[GHC] #7146: Literal strings printed wrong

[GHC]

#7146: Literal strings printed wrong
-------------------------------+--------------------------------------------
  Reporter:  simonpj           |          Owner:                  
      Type:  bug               |         Status:  closed          
  Priority:  normal            |      Milestone:                  
 Component:  Compiler          |        Version:  7.4.2           
Resolution:  fixed             |       Keywords:                  
        Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
   Failure:  None/Unknown      |     Difficulty:  Unknown         
  Testcase:                    |      Blockedby:                  
  Blocking:                    |        Related:                  
-------------------------------+--------------------------------------------
Changes (by simonpj):

  * status:  new => closed
  * resolution:  => fixed


Comment:

 Fixed by
 {{{
 commit 6fb7bf8c9ba2a53d718a0d2a5f9e0f78cb7faf8f
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Wed Aug 15 14:23:22 2012 +0100

     Fix Trac #7146, by displaying a "\n" in a multi-line string

 >---------------------------------------------------------------

  GHC/Show.lhs |    4 ++--
  1 files changed, 2 insertions(+), 2 deletions(-)

 diff --git a/GHC/Show.lhs b/GHC/Show.lhs index e3148cd..859c2fe 100644
 --- a/GHC/Show.lhs
 +++ b/GHC/Show.lhs
 @@ -390,12 +390,12 @@ showMultiLineString :: String -> [String]
  --   * break the string into multiple lines
  --   * wrap the entire thing in double quotes
  -- Example:  @showMultiLineString "hello\ngoodbye\nblah"@
 --- returns   @["\"hello\\", "\\goodbye\\", "\\blah\""]@
 +-- returns   @["\"hello\\n\\", "\\goodbye\n\\", "\\blah\""]@
  showMultiLineString str
    = go '\"' str
    where
      go ch s = case break (== '\n') s of
 -                (l, _:s'@(_:_)) -> (ch : showLitString l "\\") : go '\\'
 s'
 +                (l, _:s'@(_:_)) -> (ch : showLitString l "\\n\\") : go
 '\\' s'
                  (l, _)          -> [ch : showLitString l "\""]

  isDec :: Char -> Bool
 }}}
 There are a couple of testsuite stdout-changes in consequence, so I'm not
 making another test.

 I'm not sure this is worth merging.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7146#comment:1>
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