io-classes: MonadMaskingState inconvenient

[dcoutts]

It is unclear to me why MonadMaskingState is separate from MonadMask. Is there some good reason?

It is a bit inconvenient, when one is already using MonadMask and then wanting to use one of the other masking-related functions and having to propagate a new class constraint everywhere.

And related: why does MonadEvaluate inherit from MonadThrow? I can't see how they are related.

[coot]

You're right that this is a bit artificial. My motivation was to keep the lower-level stuff visible in types.

MonadEvaluate: indeed, MonadThrow can be removed.