[Hackage] #369: Version ranges should be simplified before printing

[Hackage]

#369: Version ranges should be simplified before printing
----------------------------+-----------------------------------------------
  Reporter:  nominolo       |        Owner:        
      Type:  defect         |       Status:  new   
  Priority:  normal         |    Milestone:        
 Component:  Cabal library  |      Version:  HEAD  
  Severity:  minor          |   Resolution:        
  Keywords:                 |   Difficulty:  normal
Ghcversion:  6.9            |     Platform:        
----------------------------+-----------------------------------------------
Changes (by duncan):

  * summary:  Version range printing is inconsistent => Version ranges
              should be simplified before printing

Comment:

 If we look at `scion.cabal` we find (simplified):

 {{{
 executable test
   build-depends: base >= 4 && < 5,
                  ghc-paths >= 0.1 && < 0.2,
                  ghc >= 6.10 && < 6.12

 executable test_get_imports
   build-depends: base >= 4 && < 5,
                  ghc-paths >= 0.1 && < 0.2,
                  ghc >= 6.10 && < 6.12,
                  ghc-syb >= 0.1 && < 0.2,
                  directory >= 1.0 && < 1.1
 }}}

 Note that `ghc-paths >= 0.1 && < 0.2` is mentioned in both executable
 stanzas. The dependencies of the package as a whole are the combination of
 the dependencies of each stanza.

 It may be sensible for complexity of presentation purposes to simplify
 version ranges. We could add a function
 {{{
 VersionRange.simplify :: VersionRange -> VersionRange
 }}}
 which should satisfy the property
 {{{
 forall vr v. eval (simplify vr) v == eval vr v

   where eval = flip withinRange
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/369#comment:2>
Hackage <http://haskell.org/cabal/>
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