Re: [GHC] #14384: real numbers, digits after the decimal point - digits of precision

24 Oct 2017

      #14384: real numbers, digits after the decimal point - digits of precision
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        Reporter:  vanto             |                Owner:  (none)
            Type:  feature request   |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:  invalid           |             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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Changes (by hsyl20):

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

Comment:

 The feature already exists.

 {{{#!haskell
 {-# LANGUAGE DefaultSignatures #-}
 {-# LANGUAGE FlexibleInstances #-}

 import Text.Printf

 class MyPrint a where
    myshow :: a -> IO ()

    default myshow :: Show a => a -> IO ()
    myshow = print

 instance MyPrint [Char]
 instance MyPrint Int

 instance MyPrint Double where
    myshow d = printf "%.11e\n" d
 }}}

 {{{
...
:load MyPrint.hs
 [1 of 1] Compiling Main             ( MyPrint.hs, interpreted )
 Ok, 1 module loaded.
:set -interactive-print myshow
(16.0/0.00002)**2.1
 2.49166110385e12
 }}}
-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14384#comment:7
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