SPARQL JS lib, from textual syntax to algebra

Dear all,
are you aware of any Javascript library that is able to parse SPARQL and
generate a representation based on SPARQL algebra?
This step should be useful to potentially every tool working with SPARQL in
Javascript.
If there is no library already doing that, I would consider working on it.
My idea would be to leverage Ruben SPARQL parser and then transform his
JSON representation of the Abstract Syntax Tree to a representation of the
corresponding algebra tree (possibly in JSON too).

What do you think?

Miguel