Small cosmetic changes

src/Gargantext/Core/NodeStory.hs

@@ -40,11 +40,10 @@ TODO:
 - charger les listes
 -}
 
-{-# LANGUAGE Arrows #-}
-{-# LANGUAGE ConstraintKinds   #-}
-{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE BangPatterns        #-}
+{-# LANGUAGE QuasiQuotes         #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE TupleSections       #-}
 
 module Gargantext.Core.NodeStory
   ( module Gargantext.Core.NodeStory.Types
@@ -131,11 +130,13 @@ buildForest mp = unfoldForestM unfoldNode $ Map.toList mp
       let initialChildren = getChildren (mSetToList $ el ^. ngramsElementChildren)
       go initialChildren *> pure (mkTreeNode (n, el))
       where
-        go :: [ TreeNode e ]
-           -> ExceptT BuildForestError (State (Int, Set VisitedNode)) ()
+        -- This function is quite simple: the internal 'State' keeps track of the current
+        -- position of the visit, and if we discover a term we already seen before, we throw
+        -- an error, otherwise we store it in the state at the current position and carry on.
+        go :: [ TreeNode e ] -> ExceptT BuildForestError (State (Int, Set VisitedNode)) ()
         go []     = pure ()
         go (x:xs) = do
-          (pos, visited) <- get
+          (!pos, !visited) <- get
           let nt = fst x
           case Set.member (VN pos nt) visited of
             True  -> throwError $ BFE_loop_detected visited

src/Gargantext/Core/NodeStory/Types.hs

@@ -8,11 +8,9 @@ Stability   : experimental
 Portability : POSIX
 -}
 
-{-# LANGUAGE Arrows #-}
 {-# LANGUAGE ConstraintKinds   #-}
-{-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE TemplateHaskell   #-}
-{-# LANGUAGE ViewPatterns #-}
+{-# LANGUAGE ViewPatterns      #-}
 
 module Gargantext.Core.NodeStory.Types
   ( HasNodeStory