Herminio Torres
Posted on December 26, 2023
It would be best if you considered using Keyword.fetch!/2 and Keyword.get/3 for options to APIs.
Without options
defmodule MyApp do
def config(name, author \\ "Herminio Torres", description \\ "Description") do
%{
name: name,
author: author,
description: description
}
end
end
iex> MyApp.config
config/1 config/2 config/3
iex> MyApp.config("my_app")
%{
author: "Herminio Torres",
description: "Description",
name: "my_app"
}
iex> MyApp.config("my_app", "Change")
%{
author: "Change",
description: "Description",
name: "my_app"
}
- Creates a config function with many arities
- You must pass all parameters when you intend to change just the last default argument.
With Options
defmodule MyApp do
def config(opts) do
name = Keyword.fetch!(opts, :name)
author = Keyword.get(opts, :author, "Herminio Torres")
description = Keyword.get(opts, :description, "Description")
%{
name: name,
author: author,
description: description
}
end
end
iex> MyApp.config([])
** (KeyError) key :name not found in: []
(elixir 1.12.3) lib/keyword.ex:420: Keyword.fetch!/2
iex:3: MyApp.config/1
iex> MyApp.config([name: "my_app"])
%{
author: "Herminio Torres",
description: "Description",
name: "my_app"
}
iex> MyApp.config([name: "my_app", description: "Change"])
%{
author: "Herminio Torres",
description: "Change",
name: "my_app"
}
- The raised error leads you to which options are required
- Keyword lists make the arguments named
- Only one function arity is exposed
Awesome!
💖 💪 🙅 🚩
Herminio Torres
Posted on December 26, 2023
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