URI Templates - embedded variables?

Hi all,

As I've been building something that makes use of a similar concept to
URI Templates, I thought I'd have a crack at building an
implementation in Ruby.

I've had a look through the list archives, but haven't seen this
mentioned: what is the expected behaviour when a variable is embedded
in another variable?

e.g.
foo = 'xyz'
bar = 'foo={foo}'
template = 'http://example.com/?{bar}'

At the moment I'm just treating the brackets as literal characters and
escaping them:
'http://example.com/?foo=%7Bfoo%7D'

but I can imagine the intention in such a case to be for the variable
to be evaluated:
'http://example.com/?foo=xyz'

-- 
Lindsay Evans
http://linz.id.au/