how to remove too much map_error ?

[lost22git]

let assert Ok(r) = 
      response.body
      |> json.decode(dynamic.dict(of: dynamic.string, to: dynamic.dynamic))
      |> result.map_error(fn(e) { hackney.Other(dynamic.from(e)) })
      |> result.then(fn(it) {
        it
        |> dict.get("json")
        |> result.map_error(fn(e) { hackney.Other(dynamic.from(e)) })
      })
      |> result.then(fn(it) {
        it
        |> dynamic.dict(dynamic.string, dynamic.dynamic)
        |> result.map_error(fn(e) { hackney.Other(dynamic.from(e)) })
      })

[lost22git]

are there anyhow ?

[lpil]

You could use one decoder instead of doing it in steps:

response.body
|> json.decode(dynamic.field("json", of: dynamic.string)
|> result.map_error(fn(e) { hackney.Other(dynamic.from(e)) })

You could also make your error type more precise by not using Dynamic. This would make it more concise and also easier to work with. It's very rare that you should have a Dynamic from anywhere but user input.

response.body
|> json.decode(dynamic.field("json", of: dynamic.string)
|> result.map_error(JsonError)

[lost22git]

It would be great if there was something like this:

something from crystal:

json_any.dig("a", "b", 0, "c").as_s

[lpil]

You could make a dig function in Gleam very easily, just list.try_fold over the path with dynamic.field.

The equivalent code in Crystal is this, which is more verbose:

begin
  json_any.dig("a", "b", 0, "c").as_s
rescue ex: JsonDecodeError
  raise JsonError(ex)
end