I’m trying to do something similar to wath ecto does when defining schemas. Basically the idea is:

defmodule Test do
  use TableBuilder

  row "test" do
    field "field1"
    field "field2"
  end
end

row and field are macros defined in the TableBuilder module, what I’m trying to achieve is a DSL that underneath builds a Row struct, that has a fields collection of Field structs

here is what I’m doing right now:

defmodule TableBuilder do
  defmacro __using__(_opts) do
    quote do
      import unquote(__MODULE__)
      Module.register_attribute __MODULE__, :rows, accumulate: true
      @before_compile unquote(__MODULE__)
    end
  end

  defmacro __before_compile__(_env) do
    quote do
      def get_table do
        inspect @rows
      end
    end
  end

  defmacro row(name, do: fields) do
    row = %Row{name: name}
    quote do
      @rows {unquote(row), unquote(fields)}
    end
  end

  defmacro field(name) do
    quote do
      %Field{name: unquote(name)}
    end
  end
end

the problem is:

when the field macro is called, I need to access the row variable created in the row macro.
But I can’t find a solution.

What’s the problem with this approach? Am I doing it wrong? Do you see better approaches to the problem?

Many thanks in advance!