Commit 2722f202 authored by simonpj's avatar simonpj
Browse files

Update output and add -fallow-undecidable-instances where necesssary

parent 20634722
{-# OPTIONS -fglasgow-exts #-}
{-# OPTIONS -fglasgow-exts -fallow-undecidable-instances #-}
-- -fallow-undecidable-instances now needed because the Coverage Condition fails
module ShouldFail where
......
tcfail108.hs:7:0:
Non-type variables, or repeated type variables,
in the constraint: Eq (f (Rec f))
(Use -fallow-undecidable-instances to permit this)
Non-type variable argument in the constraint: Eq (f (Rec f))
(Use -fglasgow-exts to permit this)
In the context: (Eq (f (Rec f)))
While checking the context of an instance declaration
In the instance declaration for `Eq (Rec f)'
{-# OPTIONS -fglasgow-exts #-}
{-# OPTIONS -fglasgow-exts -fallow-undecidable-instances #-}
-- -fallow-undecidable-instances because (L a b) is no smaller than (C a b)
-- This one shows up another rather subtle functional-dependecy
-- case. The error is:
......
tcfail138.hs:27:0:
tcfail138.hs:28:0:
Could not deduce (C a b') from the context (C a b)
arising from the superclasses of an instance declaration at tcfail138.hs:27:0
arising from the superclasses of an instance declaration at tcfail138.hs:28:0
Possible fix:
add (C a b') to the instance declaration superclass context
In the instance declaration for `C (Maybe a) a'
tcfail154.hs:12:0:
Non-type variables, or repeated type variables,
Variable occurs more often in a constraint than in the instance head
in the constraint: C a a
(Use -fallow-undecidable-instances to permit this)
In the context: (C a a)
While checking the context of an instance declaration
In the instance declaration for `Eq (T a)'
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment