[Haskell-cafe] Why were datatype contexts removed instead of "fixing them"?

[gs]

Brandon Allbery <allbery.b <at> gmail.com> writes:

> ... which means that implementers should be free to "fix" data type contexts
> however they like, as they are now complier extensions which won't conflict
> with standard Haskell.
> 
> Except that people do build older programs with newer Haskell compilers,
and it's bad to "repurpose" a syntax like that because it leads to strange
errors.

"Remembering" data type contexts shouldn't break existing code, unless it's
semantically broken already. (I'm sure that anyone could come up with a
theoretical example of code which would break - but would it break any
real-world code?)