Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!sdcsvax!sdcc6!ix426
From: ix426@sdcc6.ucsd.EDU (tom stockfish)
Newsgroups: comp.lang.c
Subject: Re: Power operator?
Message-ID: <3585@sdcc6.ucsd.EDU>
Date: 20 Jan 88 03:11:33 GMT
References: <6982@brl-smoke.ARPA> <326@splut.UUCP> <327@splut.UUCP> <22773@hi.unm.edu> <4186@eagle.ukc.ac.uk>
Reply-To: ix426@sdcc6.ucsd.edu.UUCP (tom stockfish)
Organization: University of California, San Diego
Lines: 65

In article <4186@eagle.ukc.ac.uk> has@ukc.ac.uk (H.A.Shaw) writes:
>What people appear to be forgetting is what C is for....
>You
>should not do complex mathematical work in C, in the same way that you don't
>solve simultainous equations in troff (I have seen this done!) if you want a
>long life without ulsers.  What we need is to reduce C to it's basics.  C is
>one of a nearly infinite group of languages, each is good at only ONE job.  We
>have forgotten that C was originally a system programmers language.  Who needs
>pow() in a pager or line printer demon?  If you want maths, use FORTRAN, to
>teach, use BASIC/PASCAL, to drive a robot, use LOGO, etc., etc.  Why do you
>think we have so many languages?

The problem is, there are a million reasons *not* to use fortran for
numeric work.  For instance, on a machine running Berkely unix,

1.	f77 compiles about 50% slower than cc, on comparable source code.

2.	on a Celerity, the famous "hello world\n" program, in C, has
	a 30kbytes executable file (stripped),  whereas the fortran version
	is 100kbytes!  Essentially every fortran executable is 70kbytes larger
	than the equivalent program in C.

3.	You can't reasonably write user-friendly i/o schemes for numeric work
	in fortran.  In C you can do a lot of very nice stuff with lex and yacc.

4.	In Unix, fortran users are second-class citizens.  The symbolic
	debugger (dbx) is almost unusable with fortran.  There are two
	beautifier programs for C (cb and indent), none for fortran.  Other
	system utilities, such as awk, bc, and sh borrow much of there
	syntax from C.  If there is
	something wrong with the C compiler it gets instant attention, because
	the whole system depends on it.  For instance, a colleague's research
	ground to a halt when we upgraded from 4.1bsd to 4.2.  NONE of his
	programs worked anymore, because "print *, ..." statements no longer
	worked.  I doubt a "bug" of such magnitude would have been allowed
	to slip out in the C compiler.

5.	fortran, compared to C, is a very nasty language to write in.  The
	only time I do is when I need complex arithmetic, and then,
	I write only those subroutines I need in it.  When C++ compilers become
	widespread, I won't use fortran ever again.  (At that time I won't
	use C ever again, but that's another story).

6.	On PC's, C compilers are cheap and readily available.  Fortran
	compilers are expensive and might not fit on your machine.

Anyway, back to the issue, which is additions to the C standard to make
numeric work on C attractive.  I realize that system programmers can't live
with inside-parenthesis-only optimizations, and that numeric people will
never muck up there already difficult to read mathematical expressions
with a zillion more parentheses and unary plusses.
That is why I whole-heartedly support the previously proposed use of
[]'s to mean groupings which cannot be rearranged.  It's orthogonal,
it's mathematical looking, it's elegant, it overloads []'s no more
than parentheses are already overloaded, it's [insert your favorite
buzzword].

If a power operator is too much trouble, o.k., forget it.  But this
evaluation order thing is crucial.

I wish there were a language designed just for numerical work that was
better than C.  But nothing comes close.
-- 

||  Tom Stockfisch, UCSD Chemistry   tps@chem.ucsd.edu