Re: The semicolon habit (was: Q: Definition of a scripting lang.)

Peter Ludemann <ludemann@netcom.com> wrote:
: 2. REXX allows continuing a line by having the last character
: on the line as a comma. This works because comma has no
: intrinsic meaning in REXX (it can be used as an argument
: separator in procedure calls, if you want).


I dislike out-of-band bandaids like continuation characters. But I
already said my piece about that.


: I urge all scripting language designers to read Cowlishaw's book on REXX...


I have read it. I've even been to a REXX symposium. Mike and I get
along great. It's our loyal followers that tend to rip each other's
throats out.


For my part, I urge all scripting language designers not to emulate
REXX's example in allowing umpty jillion divergent implementations.


: (my flame to Larry Wall: REXX provides about as much "power" as Perl...


You have a funny definition of "about as much". Most of the folks at
the REXX symposium thought that Perl was quite a bit more powerful.
In fact, that was their main complaint. :-)


To be sure, both languages are equivalent to Turing machines, so
they're theoretically equivalent in what is *possible* to do. However,
just as with human languages, computer languages differ not so much in
what it is possible to say, but in what it is easy to say.


: while having readability sufficiently good
: that IBM managers have been know to program in it;


Stupider people than that have programmed in Perl. So there! :-)


: and it works well as an underlying language for editors (e.g., as a
: replacement for Emacs-lisp)).


That's not too surprising, since that's the sort of thing REXX was
designed for. To the first approximation, REXX is a macro assembler
for a text processing engine. It's fine for folks who want little
program structure beyond the statement, or data structure beyond the
associative array. You can do things like that in Perl, but Perl's
mandate is broader. Perl tries to make many other things easy too.
Some would say that it tries to make too many other things easy... :-)


But every language optimizes for a different set of capabilities, so you
can't really compare languages piecemeal. You can't compare a bat wing
with a bee sting. The organism lives or dies as a whole. Every living
language will fill its ecological niche (or try to) and will either
prosper, or evolve into a new niche, or go extinct.


It's no accident that a semicolon looks like a claw, and terminates things.


Larry Wall
lwall@netlabs.com
--

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