Custom-environment DSL vs. require()

[Alexander Gladysh <agladysh@...>]

Hi, list!

I have some code, written in a Lua-based DSL, a lot of constructs like this:

foo:bar "title"
{
  baz = "quo";

  alpha:beta "gamma"
  {
    "delta";
  };
}

This code is executed inside a custom global environment with
pre-defined global objects foo and alpha (one can say these objects
implement Builder pattern — things are a bit more complicated in my
case, but that doesn't matter for this question).

After the code is run, I inspect foo and alpha variables, and get the
built data from them.

Now I want to move this code to the Lua module — to make it reusable
via require().

Obviously, I can't just require() the file with DSL — the environment
would be wrong.

This means that I have to put my DSL into a function:

local dsl_chunk = function()
  return foo:bar "title"
  {
    baz = "quo";

    alpha:beta "gamma"
    {
      "delta";
    };
  }
end

return
{
  dsl_chunk = dsl_chunk;
}

This works, but is less pretty. Also it affects the code that loads
the DSL: I have to handle require-friendly DSL files differently.

Perhaps there is some trick that I miss? I don't mind to add some
boilreplate code to the "library" portions of my DSL code. But I'd
like to keep that boilerplate to a bare minimum.

Alexander.