Hi all, I've just released an early version of 'Yo-yo', a protocol-less, function composition-based alternative to Component. It's still in its early stages, so feedback would be very much appreciated!
https://github.com/james-henderson/yoyo Yo-yo was also an experiment to see what could be de-coupled from the concept of 'reloadable systems', so you won't find any configuration, dependency injection, etc - just a way to write a system that can be easily started, stopped, and reloaded. Fundamentally, we start by assuming there's a function available that only returns 'when the system stops' - a 'latch', say. If we had such a function, we could start our system, call that function, then stop the system (closing any necessary resources). A database pool, for example, might look like this: (defn with-db-pool [db-config f] (let [db-pool (start-pool! db-config)] (try (f db-pool) (finally (stop-pool! db-pool))))) Here, we're assuming that we'll be passed 'f', the 'latch' function. A web server would be similar, and, because they're both functions, they're very simple to compose: (with-db-pool {...} (fn [db-pool] (with-web-server {:handler (make-handler {:db-pool db-pool}) :port ...} (fn [web-server] ;; TODO: Ah. We've run out of turtles. :( )))) This is where Yo-yo comes in - there’s a function called run-system!, which takes a function that accepts a latch: (:require [yoyo]) (yoyo/run-system! (fn [latch] (with-db-pool {...} (fn [db-pool] (with-web-server {:handler (make-handler {:db-pool db-pool}) ; n.b. we have access to the db-pool here - no need for global state! :port ...} (fn [web-server] (latch))))))) ; Aha! run-system! then returns a promise - deliver any value to it, and it'll stop the system. And that's pretty much it! There are a few more functions - mostly to do with easily starting/stopping/reloading a system through the REPL, and a macro to simplify the 'function staircase' - these are covered in more detail in the README. There are some also common components - a database pool, a web server, and a simple integration for existing Component systems. It'd be great to hear your thoughts/ideas, whatever they may be - either through here, e-mail, Github, or Twitter - thanks! James -- 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.
