runParser (parseBoolExpr identifier) () "" "(a OR b) AND (n OR m) NOT (x OR y)"

Right (BAnd (BAnd (BOr (BConst "a") (BConst "b")) (BOr (BConst "n") (BConst "m"))) (BNot (BOr (BConst "x") (BConst "y"))))

it :: Either ParseError (BoolExpr String)

import Data.List (isInfixOf)
matchingDoc :: Doc -> BoolExpr String -> Bool
matchingDoc doc = evalBoolExpr (hasWord doc)

let Right query1 = runParser (parseBoolExpr identifier) () "" "Haskell"

matchingString "I really like Haskell" query1 == True

let Right query2 = runParser (parseBoolExpr identifier) () "" "Haskell NOT I"

matchingString "I really like Haskell" query2 == False

matchingString "You really like Haskell" query2 == True