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{-# OPTIONS_GHC -dcore-lint #-}
{-# OPTIONS_GHC -fplugin EmitWantedPlugin #-}
module TcPlugin_EmitWanted where
import Definitions
( MyClass(methC) )
foo :: MyClass a => a
foo = methC
bar :: Bool
bar = foo
-- We need to solve [W] MyClass a.
-- The plugin emits [W] a ~# (), and solves [W] MyClass a
-- using the coercion hole.
-- We then report an error for the unsolved a ~# () constraint,
-- where we get to see whether the source location of the newly
-- emitted Wanted constraint is as expected.
--
-- The crucial thing is that the error message should have
-- the correct SrcSpan, in this case line 13 column 7.
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