Expose notNull so that a _NotNull prism can be made.

[dkoontz]

I was trying to construct a prism for Nullable JS data and exposing notNull seemed the most straightforward way to get the right type. This also give future users a prism to use.

[paf31]

Wouldn't this need to go into bower.json?

[paf31]

What about making this an Iso between Nullable and Maybe. Then you can reuse _Just, and you don't need to export notNull, which I think has a slightly confusing name.

[dkoontz]

Quite right about the bower dependency. I've never used Iso so I'll look into that.

[paf31]

Bump

[dkoontz]

Is this the kind of thing you were thinking? The Prism can be defined separately in terms of isoNullableMaybe or were you saying to do this and also add the Prism?

[paf31]

@dkoontz Sorry, no, I was referring to this Iso, the one from profunctor-lenses. That way, it would be compatible with other types of optics.

[dkoontz]

Sorry I'm not following, if notNull is not exported how would I create the Iso in a separate module? Do you want the Iso declaration in Data.Nullable

[paf31]

Do you want the Iso declaration in Data.Nullable

Yes please. Something like

import Data.Profunctor

isoToMaybe :: forall p a b. Profunctor p => p (Nullable a) (Nullable b) -> p (Maybe a) (Maybe b)
isoToMaybe = dimap toNullable toMaybe 

By using profunctors, we don't need to add the dependency on profunctor-lenses.

[paf31]

Since this is now a bit different from the proposal, I'll close it and make an issue instead. Thanks anyway!