Or a simple RFC6570 parser (URI Template [1]) that supports variable extraction. Variable extraction isn't part of the spec [2], but at least one library implements it [3].

[1] http://tools.ietf.org/html/rfc6570

[2] http://tools.ietf.org/html/rfc6570#section-1.4 - "In general, regular expression languages are better suited for variable matching."

[3] https://github.com/sporkmonger/addressable