[GHC] #14812: Dot-Notation for Function Application

[GHC]

#14812: Dot-Notation for Function Application
-------------------------------------+-------------------------------------
           Reporter:  tepan          |             Owner:  (none)
               Type:  feature        |            Status:  new
  request                            |
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.2.2
           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:
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 Please allow to put a dot `.` (without spaces) between two things for
 ''flipped'' function application. This could make for code in pseudo-OOP
 style:

 {{{#!hs
 encrypt(str) = do {
   str.map(succ);
 }
 }}}

 Currently, as a workaround, this can be achieved by defining `(.) = flip
 ($)` (making `.` for function composition unavailable, though):

 {{{#!hs
 encrypt(str) = do {
   str.map(succ);
 } where (.) = flip ($)
 }}}

 (For a remotely similar look-and-feel, one could use `Data.Function.((&))`
 instead of `(.)`.)

 Please note that `.` without spaces is already an OOP-like notational
 convenience in order to denote Modules and their elements.

 {{{#!hs
 x = do {
   Prelude.length("Hello World!");
 }
 }}}

 This means, that a distinction between ` . ` (with spaces) and `.`
 (without spaces) is already been made, which is why `Just . Just $ 42`
 compiles, wheras `Just.Just $ 42` doesn't. Analogously, with this Feature
 Request implemented, `"Hello".map(succ)` would compile whereas `"Hello" .
 map(succ)"` wouldn't.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14812>
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