[Yaml-core] YAML validator

[<del...@st...>]

I have recently started experimenting with YAML and am considering 
using it as a high level grammar for a small language I am designing.

My question is:
Is there any way to describe a valid YAML structure so that for example 
only one entry of the name is allowed in the example below. I would 
like to see something similar to a DTD that specifies a valid structure 
and generates an error otherwise.

resources:
- resource:
name: R1
name: R2
profile: xxxxxx
and so on...

I am using the YAML.pm module. The problem here is that since the 
resource is a hash, the parser will simply overwrite one value with the 
other. As this occurrs before I receive the parsed datastructure it is 
hard to discover. I would like to have more control over what can be 
specified. I realize I can change the datastructure but would prefer
not to do this. Has any work been done on a YAML validator?

Best regards

dle