From 587cfebf64fa73184490a5899dc568bceb618415 Mon Sep 17 00:00:00 2001
From: Duncan Coutts <duncan@haskell.org>
Date: Tue, 6 May 2008 23:44:47 +0000
Subject: [PATCH] Improve style and performance of
PackageIndex.dependencyClosure Keep the completed set as another PackageIndex
rather than a list. We want to return an index at the end anyway and in the
mean time we want to do lots of lookups to see if we've visited previously.
---
Distribution/Simple/PackageIndex.hs | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/Distribution/Simple/PackageIndex.hs b/Distribution/Simple/PackageIndex.hs
index eebb2cf2b3..57479be052 100644
--- a/Distribution/Simple/PackageIndex.hs
+++ b/Distribution/Simple/PackageIndex.hs
@@ -272,20 +272,18 @@ dependencyClosure :: PackageFixedDeps pkg
-> [PackageIdentifier]
-> Either (PackageIndex pkg)
[(pkg, [PackageIdentifier])]
-dependencyClosure index pkgids0 = case closure [] [] pkgids0 of
- (completed, []) -> Left $ fromList completed
- (completed, _) -> Right $ brokenPackages (fromList completed)
-
+dependencyClosure index pkgids0 = case closure mempty [] pkgids0 of
+ (completed, []) -> Left completed
+ (completed, _) -> Right (brokenPackages completed)
where
- closure completed failed [] = (completed, failed)
+ closure completed failed [] = (completed, failed)
closure completed failed (pkgid:pkgids) = case lookupPackageId index pkgid of
- Nothing -> closure completed (pkgid:failed) pkgids
- -- TODO: use more effecient test here:
- Just pkg | packageId pkg `elem` map packageId completed
- -> closure completed failed pkgids
- | otherwise
- -> closure (pkg:completed) failed pkgids'
- where pkgids' = depends pkg ++ pkgids
+ Nothing -> closure completed (pkgid:failed) pkgids
+ Just pkg -> case lookupPackageId completed (packageId pkg) of
+ Just _ -> closure completed failed pkgids
+ Nothing -> closure completed' failed pkgids'
+ where completed' = insert pkg completed
+ pkgids' = depends pkg ++ pkgids
-- | Given a package index where we assume we want to use all the packages
-- (use 'dependencyClosure' if you need to get such a index subset) find out
--
GitLab