-----------------------------------------------------------------------------
-- bugs

* The lexer should handle "...." in doc strings, only recognising it if the
  contents looks like a module name.

* Mentioning a qualified identifer in doc loses the qualifier, even when
  it is required?  (see "[Haskell] auto-qualification of identifiers in
  Haddock").

* doc --gen-contents and --use-contents

* A module re-export should only reference the target module if the
  target module is imported without hiding any of its exports (otherwise
  we should inline just the exported bits).

* remove the s/r conflicts I added to the grammar

* Support for the rest of GHC extensions in the parser:
  - scoped type variables (return types left to do).
  - template haskell
  - explicit kind annotations
  - infix type constructors

* Be a bit cleaner about error cases: some internal errors can be
  generated by bugs in the Haskell source.  Divide out the proper
  internal error cases and emit proper error messages.

* derived instance support isn't quite right (doing it properly is 
  hard, though).

* Referring to something that has a defn but no type signature doesn't
  elicit a useful message.

* The synopsis generated for a module with no docs should not attempt to
  link to the doc for each entity.  We need a different kind of summary
  here: what we really want is just the documentation section but without
  the extra whitespace between decls.

* We don't handle non-ASCII characters in doc comments.  (need to specify
  the encoding in the generated HTML too?).

* There's no way to refer explicitly to either a type/class
  constructor or data constructor When there are more than one of
  these with the same name.  Perhaps introduce a special syntax for
  them?  (eg. ':C' means data constructor C?)

-----------------------------------------------------------------------------
-- features

* Have a short description for a module, which is presented by the module
  name in the contents? (idea from George Russell).

* In theory there's no reason why we have to only link to modules which
  are imported by the current module.  This is an artificial
  restriction.  We might try doing a two-pass strategy: first find out
  what everything exports, and then resolve all the links in the
  documentation.  We could mark some modules as "definitive" destinations
  for links to their entities, or even give a priority for each module.

* nested itemized and enumerated lists.

* There ought to be a way to include some structure in the "description"
  (section headings, etc.) and possibly in other comments.  (suggseted
  by Daan).

* Comments on instance declarations?  (suggested by Daan and Iavor).

* Comments on default method declarations?  (suggested by Satnam).

* Add a search feature which just invokes Google?

* Do the unlitting/CPPing from Haddock itself so we get the source file
  links right.

* attributes for individual declarations, eg.
    -- #abstract
  or targetted to a specific decl:
    -- #T: abstract

  #long, #short, #noinstances (on a type or class)

  #inline, #noinline on a module export

* Allow documentation annotations to explicitly name the entity they
  refer to.

* In the contents page, indicate portability/stability of each module
  somehow.

* Add back-references from the definition to the uses of types/classes
  (perhaps in the index?)

* Add a link to the defining location of a re-exported entity

* fixities

* include file revision info in module headers

* Allow individual function arguments to be documented when the function
  type is a record element?

* hiding instances?

* Add a way to indicate DEPRECATED functions/types/modules?  Perhaps
  parse the GHC DEPRECATED pragma?

-----------------------------------------------------------------------------
-- cosmetic

* Allow more parts of the documentation to be squashed and expanded?

* for a constructor, don't fill its entire cell with a grey background.

* switch to longer rendering form for datatypes when necessary?

* remove extra whitespace from the generated HTML to save space