[GHC] #11170: (read ".9") :: Double unable to parse

[GHC]

#11170: (read ".9") :: Double unable to parse
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        Reporter:  varosi            |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Prelude           |              Version:  7.10.2
      Resolution:  invalid           |             Keywords:  Read
Operating System:  Windows           |         Architecture:  x86_64
 Type of failure:  Incorrect result  |  (amd64)
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by nomeata):

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


Comment:

 It actually is parseable, if you put parens around it:
 {{{#!hs
 > :t (.4)
 (.4) :: Num (a -> b) => (b -> c) -> a -> c
 }}}

 The problem here is that `.` is an operator, so it parses it as `\x -> (.)
 x 4` (which would type check if you have have an instance `Num (a -> b)`).
 This is the correct behaviour according to the language specification, and
 definitely nothing a compiler should do different.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11170#comment:1>
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