Feature request : integeration with a lens library

[fcabouat]

Hi,

Did you consider providing some integration with one or more lens libraries ?

https://github.com/tpoulsen/focus → they already have a "deflens" macro, that defines struct and lenses at the same time
https://github.com/obrok/lens → seems more feature complete

Thanx for your library !

[ejpcmac]

Hello @fcabouat!

Thank you for reminding me this functional concept, I didn’t know there was lens libraries in Elixir, that’s interesting for managing nested structures.

About your request and including more features in general: I have thought about handling Ecto as well, but finally I think it would be better if typed_struct remains a tiny library. Users not using Ecto or a lense library don’t need code related to these features. It would be better if they were in different packages. What I can add in typed_struct however is some plugin system to build upon. This way, if you wanted to define lenses for the keys of a typed struct, you could do something like this:

defmodule MyStruct do
  use TypedStruct

  # This would contain the define_lenses/? function.
  import LensPlugin

  typedstruct do
    plugin :define_lenses

    field :name, String.t()
    field :age, integer()
  end
end

I’ve thought of this API in 5 minutes, it could change but you get the idea. This way, users could define callbacks that would be called during the typed struct definition, accessing to its fields. I will open a separate issue for this plugin feature.

[ejpcmac]

You can now use TypedStruct 0.2.0 with typed_struct_lens.