Code to Joy

From Gogaruco 2012

Presenter: Avdi Grimm

These are a few of my favorite things

Remote pair programming with various developers
Thats so cool; I didn't know you could do that!

Ruby is designed to make programmers happy
Ruby makes me smile

Writing "Confident Ruby"
Can pay with a postcard which makes me happy

Random walk through Ruby and StdLib

Look at tools and idioms which make me happy

Splat

star or asterisk in Ruby Like having multiple return values

res = Struct.new(:code, :msg)
res.code
res.msg
code, msg = *r
# doesn't support implicit splating
res = Struct.new(:code, :msg) do
  # now it works!
  alias_method :to_ary, :to_a
end

Awesome magic!!!

yaml/store

Part of StdLid
File based persistence mechanism

require 'yaml/store'
# writes really clear yaml, objects are easily read
# really smart about objects referencing each other

require 'pstore'
# uses Ruby binary marshaling 

Good for maybe a command line app

Enumerators

What does this do?

Kernel.to_enum

Turns our method that yields into an iterable object

require 'pathname'
# Walk ancestor path of directory
Pathname.pwd.ascend do |dir|
  puts dir
end

curdir = Pathname.pwd
# give me iterable methods!
# all power of enumerable available to the series
configs = curdir.to_enum(:ascend)

Lets talk about break
We can stop a straightline method, and we can force an early exit

Ruby has my back; it cleans up after me

def foo
  yield 'baz'
  # does this second
  break
  yield 'doh'
ensure
  # does this first
  puts 'grimm'
end

You can pass a value to the break keyword
Breaks out of execution, but overrides methods return value

f = open 'file.txt'
result = f.lines.detect do |line| do
  # Give up after first 100 lines
  break "<Line Not Found>" if f.lineno >= 100
  line =~ /foo/
end
result # => "<Line Not Found>"

Subclassing Modules

Using Forwardable and def_delegators can potentially mean every change must be made twice

Maybe use SimpleDelegator, but we have to delegate twice and SimpleDelegator handles a single delegation

class Delegate < Module
  # When a message is sent to this object where this is included
  # It looks at itself
  # Than it looks at Delegate modules
  # ...and on up the ancestor chain
end

Create a new kind of module
Add state to the new module
Enables us to implement a new type of message delegation

MINASWAN

Matz is nice and so we are nice
To balance out technical debt or drama, write joyful code!
The only metric for joyful code is to share code
Give someone a wow moment (share code) to feel joyful!

NOTES

http://speakerrate.com/talks/16041
http://devblog.avdi.org/2012/06/05/confident-ruby-beta/
coupon: GOGARUCO2012 ...or send a postcard

QUESTIONS

Use define_method because its really hard to get at instance variables of module
By using a closure, you have access to the module attributes