RE: VariantLens

[erlandsona]

2 thoughts

1. rename: VariantLens.GenerateUsed -> NoMissingVariantPrism a. One because in Optics terms "Lenses" don't operate over Sum types / ADT's only "Product Types" aka records. Prisms operate over Sums/ADTS/Variants... b. To match better with NoMissingRecordFieldLens 🤷‍♂️

2. Generate Prisms inline below the definition of the Variant to not force the defining module to expose its constructors. EG: I'd like to "expose" some lenses for operating over say pieces of an otherwise opaque record... something like...

module OpaqueThing exposing (Stuff, current)

type Stuff = Stuff Internal
-- generated opaque Prism constructor for composing helpers for accessing pieces of internal state.
onStuff : Lens Stuff Internal reach wrap
onStuff  = -- ...

type alias Internal = 
    { current_ : String
    , toggle : Bool  -- Notice callers have no access to this toggle property.
    } 

current : Lens Stuff String reach wrap
current = onStuff << Lens.current_

[lue-bird]

• renaming variant lens to prism
  • approve
  • i didn't know terminology better then
  • i've added this to plans for the next breaking version
• GenerateUsed is slightly more clear than NoMissing IMO (best would be GenerateMissingUsed or sth)
• internal prism reference
  • good idea
  • are you motivated to implement and integrate this yourself? Otherwise, you might have to wait some time, sorry
  • i've added this to plans for the next breaking version

[erlandsona]

internal prism reference is a good idea are you motivated to implement this yourself? Otherwise, you might have to wait some time, sorry

It's what I had in the original PR see here for how I had implemented it before. https://github.com/lue-bird/elm-review-missing-record-field-lens/pull/2/files#diff-51ee51156bc0e70de37a9487fc4867daf98cb8a198b9d400d5cb974889677868

[lue-bird]

done, published