Just read this paper myself:
> > "AI Multilanguage System McPOPLOG: The Power of Communication
> > Between its Subsystems", I Bruha, The Computer Journal,
> > Vol 35, No 6, 1992
The paper gives only the sketchiest of details about performance
comparisons between POPLOG & McPOPLOG, unfortunately. It _looks_
as if all the benchmarks actually were done in Prolog; I draw this
tentative inference from the fact that the examples of benchmarks given in
the paper are all (as far as I can see) all in Prolog.
There is, as Ian Rogers said, a telltale remark: ``the timings depend
on the percentage of calls of standard and user-defined procedures.''
This suggests that the performance difference between system and
user-defined procedures is very noticeable. This is quite plausible.
Another key point is that the size of the POPLOG binary is given as
650Kb. I don't remember POPLOG being that small since, .... ummm ....,
1986? And POPLOG Prolog was quite new at that point. So perhaps
the comparison is complicated by an age difference, too.
On the other hand, a 75Kb implementation is jolly impressive in
these days of bloated systems. On HPPA, even the safepop11 image
is over 1300Kb and I believe (but don't know) that it even excludes
VED. [I certainly warm to the remark that ``We have found that ... they
prefer to use their own editor ... and call their own editor from
inside McPOPLOG.'' Why isn't VED just a user-loadable library? Surely
only a tiny core is _that_ performance sensitive?]
It is a shame that Bruha doesn't supply e-mail address -- it would
be interesting to check it out in more detail. Snail-mail time, I
s'pose.
Steve
PS. I couldn't see any mention of lexical/dynamic variables in the
paper. Is there one?
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