[GHC] #8081: let form in do block requires in?

GHC ghc-devs at haskell.org
Mon Jul 22 12:40:34 CEST 2013


#8081: let form in do block requires in?
----------------------------------------------+----------------------------
        Reporter:  dsamperi                   |            Owner:
            Type:  bug                        |           Status:  closed
        Priority:  normal                     |        Milestone:
       Component:  Compiler                   |          Version:  7.6.3
      Resolution:  invalid                    |         Keywords:
Operating System:  Linux                      |     Architecture:  x86_64
 Type of failure:  GHC rejects valid program  |  (amd64)
       Test Case:                             |       Difficulty:  Unknown
        Blocking:                             |       Blocked By:
                                              |  Related Tickets:
----------------------------------------------+----------------------------
Changes (by igloo):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 Thanks for the report. However, the problem isn't that `in` is needed, but
 is due to the implicit layout for the `let` not behaving as you expect. If
 you use explicit layout for the `let` too then it is accepted:
 {{{
 do1 = do { let { x = 3.14 } ; return x }
 }}}
 You can also use implicit layout if you lay the code out differently:
 {{{
 do1 = do let x = 3.14
          return x
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8081#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler




More information about the ghc-tickets mailing list