[Haddock] vim help text export

[David Waern]

2012/1/15 Simon Hengel <sol at typeful.net>:
> Wouldn't it be neat to write one "backend" that produces an AST, lets
> call it HaddockCore for now.  Than we could provide a catamorphism for
> that, and writing a backend would just be folding over that AST.

I think what we want is to simply provide a file that contains
everything Haddock knows about a package that could be useful to a
backend writer. Different backends do different things and not all can
be seen as folding over an AST.

There are some open questions to such a plan however:

  * Should the file contain *everything* or should users combine it
with information from .hi files?
    For example, should we put declarations in the file or should
users recover them from .hi files?

  * Should it be a text file or a binary file? (I.e. should we invent
a new format or should it be the .haddock file).

David