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| author | Andreas Klebinger <klebinger.andreas@gmx.at> | 2021-12-14 19:24:20 +0100 |
|---|---|---|
| committer | Andreas Klebinger <klebinger.andreas@gmx.at> | 2021-12-14 19:24:20 +0100 |
| commit | c43ee6b81bd544ae338f9287a7b1edb646d51531 (patch) | |
| tree | c66d5fbb9e8a3c1ada6014f3b3135c21f3419103 | |
| parent | 401ddd5300c8be2ee03bf040146e7f2878bae0a9 (diff) | |
| download | haskell-c43ee6b81bd544ae338f9287a7b1edb646d51531.tar.gz | |
GHC.Utils.Misc.only: Add doc string.
This function expects a singleton list as argument but only checks this
in debug builds. I've added a docstring saying so.
Fixes #20797
| -rw-r--r-- | compiler/GHC/Utils/Misc.hs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/compiler/GHC/Utils/Misc.hs b/compiler/GHC/Utils/Misc.hs index fbf52d1bdb..29cad99cd3 100644 --- a/compiler/GHC/Utils/Misc.hs +++ b/compiler/GHC/Utils/Misc.hs @@ -493,6 +493,10 @@ isSingleton _ = False notNull :: Foldable f => f a -> Bool notNull = not . null +-- | Utility function to go from a singleton list to it's element. +-- +-- Wether or not the argument is a singleton list is only checked +-- in debug builds. only :: [a] -> a #if defined(DEBUG) only [a] = a |