Wednesday, November 4, 2009

What's new in what was once Borland Turbo Prolog?

PDC Visual Prolog has a page on what's new in 7.2

What stood out for me was anonymous predicates or "nameless clauses" as the Prolog response to "anonymous functions".

If you are interested in Tokyo Cabinet, you might want to glance back at PDC over the years and their features offering internal and external databases.  While I have been more excited about XSB and Logtalk in recent years, I have always enjoyed working in PDC.

There is something of an equivalent PROLOG in the Mercury project: both are distinctive in having a type system and in how they track determinism.  Both PDC and Mercury would like to appeal to programmers with a hankering for a functional style.

There are many active Prolog projects: the SWI-Prolog project is likely the most active in opensource and offers RDF parsing - somewhat different from that offered by XSB.

It is odd that with all the interest in Joe Armstrong and Erlang that there seems to be no up-tick in interest in Prolog and Constraint Logic Programming: the acquisition of ILog by IBM and the move of Drools into JBoss seem not to float any other boats.

Like Prologia (Prolog IV) in France, PDC now focuses on their software application offerings and not the language - but you wonder what would have happened if Apple or Microsoft had offered a Prolog to compete with Borland back in the late 80's ... but you could say the same of Smalltalk (in fairness, Apple's Objective-C is like Smalltalk and for some time Apple was home to some Smalltalk researchers.)  At least PROLOG never suffered the fate of Self and Strongtalk at the hands of SUN.

PDC was an early advocate of DSL's (Domain Specific Languages) but I do not know if these feature prominently in their own commercial packages.

Meanwhile, over at Strawberry Prolog a Windows prolog has been in a Beta for version 3.0 for almost a year: it was to contain a major innovation in the design of Prolog compilers, but I am still back at 2.9.2

If you like Eclipse, you might like AMZI Prolog 8 which comes as an Eclipse environment.  Amzi! is a pleasure to use and has great documentation if you have been away from logic programming for awhile.  But there are other options for Prologs which interface with Java and many "small" prolog interpreters about. 

One way to glimpse which Prolog implementations are active is to see which are supported by Logtalk - but that would exclude some of those which come with their own OOP frameworks .. such as PDC.

For other recent changes in PROLOG, see xsb.com and XSB at sourceforge.

If you are tracking any other PROLOG innovations, please add a comment and a link.  I have a note on Distributed Oz 1.4.0 elsewhere ...

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