I'm happy to have pushed [1] today the beginnings of a new Clojure library for higher-order manipulation of collections, based upon *reduce* and *fold*. Of course, Clojure already has Lisp's *reduce*, which corresponds to the traditional *foldl* of functional programming. *reduce* is based upon sequences, as are many of the core functions of Clojure, like *map*, *filter* etc. So, what could be better? It's a long story, so I'll give you the ending first:
* There is a new namespace: clojure.core.reducers * It contains new versions of *map*, *filter* etc based upon transforming reducing functions - reducers * It contains a new function, **fold**, which is a parallel reduce+combine * *fold* uses **fork/join** when working with (the existing!) Clojure vectors and maps * Your new parallel code has exactly the same shape as your existing seq-based code * The reducers are composable * Reducer implementations are primarily functional - no iterators * The model uses regular data structures, not 'parallel collections' or other OO malarkey * It's fast, and can become faster still * This is work-in-progress I've described the library in more detail here: http://clojure.com/blog/2012/05/08/reducers-a-library-and-model-for-collection-processing.html Rich [1] https://github.com/clojure/clojure/commit/89e5dce0fdfec4bc09fa956512af08d8b14004f6 -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
