Transducers are *reducing function transformers*. They take a reducing function and return another reducing function with some new actions. E.g.
(let [xf ((comp (map inc) (filter even?)))] (reduce (xf +) 0 [1 2 3])) Here, `xf` is the transducer. It takes the reducing function `+` as an argument and returns another reducing function that incorporates the `(map inc)` and the `(filter even?)` into the `+`. There are some fine details about order of composition, but that's the gist of it. What transducers do is capture the entire logic of *what* to do, while the collection (*reducible*) handles *how* to do it (by implementing one of the reduce-related interfaces, e.g. `CollReduce`). This is a useful decomplection of concerns. Coincidentally, I was just preparing a presentation on reducers/transducers, so here's a big 'ol list of references on transducers: - Transducers are Coming <http://blog.cognitect.com/blog/2014/8/6/transducers-are-coming> - Transducers (Video) <https://www.youtube.com/watch?v=6mTbuzafcII> - Inside Transducers (Video) <https://www.youtube.com/watch?v=4KqUvG8HPYo> - Rich Hickey explaining transducers--in Haskell <https://www.reddit.com/r/haskell/comments/2cv6l4/clojures_transducers_are_perverse_lenses/cjjyay7/> - Building ETL pipelines with Clojure and transducers <https://tech.grammarly.com/blog/building-etl-pipelines-with-clojure> On Friday, May 12, 2017 at 5:47:19 PM UTC-7, tbc++ wrote: > > Sure, you can contact me at the address used in this reply :) > > Timothy Baldridge > > On Fri, May 12, 2017 at 11:19 AM, Erlis Vidal <er...@erlisvidal.com > <javascript:>> wrote: > >> Is there a way I can contact Tim Baldridge for questions about the >> subscription? >> >> Thanks! >> >> On Sun, Jan 31, 2016 at 12:40 PM, Mars0i <mars...@logical.net >> <javascript:>> wrote: >> >>> Thanks jjttjj, Magomimmo. I do prefer reading to videos, but I'll >>> consider getting Baldridge's series anyway. Seems worth it. I don't mind >>> paying. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Clojure" group. >>> To post to this group, send email to clo...@googlegroups.com >>> <javascript:> >>> Note that posts from new members are moderated - please be patient with >>> your first post. >>> To unsubscribe from this group, send email to >>> clojure+u...@googlegroups.com <javascript:> >>> For more options, visit this group at >>> http://groups.google.com/group/clojure?hl=en >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "Clojure" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to clojure+u...@googlegroups.com <javascript:>. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com >> <javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/clojure?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "Clojure" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > “One of the main causes of the fall of the Roman Empire was that–lacking > zero–they had no way to indicate successful termination of their C > programs.” > (Robert Firth) > -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
