[GHC] #7157: 'let' keyword optional in do notation

[GHC]

#7157: 'let' keyword optional in do notation
------------------------------+---------------------------------------------
 Reporter:  Oblosys           |          Owner:                  
     Type:  feature request   |         Status:  new             
 Priority:  normal            |      Component:  Compiler        
  Version:  7.6.1-rc1         |       Keywords:                  
       Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
  Failure:  None/Unknown      |       Testcase:                  
Blockedby:                    |       Blocking:                  
  Related:                    |  
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 Would it be possible to make the 'let' keyword in a do block optional? So
 instead of

 {{{
 do ...
    let x = exp1
        y = exp2
    z <- exp3
    ...
 }}}

 you could simply write

 {{{
 do ...
    x = exp1
    y = exp2
    z <- exp3
    ...
 }}}

 Where each sequence of let-less bindings is put in a separate binding
 group. I'm no parsing wizard, but I couldn't come up with any situations
 in which this would cause ambiguity. To me, the let-less version is easier
 on the eyes, more consistent with <- bindings, and also makes it less of a
 hassle to move stuff around.

 The above probably also holds for list/monad comprehensions, but the
 explicit let has never really bothered me there.

 I've also posted the idea on Haskell cafe:
 [http://www.mail-archive.com/haskell-cafe@haskell.org/msg100541.html]

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7157>
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