-- | Break a string into words and spaces -- | It uses a simple algorithm of searching for word characters incrementally -- | Punctuation is considered whitespace, so it's best used in a sentence or -- | for highlighting purposes module Gargantext.Text.BreakWords (BrokenWord(..), breakWords) where import Prelude (Unit, discard, negate, otherwise, pure, ($), (-), (<<<), (==), (>>=)) import Data.Traversable (traverse_) import Effect (Effect) import Data.Maybe (Maybe(..)) import Data.String.CodeUnits (length, slice) -- TODO: double check i'm the right choice import Data.String.Regex (Regex) import Gargantext.Utils.Regex (cloneRegex, execRegex, getRegexLastIndex) import Gargantext.Utils.Array (push) data BrokenWord = Word String | Space String breakWords :: String -> Effect (Array BrokenWord) breakWords s = loop $ break s where loop b = breakNext b >>= (h b) h :: Breaking -> Boolean -> Effect (Array BrokenWord) h b cont | cont = loop b | otherwise = pure b.results -- Implementation -- Returns whether to continue breakNext :: Breaking -> Effect Boolean breakNext b = checkStatic (lastIndex b) where checkStatic origin | origin == length b.source = pure false | otherwise = search b >>= next' origin next' origin Nothing = finish b origin next' origin (Just w) = next b origin w next :: Breaking -> Int -> String -> Effect Boolean next b origin word = do traverse_ (pushSpace b) $ preceding b origin word pushWord b word pure true preceding :: Breaking -> Int -> String -> Maybe String preceding b origin word = p $ (lastIndex b) - (length word) where p o | o == origin = Nothing | otherwise = slice origin o b.source finish :: Breaking -> Int -> Effect Boolean finish b origin = do let last = slice origin (-1) b.source traverse_ (pushSpace b) last pure false type Breaking = { source :: String, wordRegex :: Regex, results :: Array BrokenWord } -- almost `pure` break :: String -> Breaking break s = { source, wordRegex, results } where source = s wordRegex = cloneRegex _wordRegex results = [] search :: Breaking -> Effect (Maybe String) search b = execRegex b.wordRegex b.source lastIndex :: Breaking -> Int lastIndex b = getRegexLastIndex b.wordRegex pushResult :: Breaking -> BrokenWord -> Effect Unit pushResult b = push b.results pushSpace :: Breaking -> String -> Effect Unit pushSpace b = pushResult b <<< Space pushWord :: Breaking -> String -> Effect Unit pushWord b = pushResult b <<< Word foreign import _wordRegex :: Regex