Text.Parsing.Parser.Expr

data Assoc

Constructors

• AssocNone
• AssocLeft
• AssocRight

data Operator m s a

Constructors

• Infix (ParserT s m (a -> a -> a)) Assoc
• Prefix (ParserT s m (a -> a))
• Postfix (ParserT s m (a -> a))

type OperatorTable m s a = Array (Array (Operator m s a))

buildExprParser :: forall m s a. Monad m => OperatorTable m s a -> ParserT s m a -> ParserT s m a

Build a parser from an OperatorTable.

For example:

buildExprParser [ [ Infix (string "/" $> div) AssocRight ]
                , [ Infix (string "*" $> mul) AssocRight ]
                , [ Infix (string "-" $> sub) AssocRight ]
                , [ Infix (string "+" $> add) AssocRight ]
                ] digit