[Haskell] Re: [Haskell-cafe] ANN: cmonad 0.1.1

Claus Reinke claus.reinke at talk21.com
Mon Mar 30 04:34:16 EDT 2009

| When I looked at it a year ago or so, it was a return of one
| constructor in a sum.
| Looking at core, you can see several places where a function is called
| and that function always returns the same constructor, so the case
| analysis of the return value is not needed; it should be returned as
| an unboxed tuple instead
| I'll see if I can get a simple example to illustrate the problem.

>That would be very helpful, thanks.  Having a Trac ticket with 
>a small reproducible test case, and a pointer to a larger example 
>that illustrates its importance, would be great.  Indeed, it is pervasive, 
>or can you try the effect of performing the transformation by hand, 
>and seeing if it makes a difference?

>That doesn't guarantee that I, or anyone else, will get to it, but 
>it makes it much much more likely!

And in the meantime, it documents a possible performance trap
for others who might not be able to track down the cause, or
even notice that they are shooting themselves in the foot.


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