From: Ben Giddings <bg-rubytalk@...>
Date: 2004-01-27T00:21:48+09:00
Subject: Re: New to Python: my impression v. Perl/Ruby

On Jan 22, 2004, at 05:50, GGarramuno wrote:
> That is indeed interesting!   My idea that for loops were faster were
> taken from some ruby online docs stating that as one of the
> optimizations to do.  I guess that was true of ruby1.6, perhaps.  Or
> the author was just talking about arrays, only.
> If I turn the range into an array, the iteration itself is faster,
> thou.
> It seems for in and by itself is now slow in ruby1.8.1.  And an even
> bigger surprise is to find that a while loop performs the slowest
> (almost twice as slow now!!!), when it is the one that is not
> constructing anything but an integer.  Hmm...
> On the positive side, I guess this means there's still quite some room
> for optimizing these on a future ruby version.

Overall, I think it's more Matz' philosophy that you shouldn't write 
your Ruby code based on how you think the Ruby interpreter will 
perform, but rather what seems most natural.  Ruby is supposed to be 
easy for the programmer, not for the interpreter.

Aside from that, there's the philosophy of "don't optimize code too 
soon".  If a given loop is a problem when you're done -- then you can 
figure out how to speed things up at that point.   Choosing a less 
intuitive loop construct because you have read it might be faster is 
probably a mistake from a maintenance and readability point of view, 
even if at this moment, it may be faster.

Ben