From: Farrel Lifson <farrel.lifson@...>
Date: 2006-09-12T16:47:08+09:00
Subject: Re: newbie: yaml array of arrays

On 12/09/06, allan.m.miller@gmail.com <allan.m.miller@gmail.com> wrote:
> Hello,
>
> I'm new to yaml, and yaml in Ruby.
>
> I'm trying to create a yaml file in a text editor, one part of which
> will consist of an array of of arrays.  The data structure I'm trying
> to represent is:
>
> [['a', 'b', 'c'], ['d', 'e', 'f'], ['g', 'h', 'i']]
>
> an array of three arrays.
>
> I've tried to create this yaml file in a text editor (test.cfg):
>
> -- a
>  - b
>  - c
> -- d
>  - e
>  - f
> -- g
>  - h
>  - i
>
> and read it in as follows
>
> require 'yaml'
> na = open('test.cfg') { |f| YAML.load(f) }
>
> I get a load error:
>
> $ ./test.rb
> /usr/lib/ruby/1.8/yaml.rb:119:in `load': parse error on line 9, col -1:
> `' (ArgumentError)
>         from /usr/lib/ruby/1.8/yaml.rb:119:in `load'
>         from ./test.rb:3
>         from ./test.rb:3:in `open'
>         from ./test.rb:3
>
> The last line seems o be causing an ArgumentError.
>
> I'm sure my approach is completely off - how does one represent an
> array of arrays in yaml, and load it into a Ruby array of arrays?
>
> Thanks.
>
>
>

You can use IRB to work it out in reverse... start with the ruby array
and generate teh yaml from it.

irb(main):004:0>require 'yaml'
=>true
irb(main):005:0> puts [['a','b','c'],['d','e','f'],['g','h','i']].to_yaml
---
-
  - a
  - b
  - c
-
  - d
  - e
  - f
-
  - g
  - h
  - i
=>nil

Farrel