deque-blog/dsl_arithmetic_2_partial_and_eval.hs

## dsl_arithmetic_2_partial_and_eval.hs
partial :: Env -> Expr -> Expr
partial env = cata (compAll [optimizeMul, optimizeAdd, replaceKnownVars env])

eval :: Env -> Expr -> Int
eval env expr =
  case partial env expr of
    (Fix (Cst n)) -> n
    e -> error $ "Missing vars: " ++ show (dependencies e)
	partial :: Env -> Expr -> Expr
	partial env = cata (compAll [optimizeMul, optimizeAdd, replaceKnownVars env])

	eval :: Env -> Expr -> Int
	eval env expr =
	case partial env expr of
	(Fix (Cst n)) -> n
	e -> error $ "Missing vars: " ++ show (dependencies e)