From ec84f84aa83e9961274e776e9c1eb3a6d0fb22cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20P=C3=A4tzel?= <david.paetzel@posteo.de>
Date: Fri, 18 Oct 2019 13:43:18 +0200
Subject: [PATCH] Add 1-elitism as (unchangeable, for now) default

---
 src/GA.hs   | 7 +++++--
 src/Main.hs | 1 -
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/GA.hs b/src/GA.hs
index 49f24e2..987d476 100644
--- a/src/GA.hs
+++ b/src/GA.hs
@@ -174,11 +174,14 @@ step
   -> Population i
   -> m (Population i)
 step nParents nX pop = do
+  iBests <- bests 1 pop
   is <- proportionate nParents pop
   i :| is' <- children nX is
   iWorsts <- worst nParents pop
-  let popClean = foldr L.delete (NE.toList . unPop $ pop) iWorsts
-  return . Pop $ i :| is' <> popClean
+  let popClean = foldr L.delete (NE.toList . unPop $ pop) $ iBests <> iWorsts
+  -- TODO why does this not work? (we should use it!)
+  -- Pop <$> (shuffle' . NE.nub $ i :| is' <> popClean <> iBests)
+  return . Pop . NE.nub $ i :| is' <> popClean <> iBests
 
 {-|
 Runs the GA, using in each iteration
diff --git a/src/Main.hs b/src/Main.hs
index 1639f01..ae7b3d9 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -20,7 +20,6 @@ main = do
   res <- bests 5 pop'
   sequence_ $ format <$> res
   where
-    format :: (Individual i, MonadIO m, Pretty i) => i -> m ()
     format s = do
       f <- liftIO $ fitness s
       putErrText $ show f <> "\n" <> pretty s