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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2015-06-25 15:48:37 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2015-06-25 15:49:39 +0100 |
| commit | 9a348640c5ddd63c3385d3722fb3ade38013a148 (patch) | |
| tree | 3ef2406dcec0d237380b2e278a69cbfefded8375 /testsuite/tests/deriving/should_compile | |
| parent | 4d1316a56cb2e763ef6b47f95e529ae799b4c5ff (diff) | |
| download | haskell-9a348640c5ddd63c3385d3722fb3ade38013a148.tar.gz | |
Improve kind-checking for 'deriving' clauses
The main payload is in 'mk_functor_like_constraints' in
TcDeriv.inferConstraints.
This is moving towards a fix for Trac #10561
Diffstat (limited to 'testsuite/tests/deriving/should_compile')
| -rw-r--r-- | testsuite/tests/deriving/should_compile/T10561.hs | 19 | ||||
| -rw-r--r-- | testsuite/tests/deriving/should_compile/T10561.stderr | 5 | ||||
| -rw-r--r-- | testsuite/tests/deriving/should_compile/all.T | 1 |
3 files changed, 25 insertions, 0 deletions
diff --git a/testsuite/tests/deriving/should_compile/T10561.hs b/testsuite/tests/deriving/should_compile/T10561.hs new file mode 100644 index 0000000000..85acc516d9 --- /dev/null +++ b/testsuite/tests/deriving/should_compile/T10561.hs @@ -0,0 +1,19 @@ +{-# LANGUAGE PolyKinds, DeriveFunctor, RankNTypes #-} + +module T10561 where + +-- Ultimately this should "Just Work", +-- but in GHC 7.10 it gave a Lint failure +-- For now (HEAD, Jun 2015) it gives a kind error message, +-- which is better than a crash + +newtype Compose f g a = Compose (f (g a)) deriving Functor + +{- +instance forall (f_ant :: k_ans -> *) + (g_anu :: * -> k_ans). + (Functor f_ant, Functor g_anu) => + Functor (Compose f_ant g_anu) where + fmap f_anv (T10561.Compose a1_anw) + = Compose (fmap (fmap f_anv) a1_anw) +-} diff --git a/testsuite/tests/deriving/should_compile/T10561.stderr b/testsuite/tests/deriving/should_compile/T10561.stderr new file mode 100644 index 0000000000..3a158ddb9a --- /dev/null +++ b/testsuite/tests/deriving/should_compile/T10561.stderr @@ -0,0 +1,5 @@ + +T10561.hs:10:52: error: + Couldn't match kind ‘k’ with ‘*’ + arising from the first field of ‘Compose’ (type ‘f (g a)’) + When deriving the instance for (Functor (Compose f g)) diff --git a/testsuite/tests/deriving/should_compile/all.T b/testsuite/tests/deriving/should_compile/all.T index e16d8f5432..a01a5149b2 100644 --- a/testsuite/tests/deriving/should_compile/all.T +++ b/testsuite/tests/deriving/should_compile/all.T @@ -53,4 +53,5 @@ test('T9069', normal, compile, ['']) test('T9359', normal, compile, ['']) test('T4896', normal, compile, ['']) test('T7947', extra_clean(['T7947a.o', 'T7947a.hi', 'T7947b.o', 'T7947b.hi']), multimod_compile, ['T7947', '-v0']) +test('T10561', normal, compile_fail, ['']) |