[GHC] #9360: GHCi: Behave nicely on `-e`, like `ghc` and other programs

[GHC]

#9360: GHCi: Behave nicely on `-e`, like `ghc` and other programs
-------------------------------------+-------------------------------------
       Reporter:  mcandre            |                   Owner:
           Type:  feature request    |                  Status:  new
       Priority:  normal             |               Milestone:
      Component:  Compiler           |                 Version:  7.8.2
       Keywords:                     |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Unknown            |         Type of failure:
     Blocked By:                     |  None/Unknown
Related Tickets:                     |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
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 Like many programming language environments, GHC offers a handy `-e`
 option for evaluating an expression, then returning to the shell.

 {{{
 $ ghc -e '2 + 2'

 4
 }}}

 One would expect the interpreter, GHCi, to offer a similar flag, but it
 surprisingly rejects it.

 {{{
 ghci -e '2 + 2'

 ghc: on the commandline: cannot use `--interactive' with `-e'

 Usage: For basic information, try the `--help' option.
 }}}

 I think this behavior is quite unintuitive--when I pass `-e <exp>` to
 ghci, or pass `--interactive -e <exp>` to ghc, I expect the expression to
 be evaluated as the leading expression in an interactive interpreter
 session.

 Could we please tweak ghc like this to make it slightly more intuitive
 when these flags are used together?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9360>
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