To run BNFC:

  bnfc -m MCalc.cf
  make

To run the interpreter:

  runhaskell icalc.hs <ex1.mcalc

To run the compiler:

  runhaskell ccalc.hs <ex1.mcalc
  java Foo

Hand-written files:

  MCalc.cf             -- bnfc grammar
  Interpreter.hs       -- interpreter definition
  CodeGenerator.hs     -- code generator definition
  icalc.hs             -- interpreter main function
  ccalc.hs             -- code generator main function
  ex1.mcalc            -- example mcalc code

BNFC-generated files:

  AbsMCalc.hs          -- abstract syntax
  LexMCalc.hs          -- lexer generated by Alex
  LexMCalc.x           -- lexer source for Alex
  ParMCalc.hs          -- parser generated by Happy
  ParMCalc.y           -- parser source for Happy
  PrintCalc.hs         -- printer (from abstract syntax to strings)
  SkeletonCalc.hs      -- skeleton for pattern matching