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Diffstat (limited to 'docs/users_guide/8.12.1-notes.rst')
| -rw-r--r-- | docs/users_guide/8.12.1-notes.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/docs/users_guide/8.12.1-notes.rst b/docs/users_guide/8.12.1-notes.rst index eb72ca9bde..b15302a78d 100644 --- a/docs/users_guide/8.12.1-notes.rst +++ b/docs/users_guide/8.12.1-notes.rst @@ -86,6 +86,13 @@ Language This change prepares the way for Quick Look impredicativity. +* GHC now implements simplified subsumption, as described in `GHC Proposal #287 <https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0287-simplify-subsumption.rst>`__. + This change simplifies the type system, and prevents the possiblity of GHC + silently changing the semantics of user programs, but it does mean that some libraries + may need eta-expansion to typecheck. More info here: :ref:`simple-subsumption`. + + This change also prepares the way for Quick Look impredicativity. + * GHC now allows users to manually define the specificity of type variable binders. By marking a variable with braces ``{tyvar}`` or ``{tyvar :: kind}``, it becomes inferred despite appearing in a type signature. This feature |