fp2/week45/mart/RefactorX.dcl

   1 definition module RefactorX
   2
   3 import StdEnv
   4
   5 :: Expr = NR Int | VAR Name | OP Expr Operator Expr | LET Name Expr Expr
   6 :: Name :== String
   7 :: Operator = PLUS | MIN | MUL | DIV
   8 :: Val = Result Int | Undef
   9
  10 from StdClass import class toString
  11
  12 instance toString Expr
  13 free :: Expr -> [Name]
  14 remove_unused_lets :: Expr -> Expr
  15 eval :: Expr -> Val