From: Jamis Buck <jgb3@...>
Date: 2004-08-21T00:12:32+09:00
Subject: Re: YAML and line numbers

why the lucky stiff wrote:
> Jamis Buck wrote:
> 
>> Is it possible (or would it be difficult to add a way) to discover the 
>> line number on which a value in a YAML document was defined?
> 
> 
> Not in the Ruby extension.  This data is available in Syck, so it's 
> possible.  Hmm-m-m.  Do you have any suggestions for how you want to 
> retrieve this?  Psuedo-code?
> 
> _why
> 
> .
> 

Perhaps something like this:

   conf = YAML.load( File.read( "package.yml" ) )
   p conf['id'] #-> "my.package.id"
   p conf['id'].line_number #-> 2

The above approach would give you the number of the first line on which 
the requested value was defined. To find the line number on which the 
key was defined, maybe something like this:

   conf.keys.each do { |key| p key.line_number }

Because dynamically adding a line_number attribute to every object read 
by the YAML parser would be prohibitively expensive for some 
applications, you may even want to make it optional:

   YAML.line_numbers = true
   conf = YAML.load(...)
   ...

Anyway, something like that would be sufficient for my needs. :)

-- 
Jamis Buck
jgb3@email.byu.edu
http://www.jamisbuck.org/jamis

"I use octal until I get to 8, and then I switch to decimal."