Simon Peyton Jones pushed to branch wip/T23162-part2 at Glasgow Haskell Compiler / GHC
Commits:
-
0432673b
by Simon Peyton Jones at 2025-12-19T08:31:15+00:00
1 changed file:
Changes:
| ... | ... | @@ -42,6 +42,13 @@ Compiler |
| 42 | 42 | bound to variables. The very similar pattern ``Foo{bar = Bar{baz = 42}}``
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| 43 | 43 | will will not yet mark ``bar`` or ``baz`` as covered.
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| 44 | 44 | |
| 45 | +- GHC uses the information from the definition of a *closed* type family to
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| 46 | + generate some extra functional dependencies for type equalities involving
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| 47 | + that type family. As a consequence:
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| 48 | + |
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| 49 | + * typechecking will succeed a bit more often (see :ghc-ticket:`23162`)
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| 50 | + * pattern-match incompleteness checking is a bit smarter, giving fewer false warnings (see :ghc-ticket:`#22652`)
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| 51 | + |
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| 45 | 52 | - When multiple ``-msse*`` flags are given, the maximum version takes effect.
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| 46 | 53 | For example, ``-msse4.2 -msse2`` is now equivalent to ``-msse4.2``.
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| 47 | 54 | Previously, only the last flag took effect.
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