module RecType where 

import Target

-- Expr¤ÎÃê¾Ý¹½Ê¸
type Decl = (String, Expr)
type Decls = [Decl]

data Expr = Const Target | Let [Decl] Expr | Val Decl Expr | Var String 
          | Delay Expr 
          | Lambda String Expr | App Expr Expr | If Expr Expr Expr 
          | While Expr Expr | Begin [Expr]
            deriving Show