[comp.lang.prolog] Comparison of Edinburgh prolog and SBprolog ?

ok@goanna.oz.au (Richard O'keefe) (04/10/90)

In article <2831@ruuinf.cs.ruu.nl>, piet@cs.ruu.nl (Piet van Oostrum) writes:
> Question: has anybody compared the relative merits of Edinburgh C-Prolog
> vs. SBprolog?

C Prolog is a structure-sharing interpreter.
SB Prolog is a WAM-based compiler.  As such programs run faster and take
less memory in SB Prolog.

In terms of syntax the two are pretty close; SB Prolog has taken a mistake
which was present in some early versions of C Prolog (that "$" was not
reset to the same character class as "+" after booting, but was left in
the same class as "a", which was intended only for the booting phase) and
made it a feature.  SB Prolog has quite a few extra predicates, in particular
it supports "extension tables" (Dietrich).

C Prolog is not public domain and never has been, and so is not available
for FTP.  It is cheap to research sites, not cheap to commercial sites.
SB Prolog is not public domain either, but is covered by a GNU-style
copyleft.  It is available for FTP (from cs.arizona.edu).

You shouldn't use either SB Prolog or C Prolog for anything other than
private research, C Prolog being rather slow and SB Prolog not being
noted for robustness.