[GHC] #12139: Add TUI (text-based user interface) for GHCi

[GHC]

#12139: Add TUI (text-based user interface) for GHCi
-------------------------------------+-------------------------------------
           Reporter:  siddhanathan   |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  low            |         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:
-------------------------------------+-------------------------------------
 GDB has a really nice TUI mode:
 https://upload.wikimedia.org/wikipedia/commons/4/47/GDB_TUI.png

 It's a curses interface which highlights the line number you're on, and
 also shows the surrounding lines.

 GHCi currently allows stepping through with the `:step` command, which
 displays line and column numbers. It would be nice to have some visual
 indication along with these numbers.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12139>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler