[WIP] how to clean data text coming from a Book from Gutemberg

src/Gargantext/Core/Text/Clean.hs

+{-|
+Module      : Gargantext.Core.Text.Clean
+Description : Tools to clean text
+Copyright   : (c) CNRS, 2017 - present
+License     : AGPL + CECILL v3
+Maintainer  : team@gargantext.org
+Stability   : experimental
+Portability : POSIX
+
+Clean some texts before importing it.
+
+For a given Language, chose a big master piece of litteracy to analyze
+it with GarganText. Here is a an example with a famous French Writer
+that could be the incarnation of the mythic Gargantua.
+
+-}
+
+{-# LANGUAGE OverloadedStrings #-}
+
+module Gargantext.Core.Text.Clean
+  where
+
+import Gargantext.Prelude
+import Data.Text (Text)
+import qualified Data.Text as Text
+import qualified Data.List as List
+
+groupLines :: [Text] -> [Text]
+groupLines (a:x:xs) = undefined
+
+cleanText :: Text -> [Text]
+cleanText txt = List.filter (/= "")
+              $ toParagraphs
+              $ Text.lines
+              $ Text.replace "--" ""  -- removing bullets like of dialogs
+              $ Text.replace "\xd" "" txt
+
+
+toParagraphs :: [Text] -> [Text]
+toParagraphs (a:x:xs) =
+  if a == ""
+     then [a] <> toParagraphs (x:xs)
+     else if x == ""
+            then [a] <> toParagraphs (x:xs)
+            else toParagraphs $ [a <> " " <> x ] <> xs
+toParagraphs [a] = [a]
+toParagraphs [] = []
+
+