[GHC] #3984: Handle multiline input in GHCi history (was: interpret layout in GHCi)

[GHC]

#3984: Handle multiline input in GHCi history
-------------------------------+--------------------------------------------
  Reporter:  aavogt            |          Owner:                  
      Type:  feature request   |         Status:  new             
  Priority:  normal            |      Milestone:  7.4.1           
 Component:  GHCi              |        Version:  6.12.1          
Resolution:                    |       Keywords:                  
        Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
   Failure:  None/Unknown      |     Difficulty:                  
  Testcase:                    |      Blockedby:                  
  Blocking:                    |        Related:                  
-------------------------------+--------------------------------------------

Old description:

> This should work instead of needing '''{;}''' :
>
> {{{
> :{
> let f = do
>       one
>       two
>       three
> :}
> }}}
>
> Also the up arrow key should bring back the whole block (and allow
> navigating within it), skipping to the next or previous block or command
> when going past the ''':}''' or ''':{'''.

New description:

 GHCi accepts multiline input in the form of:

 {{{
 Prelude> :{
 Prelude|   let f = do
 Prelude|         print "Hello"
 Prelude|         print "World"
 Prelude|   :}
 }}}

 OR of the form:

 {{{
 Prelude> :set +m
 Prelude|   let f = do
 Prelude|             print "Hello"
 Prelude|             print "World"
 Prelude|
 Prelude>
 }}}

 However, recalling mulitline input from history (with the <Up> key or
 <C-p>) recalls it as its individual lines, not the whole input. Ideally
 multiline should be one history entry and allow proper editing of the
 recalled text.

--

Comment(by dterei):

 Edited ticket to reflect actual work needing to be done.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3984#comment:15>
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