#4507: Data.List.sum and Data.List.product unnecessarily inefficient
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Reporter: pozorvlak | Owner:
Type: bug | Status: new
Priority: normal | Component: libraries/base
Version: 7.0.1 | Keywords: Data.List, sum, product, foldl'
Testcase: | Blockedby:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: None/Unknown
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Despite the advice given in
http://www.haskell.org/haskellwiki/Foldr_Foldl_Foldl%27, the versions of
sum and product in Data.List don't use foldl'. This makes them much slower
and more memory-hungry than they need to be: for instance, on my machine
Data.List.sum [1..10000000] takes over 15 minutes and uses half my RAM,
whereas foldl' (+) 0 [1..10000000] completes in only a few seconds and
uses less than 10% of my RAM.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4507>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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