From: Alexandru Popescu <the.mindstorm.mailinglist@...>
Date: 2006-07-14T03:09:17+09:00
Subject: Re: Recursion and Ruby

(stupid question): what have you used to parse the code and show the nodes?

./alex
--
.w( the_mindstorm )p.


On 7/13/06, Dominik Bathon <dbatml@gmx.de> wrote:
> On Thu, 13 Jul 2006 15:35:33 +0200, Erik Veenstra <erikveen@gmail.com>
> wrote:
>
> >> > ----------------------------------------------------------------
> >> >
> >> >  Version 1   100,0%
> >> >  Version 2   90,3%
> >> >  Version 3   72,7%
> >> >  Version 4   70,2%
> >> >
> >> > ----------------------------------------------------------------
> >>
> >> Actually version 3 and version 4 are exactly equivalent for
> >> Ruby, it parses them both as NODE_IF:
> >
> > Well, _finally_ the AST is the same. But somehow, it's
> > slower... Maybe the translation from source/syntax to AST is
> > slower?
> >
> > The numbers don't lie. They are averages of 3 test runs, with a
> > standard deviation of almost zero. (see below for the full
> > results.)
>
> Indeed you are right, I forgot the newline nodes:
>
> >> pp <<code.parse_to_nodes.transform(:keep_newline_nodes => true)
> if a
>    b
> else
>    c
> end
> code
> [:newline,
>   {:next=>
>     [:if,
>      {:body=>[:newline, {:next=>[:vcall, {:mid=>:b}]}],
>       :else=>[:newline, {:next=>[:vcall, {:mid=>:c}]}],
>       :cond=>[:vcall, {:mid=>:a}]}]}]
> => nil
>
> vs.
>
> >> pp "a ? b : c".parse_to_nodes.transform(:keep_newline_nodes => true)
> [:newline,
>   {:next=>
>     [:if,
>      {:body=>[:vcall, {:mid=>:b}],
>       :else=>[:vcall, {:mid=>:c}],
>       :cond=>[:vcall, {:mid=>:a}]}]}]
> => nil
>
> The newline nodes are basically no-ops but they still slow things down a
> bit.
>
> In Ruby 1.9 there are no more newline nodes, so there it really is
> equivalent.
>
> Dominik
>
>