Program Development - quotes

• In order to understand recursion, one must first understand recursion
• Any fool can write code that a computer can understand. Good programmers write code that humans can understand - Martin Fowler
• Programming is about learning something new every day -Simone Carletti
• Code never lies, comments do. - Alexander Dvorkovyy
• Always code as if the person who ends up maintaining your code is a violent psychopath who knows where you live - Rick Osborne or John Woo
• Don't worry about the wasted effort unless you know - by measurement - that the waste is noticeable and important. Always favor the clean code you need over than the fast code you might need. - Brian Marick
• So why was it so hard to tell a computer to do something only mildly complex? Well, it wasn't the "mildly complex" part that was giving me problems; it was the "tell a computer" part. - Chris Pine
• Java is to JavaScript what Car is to Carpet - Chris Heilmann
• A good programmer is someone who looks both ways before crossing a one-way street - ?
• Programming isn't about what you know; it's about what you can figure out. As long as you know where to find out the things you forgot, your doing just fine - Chris Pine
• Debugging is like farting - it's not so bad when it's your own code - Paul Downey
• I don't care if it works on your machine! We are not shipping your machine! - Ovidiu Platon
• You wanted a banana but what you got was a gorilla holding the banana and the entire jungle - Joe Armstrong
• Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away - Antoine de Saint Exupéry
• When I am working on a problem I never think about beauty. I only think about how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong - Buckminster Fuller
• There are only two hard problems in Computer Science: cache invalidation and naming things - Phil Karlton
• There is No code that is more flexible than no code - Brad Appleton
• I get paid for code that works, not for tests, so my philosophy is to test as little as possible to reach a given level of confidence - Kent Beck
• If you try to please everyone, you won't please anyone - 37signals
• When you're explaining something to somebody and they don't get it, that's not their problem, it's your problem - Jeff Atwood
• Fail to plan is plan to fail - Benjamin Franklin
• Simplicity is the ultimate sophistication - Leonardo Da Vinci
• If you can’t measure something, you can’t understand it. If you can’t understand it, you can’t control it. If you can’t control it, you can’t improve it - H. James Harrington
• Just because something is easy to measure, it doesn't mean it's important - Seth Godin
• The First Rule of Program Optimization: Don't do it. The Second Rule of Program Optimization (for experts only!): Don't do it yet. — Michael A. Jackson

Rails 4.1 diagram

Html status diagram

regex to update from rspec 1 to rspec 2

Rspec 2 removes assign_to and replace it with assigns, here are the regex I'm using in sublime text 2 for the update:

should assign_to\((.*)\).with\(nil\)
assigns($1).should be_nil

should assign_to\(:(.+)\).with\((.+)\)
assigns(:$1).should == $2

should_not assign_to\(:(.*)\)
assigns(:$1).should be_nil

should assign_to\(:(.*)\)
assigns(:$1).should_not be_nil

Links to some doc here

quick upload to amazon S3 with Fog and Carrierwave

require 'rubygems'
require 'fog' # version 1.10.1


fog_credentials = {
  provider: "AWS",
  aws_access_key_id: "QWERTTYQWERTTYQWERTT",
  aws_secret_access_key: "q1w2e3r4t5yQWERTYUq1w2e3r4t5yQWERTYasdf1",
  region: "ap-southeast-2" # Sydney ;)
}


CONNECTION = Fog::Storage.new fog_credentials

S3 = CONNECTION.directories.get 'bucket-name'
S3.files.create(key: 'test_me/test1', body: 'xxxxxxxxx')

The following works with Carrierwave

require 'carrierwave'
require 'fog'

CarrierWave.configure do |config|
  config.fog_credentials = {
    provider:              'AWS',
    aws_access_key_id:     'QWERTYQWERTYQWERTYTY',
    aws_secret_access_key: 'qewr1234qewr1234qwer1234qwer1234qwer1234',
    region:                'ap-southeast-2' # Sydney :)
  }
  config.fog_public    = false
  config.fog_directory = 'bucket-name'
end

class MyUploader < CarrierWave::Uploader::Base
  storage :fog
end

file = File.open('/tmp/tmp.txt')
uploader = MyUploader.new
uploader.store!(file)

ruby operator precedence explained with an example

OR has lower precence than ||, in particular assignments (=) are in the middle, therefor:

a = false || true # => true
a                 # => **true**  => a = (false || true)
# BUT
a = false or true # => true
a                 # => **false** => (a = false) or true

# another BIG difference
:a || :b && :c  # => :a          => (:a || :b) && :c
# BUT 
:a or :b and :c # => **c**       => :a or (:b and :c)

Got it?
Where does it make sense to use the English operators?

a = value or raise "a cannot be nil"

def tail_color(args)
  animal = args[:animal] and
  tail = animal.tail and
  tail.color
end

Conclusion: only use English operators for flow control, not in if statements
also see this table

Ruby, Rails and Etc conventions

• ruby
• rails (includes rspec)
• rails code struture in models consistent
• my gist for conventions