[GHC] #12829: Multiline input (‘:set +m’) terminated by trailing whitespace

[GHC]

#12829: Multiline input (‘:set +m’) terminated by trailing whitespace
-------------------------------------+-------------------------------------
           Reporter:  Iceland_jack   |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  GHCi           |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 {{{
 $ ghci -ignore-dot-ghci
 GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
 Prelude> :set +m
 Prelude> let
 Prelude| a :: Int
 Prelude| a = 5
 Prelude|
 Prelude>
 }}}

 works fine with [https://downloads.haskell.org/~ghc/master/users-
 guide/ghci.html#multiline-input multiline input], but if you add one
 trailing space it immediately terminates the input

 {{{
 Prelude> let
 Prelude| a :: Int␣

 <interactive>:11:1: error:
     The type signature for ‘a’ lacks an accompanying binding
 }}}

 I don't know if this is the desired behavior but this means I can't
 copy/paste code into GHCi that has a trailing whitespace.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12829>
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