[GHC] #3464: Find import declaration importing a certain function

[GHC]

#3464: Find import declaration importing a certain function
---------------------------------+------------------------------------------
    Reporter:  fasta             |        Owner:              
        Type:  feature request   |       Status:  new         
    Priority:  normal            |    Milestone:  7.0.1       
   Component:  GHCi              |      Version:  6.10.4      
    Keywords:                    |     Testcase:              
   Blockedby:                    |   Difficulty:  Unknown     
          Os:  Unknown/Multiple  |     Blocking:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
---------------------------------+------------------------------------------
Changes (by claus):

  * failure:  => None/Unknown


Comment:

 Until you find someone to implement this feature properly, there is a
 workaround.

 Using the GHCi script `redir.script`, attached to #4332, you can capture
 the output of `:browse!`.

 `:browse!` extends `:browse` by including information about import paths
 in comments, so we can filter for lines with comments or the identifier in
 question to get the info you're after:
 {{{
 *ModMain> :redir output :browse! *ModMain
 *ModMain> putStrLn $ unlines $ filter ((`elem`["--","map"]).head.words) $
 lines output
 -- imported via ModC, ModB, Prelude
 map :: (a -> b) -> [a] -> [b]
 -- imported via Prelude
 }}}
 Once we have the right incantation, we can define another GHCi command for
 this (normally, I'd use regexes, but they are broken in GHC head right
 now).

 Hope this helps

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3464#comment:5>
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