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Diffstat (limited to 'testsuite/tests/typecheck/should_compile/T14488.hs')
| -rw-r--r-- | testsuite/tests/typecheck/should_compile/T14488.hs | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/T14488.hs b/testsuite/tests/typecheck/should_compile/T14488.hs new file mode 100644 index 0000000000..a4a12841b7 --- /dev/null +++ b/testsuite/tests/typecheck/should_compile/T14488.hs @@ -0,0 +1,10 @@ +{-# LANGUAGE RankNTypes #-} + +module T14488 where + +type Lens' s a = forall f. Functor f => (a -> f a) -> s -> f s + +data T a = MkT { _tfield :: Eq a => a } + +tfield :: Eq a => Lens' (T a) a +tfield f t = MkT <$> f (_tfield t) |