It uses python-reconfigure[0] to parse the config files into syntas trees (similar to ASTs). Seems to be written by the same author. Either the author didn't know about Augeas[1] which aims to do the same things and has more parsers AFAIK or for some reason couldn't use it.

Edit: Here[2] is the list of Augeas lenses(parsers) -- it's pretty extensive.

[0] - http://eugeny.github.io/reconfigure/ [1] - http://augeas.net/ [2] - http://augeas.net/stock_lenses.html