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Diffstat (limited to 'docs/users_guide/7.12.1-notes.rst')
| -rw-r--r-- | docs/users_guide/7.12.1-notes.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/docs/users_guide/7.12.1-notes.rst b/docs/users_guide/7.12.1-notes.rst index dfc5bb361b..2e0ae6f18c 100644 --- a/docs/users_guide/7.12.1-notes.rst +++ b/docs/users_guide/7.12.1-notes.rst @@ -164,6 +164,12 @@ Compiler `MonadFail Proposal (MFP) <https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail>`__. +- Added the ``-fwarn-semigroup`` flag. When enabled, this + will issue a warning if a type is an instance of ``Monoid`` but not + ``Semigroup``, and when a custom definition ``(<>)`` is made. Fixing these + warnings makes sure the definition of ``Semigroup`` as a superclass of + ``Monoid`` does not break any code. + GHCi ~~~~ |