#5034: Performance of Data.Graph.{preorderF, postorderF}
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Reporter: michalt | Owner:
Type: bug | Status: patch
Priority: normal | Milestone:
Component: libraries (other) | Version: 7.0.2
Keywords: | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: Runtime performance bug
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Comment(by simonmar):
In GHC's version of this code we have
{{{
postorder :: Tree a -> [a] -> [a]
postorder (Node a ts) = postorderF ts . (a :)
postorderF :: Forest a -> [a] -> [a]
postorderF ts = foldr (.) id $ map postorder ts
}}}
which I presume fixes the problem modulo a constant factor. Care to test
with this version to see what the constant factor is?
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5034#comment:2>
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