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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2015-03-04 11:59:47 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2015-03-04 12:00:21 +0000 |
| commit | f66e0e695b0377c469fbe877d4850fc0ebca2010 (patch) | |
| tree | f20d6e81e1d79e3e1d6e6cff923203e460f73d96 /testsuite/tests/typecheck/should_fail/tcfail150.stderr | |
| parent | d058bc9ce04e8397c8fd0a32a8654b83f3ef4af1 (diff) | |
| download | haskell-f66e0e695b0377c469fbe877d4850fc0ebca2010.tar.gz | |
A raft of small changes associated with -XConstrainedClassMethods
See Trac #7854. Specifically:
* Major clean up and simplification of check_op in checkValidClass;
specifically
- use checkValidType on the entire method-selector type to detect
ambiguity
- put a specific test for -XConstrainedClassMethods
* Make -XConstrainedClassMethods be implied by -XMultiParamTypeClasses
(a bit ad-hoc but see #7854), and document in the user manual.
* Do the checkAmbiguity test just once in TcValidity.checkValidType,
rather than repeatedly at every level. See Note [When to call checkAmbiguity]
* Add -XAllowAmbiguousTypes in GHC.IP, since 'ip' really is ambiguous.
(It's a rather magic function.)
* Improve location info for check_op in checkValidClass
* Update quite a few tests, which had genuinely-ambiguous class
method signatures. Some I fixed by making them unambiguous; some
by adding -XAllowAmbiguousTypes
Diffstat (limited to 'testsuite/tests/typecheck/should_fail/tcfail150.stderr')
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/tcfail150.stderr | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/tcfail150.stderr b/testsuite/tests/typecheck/should_fail/tcfail150.stderr index e69de29bb2..c91d404c13 100644 --- a/testsuite/tests/typecheck/should_fail/tcfail150.stderr +++ b/testsuite/tests/typecheck/should_fail/tcfail150.stderr @@ -0,0 +1,8 @@ +
+tcfail150.hs:6:3:
+ Constraint ‘Eq a’ in the type of ‘op’
+ constrains only the class type variables
+ Use ConstrainedClassMethods to allow it
+ When checking the class method:
+ op :: forall a. (Foo a, Eq a) => a -> a
+ In the class declaration for ‘Foo’
|