🚀 go-pugleaf

Questions of this type can often be answered by looking at the motivation
behind the designer(s) of a programming language.  I read an article once
(which I tried to find, but could not), I think by Wirth or another person
closely associated with the Lilith project, about why Modula-2 was designed.
It seems to me that Modula-2 was designed for a specific project---as a high-
level equivalent or substitute for assembler.  The Lilith computer and the
family of system languages that include Modula-2 were essentially designed
together.  For example, the Lilith has specific machine code instructions
that aid in executing programs written in Modula-2 for the Lilith.  Thus,
although Wirth was motivated to write the best possible systems language for
this project, that does not mean it is the best possible language for all
systems.  (Of course, "best possible" does not mean perfect or even uniquely
best.)  As it happened, however, Modula-2 got a lot of attention and was
found to be relatively portable and (unlike Ada and C) simple.  Now, Modula-2
has become more than just Wirth's language and is proceeding to an inter-
national standard (just as Pascal did before it).  Wirth has apparently
moved on to a newer member of the Modula family called Oberon which simplifies
the language even more, but at the same time adds some object-oriented
features.

Good Lord...I didn't mean to write this much, but I guess that the answer is
that in many cases, Wirth designed features of the language to be closely
coupled with a specific machine since it was the principle systems language
of that machine.  Consequently, simple things like BY have what may seem to
us like odd semantic restrictions, though they would not be so odd in what
is essentially an assembly language environment.

(Stepping off my soapbox ...)

-Tim Larson
trl3@psuvm.bitnet

P.S.  If anyone can remember the article I mentioned from my rather limp
description of it I am now dying to know.  Naturally, this rambling article
came from memory and I do not discount the possibility that a few cosmic
rays may have scrambled some of my neurons over the years, so any inaccuracies
are entirely due to me.