Dimitar Kostov mytrile

Rich Hickey on becoming a better developer

Rich Hickey • 3 years ago

Sorry, I have to disagree with the entire premise here.

A wide variety of experiences might lead to well-roundedness, but not to greatness, nor even goodness. By constantly switching from one thing to another you are always reaching above your comfort zone, yes, but doing so by resetting your skill and knowledge level to zero.

Mastery comes from a combination of at least several of the following:

Polymorphic Associations reversed

It's pretty easy to do polymorphic associations in Rails: A Picture can belong to either a BlogPost or an Article. But what if you need the relationship the other way around? A Picture, a Text and a Video can belong to an Article, and that article can find all media by calling @article.media

This example shows how to create an ArticleElement join model that handles the polymorphic relationship. To add fields that are common to all polymorphic models, add fields to the join model.

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

There is a bug in PhantomJS on Mac OS X that doesn't render an HTML page as selectable text. ~~It will be fixed in PhantomJS 2.0~~, so for now you'll have to apply a patch when installing with Homebrew.

First, update homebrew formulae:

$ brew update

If you already have PhantomJS installed, then remove it:

$ brew uninstall phantomjs Next, the PhantomJS formula needs to be edited to apply a patch that fixes native text rendering in Mac OS X:

	pool: number indicating size of connection pool (default 5)
	checkout_timeout: number of seconds to block and wait for a connection before giving up and raising a timeout error (default 5 seconds).
	reaping_frequency: frequency in seconds to periodically run the Reaper, which attempts to find and close dead connections, which can occur if a programmer forgets to close a connection at the end of a thread or a thread dies unexpectedly. (Default nil, which means don't run the Reaper).
	dead_connection_timeout: number of seconds from last checkout after which the Reaper will consider a connection reapable. (default 5 seconds).
	encoding: (Optional) Sets the client encoding by executing "SET NAMES <encoding>" after connection.
	reconnect: Defaults to false (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html).
	strict: Defaults to true. Enable STRICT_ALL_TABLES. (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en

	package demo

	import io.vertx.core.Vertx
	import io.vertx.core.http.HttpServer
	import io.vertx.core.http.HttpServerResponse
	import io.vertx.ext.web.Route
	import io.vertx.ext.web.Router
	import io.vertx.ext.web.RoutingContext

	fun Router.get(path: String, handler: (RoutingContext) -> Unit): Route {

	FROM elixir:1.2.3
	MAINTAINER Sergey Gernyak <[email protected]>

	ENV MIX_ENV=prod

	RUN apt-get update && apt-get install -y build-essential git-core

	RUN mkdir -p /app

	WORKDIR /app

	#!/bin/sh
	#

	if [ "X$SSH_AUTH_SOCK" = "X" ]; then
	eval `ssh-agent -s`
	ssh-add $HOME/.ssh/id_rsa
	fi

	HOST=
	REDIS_SLAVE_PORT=6000

	defmodule RestClient do
	require Logger
	alias Poison, as: JSON

	@baseurl "http://someapi.com"
	@username "username"
	@password "password"

	def get_by_path(path, id, params)
	when is_binary(id) or is_integer(id) and is_list(params) do

	def currency_euro(item)
	number_to_currency(item, :unit => "€", :separator => ",", :delimiter => "", :format => "%n %u")
	end