From: Gennady <gfb@...>
Date: 2003-12-19T03:13:52+09:00
Subject: Re: Configuration Files

>  Subject: Re: Configuration Files
> From: "Ara.T.Howard" <ahoward@ngdc.noaa.gov>
> Date: Fri, 19 Dec 2003 02:11:56 +0900
> References: 88419 88424 88427
> In-reply-to: 88427
> 
> On Thu, 18 Dec 2003, Gavin Sinclair wrote:
> 
>  > Date: Thu, 18 Dec 2003 13:51:45 +0900
>  > From: Gavin Sinclair <gsinclair@soyabean.com.au>
>  > Newsgroups: comp.lang.ruby
>  > Subject: Re: Configuration Files
>  >
>  > >
>  > > That sounds like a great config file system.  I rolled my own basic 
> one
>  > > not too long ago, but having seen this, I'm thinking I'd replace 
> it. :)
>  > >
>  > > One thing I did in mine which I kind of like, but has drawbacks, is a
>  > > sort of grouping, where:
>  > > [plugin.player]
>  > > class=CommandPlayer
>  > > command=mpg123
>  > >
>  > > is the same as:
>  > > plugin.player.class=CommandPlayer
>  > > plugin.player.command=mpg123
>  > >
>  >
>  > I have a really cool way of specifying config files.  It goes like this:
>  >
>  >   plugin:
>  >     player:
>  >       class: CommandPlayer
>  >       command: mpg123
>  >
>  > However, the code for parsing this is a secret :)
> 
> i'm with you (and use it myself), but the above is problematic if you 
> actually
> want non-programmers to be able to _configure_ a system.  for example, 
> how long
> do you think it would take a non-programmer to debug this?
> 
> file config.rb:
> ========
> require 'yaml'
> config = <<-txt
> plugin:
>   player:   
>     class: CommandPlayer
>     command: mpg123
> txt
> YAML::load(config)
> 
> 
> ~/eg/ruby > ruby config.rb
> /data/ruby-1.8.0//lib/ruby/1.8/yaml.rb:39:in `load': parse error on line 
> 3, col 12: `    command: mpg123' (ArgumentError)
>         from /data/ruby-1.8.0//lib/ruby/1.8/yaml.rb:39:in `load'
>         from config.rb:8


I just got it :-). However it seems like cheating ;-) -- there were no 
tabs in Gavin's example. There are lots of issues with TABs in yaml, we 
all know. The common approach is just to avoid them alltogether. I 
usually "untab" config files before calling YAML::load

Gennady.

> 
> -a