fakeOS Requirements python3 antlr4 Setup pip install antlr4-python3-runtime antlr4 -Dlanguage=Python3 FunctionCall.g4 Run python main.py Fun example $ set pi 3.14159265 $ set tau (mul (get pi) 2.0) $ print (format "Tau is equal to {}" (get tau)) Tau is equal to 6.2831853