[GHC] #13450: Better parse error for empy character literal

[GHC]

#13450: Better parse error for empy character literal
-------------------------------------+-------------------------------------
        Reporter:  parsonsmatt       |                Owner:  (none)
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
  (Parser)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Poor/confusing    |            Test Case:
  error message                      |  parser/should_fail/T13450
                                     |  parser/should_fail/T13450TH
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4594
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"cac8be611e7e80ed80e24b15faac9e1ac0a07247/ghc" cac8be6/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="cac8be611e7e80ed80e24b15faac9e1ac0a07247"
 Better error message for empty character literal, for Trac #13450.

 For empty character literal, the `''`, report error message properly
 rather than just throw a "parser error" with wrong error location.

 Test Plan: make test TEST="T13450 T13450TH"

 Reviewers: goldfire, bgamari

 Reviewed By: bgamari

 Subscribers: thomie, mpickering, carter

 GHC Trac Issues: #13450

 Differential Revision: https://phabricator.haskell.org/D4594
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13450#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler