Yiorgos Michokostas gmichokostas

My issues with Modules

In researching topics for RailsCasts I often read code in Rails and other gems. This is a great exercise to do. Not only will you pick up some coding tips, but it can help you better understand what makes code readable.

A common practice to organize code in gems is to divide it into modules. When this is done extensively I find it becomes very difficult to read. Before I explain further, a quick detour on instance_eval.

You can find instance_eval used in many DSLs: from routes to state machines. Here's an example from Thinking Sphinx.

class Article &lt; ActiveRecord::Base

Hofstadter on Lisp

In the mid-80s, while reading through my roommate's collection of Scientific American back issues, I encountered this introduction to Lisp written by Douglas Hofstadter. I found it very charming at the time, and provide it here (somewhat illegally) for the edification of a new generation of Lispers.

In a testament to the timelessness of Lisp, you can still run all the examples below in emacs if you install these aliases:

(defalias 'plus #'+)
(defalias 'quotient #'/)
(defalias 'times #'*)
(defalias 'difference #'-)

#!/bin/ruby --verion => 2.0.0-p353

Self

In Ruby, self is a special variable that always references the current object.

Inside class or module definition, self refer to the Class or Module object.
Inside instance method, self refer to future instance object.
Inside class method, self refer to the class.i

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors and Sequences

UPDATE a fork of this gist has been used as a starting point for a community-maintained "awesome" list: machine-learning-with-ruby Please look here for the most up-to-date info!

Resources for Machine Learning in Ruby

Gems

liblinear-ruby: Ruby interface to LIBLINEAR using SWIG

	;; The Computer Language Benchmarks Game
	;; http://shootout.alioth.debian.org/
	;
	;; Adapted from the Java -server version
	;
	;; contributed by Marko Kocic
	;; modified by Kenneth Jonsson, restructured to allow usage of 'pmap'
	;; modified by Andy Fingerhut to use faster primitive math ops, and
	;; deftype instead of defrecord for smaller tree nodes.
	;; https://github.com/jafingerhut/clojure-benchmarks/blob/master/binarytrees/binarytrees.clj-4.clj modified by RH for 1.3

	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Ant sim ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	; Copyright (c) Rich Hickey. All rights reserved.
	; The use and distribution terms for this software are covered by the
	; Common Public License 1.0 (http://opensource.org/licenses/cpl.php)
	; which can be found in the file CPL.TXT at the root of this distribution.
	; By using this software in any fashion, you are agreeing to be bound by
	; the terms of this license.
	; You must not remove this notice, or any other, from this software.

	;dimensions of square world

	-module(generic_proxy).

	-export([run/0]).

	-define(PORT_FROM, 63790).
	-define(PORT_TO, 6379).
	-define(BACKLOG, 10000).

	run() ->
	{ok, Socket} = gen_tcp:listen(0, [

	(require '[clojure.core.async :as a])

	(def xform (comp (map inc)
	(filter even?)
	(dedupe)
	(flatmap range)
	(partition-all 3)
	(partition-by #(< (apply + %) 7))
	(flatmap flatten)
	(random-sample 1.0)