Add Scheme.TH
Rewrite code to build AST by using quasiquoter to improve readabilty
Fix code to safisfy 'if' treats anything but #f as true
Enrich unit tests for specifal form.
Refactoring.
Add implementations of Data type class
Remove quasiquote to evaluate directly scheme code.

it's unable to implment because 'toConstr' function for 'IO a' ( in Data.Generics.Instances module ) just raises an error.