[vector] #51: optimization of fst . unzip . zip

[vector]

#51: optimization of fst . unzip . zip
-----------------------------------+----------------------------------------
Reporter:  choener                 |        Owner:     
    Type:  enhancement             |       Status:  new
Priority:  minor                   |    Milestone:  0.8
 Version:  0.7                     |   Resolution:     
Keywords:  code-path optimization  |  
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Changes (by rl):

  * milestone:  => 0.8


Comment:

 We have some support for this in DPH but I haven't included it in vector
 yet. Note that for fusion to work, you would have to write this:

 {{{
 g = map fst
 }}}

 rather than this:

 {{{
 g = fst . unzip
 }}}

 The latter is impossible to match on. For the former, we're just missing a
 couple of rules, I'll add them in the next release.

-- 
Ticket URL: <http://trac.haskell.org/vector/ticket/51#comment:1>
vector <http://trac.haskell.org/vector>
Package vector