[GHC] #15263: Fuse zipWith3

[GHC]

#15263: Fuse zipWith3
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by mpickering):

 If you are going to do that, you might as well define `zipWith3` in that
 way to begin with?

 In fact, defining `zipWith3` in this way and adding an `INLINE` pragma
 causes it to fuse nicely with map.

 My example program and the resulting core here -
 https://gist.github.com/mpickering/c190fc25260a3460f4633d0248659192

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15263#comment:1>
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