[GHC] #14357: Document deriving strategies fully

[GHC]

#14357: Document deriving strategies fully
-------------------------------------+-------------------------------------
           Reporter:  nomeata        |             Owner:  (none)
               Type:  task           |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Documentation  |           Version:  8.2.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 The users’ guide currently sais in the section on `DerivingStrategies`:

 > If an explicit deriving strategy is not given, GHC has an algorithm for
 determining how it will actually derive an instance. For brevity, the
 algorithm is omitted here. You can read the full algorithm at Wiki page.

 I think this is doing our users a disservice: They want to rely on the
 guide to have authorative, concise and clear information. The wiki page
 contains too much stuff that is confusing for users (Alternative syntax,
 rationales etc.)

 (Also, the link in the manual is wrong).

 Ryan, do you agree and are you available to put the relevant bits into the
 manual?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14357>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler