Ah, contains?… supposedly one of the top five FAQs re: Clojure. It does not check whether a collection contains a value; it checks whether an item could be retrieved with get or, in other words, whether a collection contains a key. This makes sense for sets (which can be thought of as making no distinction … Read more
Or (use ‘your.namespace :reload)
Thank God that the software-engineering people have not yet discovered functional programming. Here are some parallels: Many OO “design patterns” are captured as higher-order functions. For example, the Visitor pattern is known in the functional world as a “fold” (or if you are a pointy-headed theorist, a “catamorphism”). In functional languages, data types are mostly … Read more
Compojure is no longer a complete framework for developing web applications. Since the 0.4 release, compojure has been broken off into several projects. Ring provides the foundation by abstracting away the HTTP request and response process. Ring will parse the incoming request and generate a map containing all of the parts of the request such … Read more
There’s also dotrace, which allows you to look at the inputs and outputs of selected functions. (use ‘clojure.contrib.trace) (defn fib[n] (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2))))) (dotrace [fib] (fib 3)) produces the output: TRACE t4425: (fib 3) TRACE t4426: | (fib 2) TRACE t4427: | | (fib … Read more
If the repl is still running from the previous cider-jack-in, you should either use the cidercommand to connect to the running instance, or stop the previous before starting a new one From Here `Clojure – connection issue re-running cider-jack-in Also see this https://devcenter.heroku.com/articles/debugging-clojure
Groovy is a dynamically typed language, whose syntax is very close to Java, with a number of syntax improvements that allow for lighter code and less boilerplate. It can run through an interpreter as well as being compiled, which makes it good for fast prototyping, scripts, and learning dynamic languages without having to learn a … Read more