From: Sean Middleditch <elanthis@...>
Date: 2002-04-04T05:18:20+09:00
Subject: Re: About efficiency

On Wed, 2002-04-03 at 15:10, Alan Stern wrote:
> Sean Middleditch <elanthis@awesomeplay.com> wrote in message news:<1017798195.15689.24.camel@stargrazer>...
> > On Tue, 2002-04-02 at 20:16, nobu.nokada@softhome.net wrote:
> > > Hi,
> > > 
> > > At Wed, 3 Apr 2002 08:51:31 +0900,
> > > Jean-Hugues ROBERT wrote:
> > > > I have been enjoying Ruby for 2 weeks now. I am very impressed. It is
> > > > my understanding that currently the interpreter directly executes the
> > > > parse tree versus going thru some bytecode generation phase (the later
> > > > is what I did for some interpreter I wrote years ago, while at the
> > > > same time a friend of mine was going the ruby way, hence we had
> > > > opportunities to compare).
> > > 
> > > Ruby VM is planned.
> > 
> > VM's make things a *lot* faster.  I'm experimenting with Scriptix, and
> > taking it from the Ruby-ish nodes to a byte-code language improved the
> > speed by 1.5-3 times, depending on the test (I'm no profressional
> > benchmark writer, mind you).
> 
> Can you (or anybody else) explain why that is so?  It's not obvious to
> me where any significant savings could accrue, except possibly from
> avoiding allocating lots of syntax tree nodes during the compile
> phase.

Well, that is a huge source of savings.  I cut the run time of smaller
scripts in half just with some compiler optimizations.  Yes, the savings
don't matter much for large applications, but a lot of people write
smaller scripts.

> 
> Alan Stern