started work on markdown parser

app/Markdown.hs

@@ -1,4 +1,41 @@
+{-# LANGUAGE FlexibleContexts #-}
+
 module Markdown where
 
+import Data.Functor (void)
+import Data.Text (Text, pack)
+import Text.Parsec
+
 -- https://spec.commonmark.org/0.31.2/
 -- https://hackage.haskell.org/package/parsec
+
+linebreak ::
+  (Monad m, Stream s m Char) =>
+  ParsecT s u m ()
+-- 2 newlines due to mark
+linebreak = void (newline *> newline)
+
+emptyParse ::
+  (Monad m, Stream s m Char) =>
+  ParsecT s u m String
+emptyParse = "" <$ notFollowedBy anyChar
+
+line ::
+  (Monad m, Stream s m Char) =>
+  ParsecT s u m Text
+line = fmap pack $ many $ notFollowedBy linebreak *> anyChar
+
+lines ::
+  (Monad m, Stream s m Char) =>
+  ParsecT s u m [Text]
+lines = line `sepBy` linebreak
+
+heading ::
+  (Monad m, Stream s m Char) =>
+  ParsecT s u m (Int, Text)
+heading = do
+  level <- fmap length $ many1 $ char '#'
+  text <- line
+  pure (level, text)
+
+-- TODO: blockquote, single backticks, triple backticks, links, arb HTML