[stack] Fwd: MapReduce as a Cat one-liner

I thought members of the Cat discussion group and the concatenative
mailing list would be interested in the Cat implementation of the
Google MapReduce algorithm, so I forwarded an email from the Seattle
Functional Users Group mailing list.

---------- Forwarded message ----------
From: Christopher Diggins <[email protected]>
Date: Apr 3, 2007 12:43 PM
Subject: MapReduce as a Cat one-liner
To: [email protected]


Frank Krueger ( http://www.praeclarum.org/ ) a fellow member of the
Seattle functional users group, asked me to come up with a simple
implementation of the Google MapReduce algorithm in Cat, to compare to
the C# implementation on his blog. Here is what I came up with:

  define map_reduce { [map flatten self_join] dip map }

I've explained this algorithm in more depth on the Cat wiki (
http://code.google.com/p/cat-language/wiki/MapReduce ).

Of course I should at least tell you that the type is:

 map_reduce : (list ('a -> 'b) ('c -> 'd) -> list)

Unfortunately the Cat type system isn't yet sophisticated enough to
express the structure of lists, which would be key to making the type
more descriptive.

I'll be attending the East-side SeaFunc meeting early tommorrow (at
around 7pm) at the Overlake Red Robin (at the corner of 148th and
24th) if you care to show up earlier than usual.

Cheers,
Christopher Diggins


-- 
http://www.cdiggins.com