, in both profiling and non-profiling flavors, with a
system wide default configured at package installation time via
debconf, and overridable at runtime by setting GCL_ANSI and/or
GCL_PROF environment variables.

We are undoubtedly still the least ANSI compliant of the freely
available systems, but as stated above, our current level of
compliance is serviceable in general.  If you have an open source
end-user application you want to port to GCL, I personally will
guarantee that GCL will be amended if necessary to support it.  I'm
much more motivated by making available real, presently-available,
high quality open source software to the world than I am in abstract
measures of compliance or utility for closed development efforts. This
said, GCL will definitely achieve full ANSI compliance -- it is our
top priority, and there is what appears to be a modest amount of work
remaining, which is currently waiting for a block of free time to
become available.

What one gets with GCL at present is stability/robustness,
performance, portability, and as Paul mentioned separately, compiler
correctness.  GCL is, for example, the vehicle that carries maxima,
acl2, and axiom to all 12 architectures in Debian.  You might want to
check out our webpage for regression results and some benchmarks.

BTW, I'm always interested in feedback from users, whether expressing
GCL's utility and importance and encouraging further work, or taking
the position that the best thing GCL could do for the world of free
lisp would be to leave the field :-).

Take care,

> Regards,
> 
> Iwan van der Kleyn

-- 
Camm Maguire                                            address@hidden
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"The earth is but one country, and mankind its citizens."  --  Baha'u'llah