> Here's a proposal for an alternative without parameter docstrings and
> a
> different DSL (see os_stat.c). I guess it's easiest to present my
> thoughts
> in list form.

It's a bit difficult to give an opinion without a more formal definition.
For example it seems you are using REQUIRED and KEYWORD as opposites,
but a required argument can also be a keyword argument.

As for the docstring: I would like it better if I could avoid typing
the cumbersome "\n\"s.

As for the general parameter declaration syntax: I think it shouldn't
be too verbose, otherwise it will quickly become tiring.
(also I don't think it should be required to write "[preprocessor]"
twice)