ah, you just want internal DSLs. I just added File::Find::Rule (a query language parsed as Perl), then.

There's also Path::Class.

file("foo/bar.txt")->dir->parent->dir("baz")
[download]

It's the internal DSL equivalent of the following XPath query:

file('foo/bar.txt')->find('dir()/../baz')
[download]

Unfortunately, Path::Class wasn't designed as DSL, so it doesn't have an equivalent of

dir('.')->find('*[file()]')
[download]

Time to quote chromatic :)

The "Is It a DSL or an API?" Ten Question Checklist

Not every API is a DSL.

Otherwise every class allowing cascading method calls would be a DSL.

It doesn't "read like a conversation" and it has a lot of redundant code, mainly the objects and arrows on the LHS.

The find examples you've listed are very well designed and could easily be structured in a better readable way, being extended with a DSL frontend.

here a very good discussion on it

http://www.infoq.com/news/2007/06/dsl-or-not

update

I think I have to correct myself, since Path::Class tries to mimic XPath it should be qualified as DSL if XPath is a language.

My main problem is that I don't consider XPath to be a particularly good readable.

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!}