Re: [Haskell-cafe] Why monoids will abide...

2009-01-23 Thread Brandon S. Allbery KF8NH
On 2009 Jan 22, at 10:09, Andrew Wagner wrote: See, that's the kind of name we need! StructureWithAssociativeOperationAndIdentity -- make both the mathematicians AND the non-mathematicians mad! "SimpleArithmetic" (you have "numbers" and a single "arithmetic operation" on them). You can pl

Re: [Haskell-cafe] Why monoids will abide...

2009-01-22 Thread Tim Newsham
On Thu, 22 Jan 2009, Eugene Kirpichov wrote: To my mind, in the map-reduce case you generally need a commutative monoid. Or, you need an extra infrastructure that mappend's only results from adjacent machines, or something like that. The paper http://www.cs.vu.nl/~ralf/MapReduce/ analyzes t

Re: [Haskell-cafe] Why monoids will abide...

2009-01-22 Thread Eugene Kirpichov
Thanks; I saw you mention the paper before, but now I finally started reading it :) By the way, the paper *does* arrange an extra infrastructure for mappending only adjacent results. Looks like with a commutative monoid, a fold could be done in a fully distributed fashion, however it would no more

Re: [Haskell-cafe] Why monoids will abide...

2009-01-22 Thread Ross Paterson
On Thu, Jan 22, 2009 at 06:53:24AM -0800, Dan Piponi wrote: > On Wed, Jan 21, 2009 at 11:12 PM, Eugene Kirpichov > wrote: > > To my mind, in the map-reduce case you generally need a commutative > > monoid. Or, you need an extra infrastructure that mappend's only > > results from adjacent machines

Re: [Haskell-cafe] Why monoids will abide...

2009-01-22 Thread Andrew Wagner
See, that's the kind of name we need! StructureWithAssociativeOperationAndIdentity -- make both the mathematicians AND the non-mathematicians mad! On Thu, Jan 22, 2009 at 9:53 AM, Dan Piponi wrote: > On Wed, Jan 21, 2009 at 11:12 PM, Eugene Kirpichov > wrote: > > To my mind, in the map-reduce c

Re: [Haskell-cafe] Why monoids will abide...

2009-01-22 Thread Dan Piponi
On Wed, Jan 21, 2009 at 11:12 PM, Eugene Kirpichov wrote: > To my mind, in the map-reduce case you generally need a commutative > monoid. Or, you need an extra infrastructure that mappend's only > results from adjacent machines, or something like that. This is a good paper on the stuff I'm talkin

Re: [Haskell-cafe] Why monoids will abide...

2009-01-21 Thread Eugene Kirpichov
To my mind, in the map-reduce case you generally need a commutative monoid. Or, you need an extra infrastructure that mappend's only results from adjacent machines, or something like that. 2009/1/21 Dan Piponi : > Another important application of monoids is in parallelisation. In > map-reduce you

Re: [Haskell-cafe] Why monoids will abide...

2009-01-21 Thread Dan Piponi
Another important application of monoids is in parallelisation. In map-reduce you want to split the reduce part over multiple processors and combine the results back together again. Associativity ensures that when you combine the pieces together you get the same result as if you did the whole opera

Re: [Haskell-cafe] Why monoids will abide...

2009-01-20 Thread minh thu
2009/1/21 Don Stewart : > http://apfelmus.nfshost.com/monoid-fingertree.html > > Thanks Apfelmus for this inspiring contribution! > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > And fo

[Haskell-cafe] Why monoids will abide...

2009-01-20 Thread Don Stewart
http://apfelmus.nfshost.com/monoid-fingertree.html Thanks Apfelmus for this inspiring contribution! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe