_.purs

module Main where

import Prelude

import Control.Alt ((<|>))
import Control.Apply (lift2)
import Data.Array (catMaybes, fromFoldable)
import Data.List (List(..), many)
import Data.List as List
import Data.String.CodeUnits (fromCharArray)
import Effect (Effect)
import Effect.Console (log)
import Text.Parsing.Parser (ParserT, runParserT)
import Text.Parsing.Parser.Combinators (try, lookAhead, manyTill, optionMaybe)
import Text.Parsing.Parser.Combinators as PC
import Text.Parsing.Parser.String (anyChar, string)

data MoustacheToken = Open | Close | Character Char

instance showMoustacheToken :: Show MoustacheToken where
  show Open = "Open"
  show Close = "Close"
  show (Character s) = "(Character " <> show s <> ")"

open :: forall m. Monad m => ParserT String m MoustacheToken
open = string "{{" $> Open

close :: forall m. Monad m => ParserT String m MoustacheToken
close = string "}}" $> Close

moustacheTokens :: forall m. Monad m => ParserT String m (List MoustacheToken)
moustacheTokens = many $ open <|> close <|> (Character <$> anyChar)

main :: Effect Unit
main = log <<< show =<< runParserT example1 moustacheTokens

example1 :: String
example1 = "{{hey}}yeah {{lets go}}"

_.txt

(Right (Open : (Character 'h') : (Character 'e') : (Character 'y') : Close : (Character 'y') : (Character 'e') : (Character 'a') : (Character 'h') : (Character ' ') : Open : (Character 'l') : (Character 'e') : (Character 't') : (Character 's') : (Character ' ') : (Character 'g') : (Character 'o') : Close : Nil))