[GHC] #11529: Show instance of Char should print literals for non-ascii printable charcters

[GHC]

#11529: Show instance of Char should print literals for non-ascii printable
charcters
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        Reporter:  nushio            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 Absolutely any code in the entire world that relies on the current
 behavior will break. The current behavior is expressed in the reference
 implementation in the Haskell 2010 report. Frankly, changing it ''is not
 an option''. You can write your own function to unescape valid Unicode.
 You can also write your own `UShow` class if you like with a method for
 showing various things using Unicode generally. You can then try to
 convince other developers to depend on your package and write instances of
 your class.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11529#comment:2>
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