[Petal] [IDEA] Hash with params

[Steve Purkis]

Hi,

It's just occurred to me - we've been having problems with using 
variables to look up values in a hash through Petal.  A solution might 
be to allow:

	$key => <span petal:replace="some/hash $key">hash key</span>

A similar argument would apply to Arrays:

	list[$idx] = <span petal:replace="some/list $idx">hash key</span>

Currently these cause Petal to croak - would changing this behaviour be 
a problem?

-Steve