Half Journey07 May 2015
Today is exactly the middle of my Batch at Recurce Center. Six weeks has passed and I just realized that I learned some stuff, but I have still much to learn here.
I just set for myself the objectives for the rest of the my Batch which will be to try to contribute to a OSS project while continuing to learn Clojure.
My plan is to post about what I learn (and my findings) but trying to avoid keeping too personal.
So what I learned today?
Resources for Closure
The list below is a must have favorites links for every person how would like to learn Clojure or plans to use it.
- Grimoire: A Cheatsheet of many Clojure functions presented in a nice way!
- ClojureDocs: Is the community-powered documentation and examples repository.
- Clojure Werkz A growing collection of open source Clojure libraries
What are they? What does it mean to have a Closure?
First, the definition by wikipedia:
In programming languages, closures (also lexical closures or function closures) are a technique for implementing lexically scoped name binding in languages with first-class functions. Operationally, a closure is a data structure storing a function together with an environment.
An example, implementing Power of function using Closures.
(defn pow [initial] (fn [x] (reduce * (repeat initial x))))
Calling the code above in the REPL:
user=> ((pow 2) 3) 9 user=> ((pow 6) 3) 729 user=> ((pow 3) 3) 27
So what just happened? We created a function which returns another function which happens to have an initial value stored on it’s instance in the memory.
I am not sure yet, but I can say that the initial variable, is now a “private attribute” of the instance of function pow which gets in the run time.
It seems a very powerful resource!