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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 | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/docs/users_guide/8.12.1-notes.rst b/docs/users_guide/8.12.1-notes.rst index 22b9e0b571..bc8450417f 100644 --- a/docs/users_guide/8.12.1-notes.rst +++ b/docs/users_guide/8.12.1-notes.rst @@ -19,6 +19,19 @@ Highlights In the mean this improved runtime by about 0.8%. For details see ticket :ghc-ticket:`17823`. +* Pattern-Match Coverage Checking + + - The revamp of the pattern-match coverage checker that started in 8.10 concludes with this release and implements the + novel `*Lower Your Guards* <https://www.microsoft.com/en-us/research/uploads/prod/2020/03/lyg.pdf>`_ algorithm. + - Compared to 8.10, end users might notice improvements to "long-distance information": :: haskell + + :linenos: + f True = 1 + f x = ... case x of { False -> 2; True -> 3 } ... + + GHC is now able to detect the case alt returning 3 as redundant. + - Some more performance improvements in edge cases. + Full details ------------ |