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Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Channel#receive vs Channel#receive? differs on their behavior for closed channels. Using them directly is always blocking.

Performing an operation over a closed and closing the channel during the operation must behave in the same way.

Use the -d flag with run command.

EG:

eval $(docker-machine env feature)
docker-compose -f delivery.docker-compose.yml run -d rails rake db:seed

start new:

tmux

start new with session name:

tmux new -s myname

(C-x means ctrl+x, M-x means alt+x)

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

	// haversin(θ) function
	func hsin(theta float64) float64 {
	return math.Pow(math.Sin(theta/2), 2)
	}

	// Distance function returns the distance (in meters) between two points of
	// a given longitude and latitude relatively accurately (using a spherical
	// approximation of the Earth) through the Haversin Distance Formula for
	// great arc distance on a sphere with accuracy for small distances
	//

	type (
	// BuoyCondition contains information for an individual station.
	BuoyCondition struct {
	WindSpeed float64 `bson:"wind_speed_milehour"`
	WindDirection int `bson:"wind_direction_degnorth"`
	WindGust float64 `bson:"gust_wind_speed_milehour"`
	}

	// BuoyLocation contains the buoy's location.
	BuoyLocation struct {

	/* Exercise: Loops and Functions #43 */
	package main

	import (
	"fmt"
	"math"
	)

	func Sqrt(x float64) float64 {
	z := float64(2.)

	# Jekyll archive page generator with pagination.
	#
	# Based on the category generator from
	# http://recursive-design.com/projects/jekyll-plugins/,
	# which is copyright (c) 2010 Dave Perrett,
	# http://recursive-design.com/ and is licensed under the MIT
	# license (http://www.opensource.org/licenses/mit-license.php), and
	# on the pagination code from Jekyll itself.
	#
	# This code is copyright (c) 2011 Benjamin Curtis, and is licensed