The Call constructor stores the name of the callee and the list of
arguments being passed to it.
data Expr = Num Float
| Var String
| BinOp BinOp Expr Expr
data Expr = Num Float
| Var String
| BinOp BinOp Expr Expr
deriving Show
data BinOp = Add | Sub | Mul | Cmp Ordering
deriving Show
data BinOp = Add | Sub | Mul | Cmp Ordering
instance Read Expr where
readPrec = parens $ choice [ parseNum
, parseVar
instance Read Expr where
readPrec = parens $ choice [ parseNum
, parseVar
, parseBinOp "<" 10 (Cmp LT)
, parseBinOp "+" 20 Add
, parseBinOp "-" 20 Sub
, parseBinOp "<" 10 (Cmp LT)
, parseBinOp "+" 20 Add
, parseBinOp "-" 20 Sub
skipSpaces
b <- readPrec
return (BinOp op a b)
skipSpaces
b <- readPrec
return (BinOp op a b)
+ parseCall = do
+ func <- lift (munch1 isAlpha)
+ params <- lift $ between (char '(') (char ')') $
+ sepBy (readS_to_P reads)
+ (skipSpaces >> char ',' >> skipSpaces)
+ return (Call func params)
data Prototype = Prototype String [String]
deriving Show
data Prototype = Prototype String [String]
deriving Show