From: Trans <transfire@...>
Date: 2007-08-03T10:34:36+09:00
Subject: Re: ordered hashes/ yaml?



On Aug 2, 11:17 am, Joel VanderWerf <vj...@path.berkeley.edu> wrote:
> Trans wrote:
>
> ..
>
> >> but to keep this as an array, it seems nasty to step thru and read
> >> pairs/skip in twos thru the array:
> ...
> > YAML has a secondary type called an omap. It is supported in the syck
> > implementation:
>
> That still loads as an array though:
>
> require 'yaml'
>
> h = YAML.load <<EOY
>   section1: !omap
>     - link1: home
>     - link2: my page
>     - link3: logout
> EOY
>
> p h
>
> __END__
>
> Output:
>
> {"section1"=>[["link1", "home"], ["link2", "my page"], ["link3", "logout"]]}
>
> Maybe the !!omap is useful, but the thing it loads as doesn't seem to
> have a #[] method (and it's not clear the data structure is any more
> efficient than an array):
>
> require 'yaml'
>
> h = YAML.load <<EOY
>   section1: !!omap
>     - link1: home
>     - link2: my page
>     - link3: logout
> EOY
>
> p h["section1"]["link1"] # ==> undef method
>
> Anyone have any enlightenment...?

Syck isn't 1.1 compliant (AFAIK) so you have a typo in your last
example. It needs to be !omap, not !!omap.

  h = YAML::Omap['a',1,'b',2]
  => [["a", 1], ["b", 2]]
  h['a']
  => 1

T.