Test.purs

module Test where

import Data.Foldable (traverse_)
import Control.Monad.Eff
import Control.Monad.State
import Control.Monad.State.Class

import Control.Monad.Reader
import Control.Monad.Reader.Class

import Data.String (length, split)
import Data.Array ((..))

import Debug.Trace

sumArray :: [Number] -> State Number Unit
sumArray = traverse_ $ \n -> modify (\sum -> sum + n )


paramValue :: String -> Number
paramValue "(" = 1
paramValue ")" = -1
paramValue _ = 0

isZero :: Number -> Boolean
isZero 0 = true
isZero _ = false

testState :: Number -> Number -> Number
testState x y | y >= 0 = x + y
testState _ _ = -1

testParens :: String -> Boolean
testParens = isZero <<< flip execState 0 <<< traverse_ (\c -> modify $ testState (paramValue c) ) <<< split ""

main :: forall eff. Eff ( trace :: Trace | eff) Unit
main = do
  -- trace $ show $ execState (sumArray (1 .. 11)) 0
  trace $ show $ testParens "(())())("