diff options
Diffstat (limited to 'libraries/base/GHC/List.hs')
| -rw-r--r-- | libraries/base/GHC/List.hs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libraries/base/GHC/List.hs b/libraries/base/GHC/List.hs index 8f03ce3a08..d9b32ea9df 100644 --- a/libraries/base/GHC/List.hs +++ b/libraries/base/GHC/List.hs @@ -1128,12 +1128,16 @@ zipWith3FB cons func = \a b c r -> (func a b c) `cons` r -- and a list of second components. unzip :: [(a,b)] -> ([a],[b]) {-# INLINE unzip #-} +-- Inline so that fusion `foldr` has an opportunity to fire. +-- See Note [Inline @unzipN@ functions] in GHC/OldList.hs. unzip = foldr (\(a,b) ~(as,bs) -> (a:as,b:bs)) ([],[]) -- | The 'unzip3' function takes a list of triples and returns three -- lists, analogous to 'unzip'. unzip3 :: [(a,b,c)] -> ([a],[b],[c]) {-# INLINE unzip3 #-} +-- Inline so that fusion `foldr` has an opportunity to fire. +-- See Note [Inline @unzipN@ functions] in GHC/OldList.hs. unzip3 = foldr (\(a,b,c) ~(as,bs,cs) -> (a:as,b:bs,c:cs)) ([],[],[]) |