Hello all, recently this book came into my attention, namely I am trying to do a macro that creates a module dynamically. Let’s say, something like this:
defmodule Name do
@opaque t :: {:name, String.t()}
@spec new(val :: String.t()) :: t
def new(val) when is_binary(val), do: {:name, val}
@spec extract(name :: t) :: String.t()
def extract({:name, val}), do: val
@spec name?(data :: any) :: boolean()
def name?({:name, val}) when is_binary(val), do: true
def name?(_data), do: false
@spec is_name(data :: any) ::
{:__block__ | {:., [], [:andalso | :erlang, ...]}, [],
[{:= | {any, any, any}, [], [...]}, ...]}
defguard is_name(value)
when is_tuple(value) and elem(value, 0) == :name and is_binary(elem(value, 1))
end
which would be generated by invoking:
deftype Name, String.t()
Now I have checked the mini-video for the book:
And as an intro, it covers a lot. But after checking the index I have some questions:
- does the book cover my specific use case? (does it teach how to dynamically generate modules?)
- does the book cover how to include typespecs in the generated code?
- How many pages does the book have?
