From 88253d03246ddb741650aa92e9f193a27c91315b Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Sun, 19 Jun 2011 05:46:58 +0300
Subject: [PATCH] htools: rewrite Cluster.filterMGResults
filterMGResults was built using a sequence of map and filter calls;
while this was logically correct, it used some incomplete pattern
matching which with the new GHC 7 triggers a warning.
The patch rewrites it using a single foldl that does both the filtering
and the mapping, in a more type-safe way.
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
---
htools/Ganeti/HTools/Cluster.hs | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/htools/Ganeti/HTools/Cluster.hs b/htools/Ganeti/HTools/Cluster.hs
index 1d18a1a87..10f34fdf3 100644
--- a/htools/Ganeti/HTools/Cluster.hs
+++ b/htools/Ganeti/HTools/Cluster.hs
@@ -685,16 +685,19 @@ solutionDescription gl (groupId, result) =
pol = apolToString (Group.allocPolicy grp)
-- | From a list of possibly bad and possibly empty solutions, filter
--- only the groups with a valid result
+-- only the groups with a valid result. Note that the result will be
+-- reversed compared to the original list
filterMGResults :: Group.List
-> [(Gdx, Result AllocSolution)]
-> [(Gdx, AllocSolution)]
-filterMGResults gl=
- filter ((/= AllocUnallocable) . Group.allocPolicy .
- flip Container.find gl . fst) .
- filter (not . null . asSolutions . snd) .
- map (\(y, Ok x) -> (y, x)) .
- filter (isOk . snd)
+filterMGResults gl = foldl' fn []
+ where unallocable = not . Group.isAllocable . flip Container.find gl
+ fn accu (gdx, rasol) =
+ case rasol of
+ Bad _ -> accu
+ Ok sol | null (asSolutions sol) -> accu
+ | unallocable gdx -> accu
+ | otherwise -> (gdx, sol):accu
-- | Sort multigroup results based on policy and score
sortMGResults :: Group.List
--
GitLab