This libary can serve as an advanced lexer for (GNU) makefiles. It parses
makefiles as "documents" and the parsing is lossless. The results are data
structures similar to DOM trees. The DOM trees hold every single bit of the
information in the original input files, including white spaces, blank lines and
makefile comments. That means it's possible to reproduce the original makefiles
from the DOM trees.  In addition, each node of the DOM trees is modifiable and
so is the whole tree, just like the PPI module used for Perl source parsing and
the HTML::TreeBuilder module used for parsing HTML source.