Invalid behaviour of `Pathex.delete!` when using concatenation and/or `all` lense about pathex

[hissssst]

Yeah, there was a tiny typo in concat.ex

But you're kinda misusing the library. all() lens works in an eager-style evaluation. Therefore. this lens either deletes all the values, or returns an error. For example,

delete(list, all() ~> path("a"))

returns{:ok, []} if all elements of the list have "a" as a key or :error.

To work with a more lazy-style evalutation I'd suggest using star() lens. And I think, your deep_dive_path should be implemented using star lens.

[hissssst]

@ffloyd , you can use version 2.4.1

[ffloyd]

Thank you! I am impressed with how fast you reacted! Appreciate it!

I checked the behavior for the updated version. With the star/0 lens everything works as expected. But I still see some weird behavior with all/0 lens:

import Pathex

data = [
  %{ "a" => 1 },
  %{ "a" => 2 }
]

all_a = Pathex.Lenses.all() ~> path("a")

Pathex.get(data, all_a) |> IO.inspect(label: "get")
Pathex.delete!(data, all_a) |> IO.inspect(label: "delete!")

And as result get/2 works, but delete/2 fails:

** (Pathex.Error) 
  Couldn't find element

    Path:      all() ~> path("a")

    Structure: [%{"a" => 1}, %{"a" => 2}]

    (stdlib 3.17.2) erl_eval.erl:685: :erl_eval.do_apply/6
    (stdlib 3.17.2) erl_eval.erl:893: :erl_eval.expr_list/6
    (stdlib 3.17.2) erl_eval.erl:408: :erl_eval.expr/5
    (elixir 1.14.0) lib/module/parallel_checker.ex:100: Module.ParallelChecker.verify/1

[hissssst]

Yeah, looks like a bug in concatenation of delete operation

[hissssst]

@ffloyd , opened #21 to track the issue