[GHC] #2362: allow full import syntax in GHCi

[GHC]

#2362: allow full import syntax in GHCi
---------------------------------+------------------------------------------
    Reporter:  Isaac Dupree      |        Owner:  igloo       
        Type:  feature request   |       Status:  new         
    Priority:  high              |    Milestone:  6.14.1      
   Component:  Compiler          |      Version:  6.8.2       
    Keywords:  ghci, import      |   Difficulty:  Unknown     
          Os:  Unknown/Multiple  |     Testcase:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
---------------------------------+------------------------------------------
Changes (by SamAnklesaria):

  * owner:  SamAnklesaria => igloo


Comment:

 My patch separates ghci 'import' syntax from ':module' syntax: while
 ':module' behaves the same way it always has (not allowing full import
 syntax), 'import' now acts like the full haskell98 'import'. This means,
 however, that starred module name imports (that is, full top levels) are
 now not supported by 'import'. With ':module' still supporting this,
 though, I don't think this is a problem.

 Because import commands are represented by ImportDecls, I modified the
 "ic_exports" field of InteractiveContext to take both modules and their
 corresponding import declarations, if any.  Along with this change comes a
 modification of getContext, which must use the different "ic_exports"
 type.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2362#comment:17>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler