ignore basic file
be able to parse very rudimentary expression, and generate some basic code from it
some cleanup
code cleanup and beautification
have a test for basic expression code gen
more work on relational ops
create debugs for relational ops
add binary operators and tests
moving towards visitors
create a better class hierarchy
create better class structure
handle identifiers correctly
throw useful exception
perform type checking for integer and boolean
fix parenthesized expressions
optimize parentheses in output
generate php constructor
make expressions testable
better type determination; more tests
be able to reduce coefficients, and minuses to pluses