Pascal vs C, again (was: Pascals Origins)

[b-davis at utah-cs.UUCP]

>In article <3130 at utcsri.UUCP> greg at utcsri.UUCP (Gregory Smith) writes:
>	i :=1 ;
>	while i<1000 and x[i] <> 0 do
>		i := i+1;
>	if x[i] = 0 then writeln('zero at location', i )
>	else writeln('not found');

I personally like:

	for i := 1 to 1000 do
		if x[i] = 0 then goto DONE;
	i := 1001;
DONE:
	if i <= 1000 then writeln('zero at location', i )
	else writeln('not found');

If you don't like the 'goto' then flame someplace else.  I think that
goto's can be used in a structured manner.  The statement 'i := 1001;'
is needed since the value of 'i' is undefined after the 'for' statement.
What's nice is that a good compiler can look at the 'for' loop and 
determine that bounds checking is not needed on the 'if' statement.
The 'for' loop can also be done as a single machine instruction (on
none RISC machines).  A good optimizing compiler might even be able
to generate better code than a good optimizing C compiler.

I like Pascal for some reasons and I like C for other reasons.  The
reasons usually conflict.  I don't claim to be consistant.

-- 
Brad Davis	{ihnp4, decvax, seismo}!utah-cs!b-davis	
		b-davis at utah-cs.ARPA
One drunk driver can ruin your whole day.