[GHC] #9767: Add isSubsequenceOf to Data.List

[GHC]

#9767: Add isSubsequenceOf to Data.List
-------------------------------------+-------------------------------------
       Reporter:  bernalex           |                   Owner:
           Type:  feature request    |                  Status:  new
       Priority:  normal             |               Milestone:  7.10.1
      Component:  libraries/base     |                 Version:  7.8.3
       Keywords:                     |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Easy (less than 1  |         Type of failure:
  hour)                              |  None/Unknown
     Blocked By:                     |               Test Case:
Related Tickets:                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
 Niklas Hambüchen suggested that we add the dual of subsequences,
 isSubsequenceOf (like isPrefixOf to inits & isSuffixOf to tails)[1]. It
 was a simple and noncontroversial proposal which received unanimous +1s.

 [1]
   https://www.haskell.org/pipermail/libraries/2014-November/024063.html

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9767>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler