Suggest to use the where keyword for a typeclass instance when it's missing
Motivation
When I forget to add the where keyword when I create a typeclass instance I get a confusing error message.
module Example where
instance Show
show = undefined
> [14 of 15] Compiling Example
>
> project/src/Example.hs:4:8: error: parse error on input ‘=’
> |
> 4 | show = undefined
Proposal
Describe your proposed feature here.
I think the error message could be improved by suggesting that I may have missed the where keyword.
For example:
> [14 of 15] Compiling Example
>
> project/src/Example.hs:4:8: error: parse error on input ‘=’
> |
> 4 | show = undefined
Perhaps you meant:
instance Show where
show = undefined