[GHC] #13699: Pretty printing: Strict record fields are not parenthesized properly

14 May 2017


      #13699: Pretty printing: Strict record fields are not parenthesized properly
-------------------------------------+-------------------------------------
           Reporter:  zyla           |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  low            |         Milestone:
          Component:  GHCi           |           Version:  8.0.1
           Keywords:  pretty-print   |  Operating System:  Unknown/Multiple
  bang record                        |
       Architecture:                 |   Type of failure:  Other
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 When I type in GHCi:

 {{{
 λ> data Foo = Foo { x :: !(Maybe Int) }
 λ> :i Foo
 data Foo = Foo {x :: !Maybe Int}        -- Defined at <interactive>:71:1
 }}}

 But this is not legal Haskell syntax:

 {{{
 λ> data Foo = Foo {x :: !Maybe Int}

 <interactive>:73:22: error:
     • Unexpected strictness annotation: !Maybe
     • In the type ‘!Maybe Int’
       In the definition of data constructor ‘Foo’
       In the data declaration for ‘Foo’
 }}}

 I think it should be pretty printed with parens:

 {{{
 λ> :i Foo
 data Foo = Foo {x :: !(Maybe Int)}        -- Defined at <interactive>:71:1
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13699
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler