Joel Costigliola joel-costigliola

## eval.hs
---Very simple evaluation for arithmetic expressions with only constants
---(and only "plus"...obviously extendable to other operations)

data Expr = C Float |
            Expr :+ Expr
            deriving Show

eval :: Expr -> Float
eval (C x)         = x
eval (e1 :+ e2)    =  let v1 = eval e1
	---Very simple evaluation for arithmetic expressions with only constants
	---(and only "plus"...obviously extendable to other operations)

	data Expr = C Float \|
	Expr :+ Expr
	deriving Show

	eval :: Expr -> Float
	eval (C x) = x
	eval (e1 :+ e2) = let v1 = eval e1