gistfile1.txt

== overview:

builtin: rake, rubygems, json, securerandom, HMAC digests
removed: base64 (unpack("m*"))

== nye ting:

Hash syntax ( {foo: "bar"} #=> {:foo => "bar"})

proc/lamnda syntax: 
  p = ->(n){ n + 1 }; p.(42) #=> 43
  
  >> greeter = ->person{ "Hello there, #{person}!" }
  => #<Proc:0x3f7578@(irb):51 (lambda)>
  >> greeter.call("Marius")
  => "Hello there, Marius!"
  >> greeter.yield "Marius"
  => "Hello there, Marius!"
  

Flere Hash Enumerable operasjoner returnerer en hash (#select etc)

Hash ordered by insertion

Object#tap:
>> foo_with_thing = Foo.new.tap do |fooer|
?>     fooer.bar = "it's where you get drinks"
>>   end
=> #<Foo:0x3f5e30 @bar="it's where you get drinks">

(Object#returning i Rails/ActiveSupport)

Symboler mere som strenger:
:foo =~ /oo$/

String#[]:
1.8:
  >> "foo"[0]
  => 102
1.9:
  >> "foo"[0]
  => "f"
  >> "foo"[0].ord
  => 102
  
String er ikke Enumerable:
>> "ruby".each
NoMethodError: undefined method `each' for "ruby":String
	from (irb):38
	from /usr/local/bin/irb1.9:12:in `<main>'
>> "ruby".each_char{|c| p c }
"r"
"u"
"b"
"y"

#each => #each_line
>> "ru\nby".each_line{|line| p line }
"ru\n"
"by"

Array/Hash#to_s == #inspect
>> [1,2,3].to_s
=> "[1, 2, 3]"
>> {:foo => 1, :bar => 2}.to_s
=> "{:foo=>1, :bar=>2}"


== OS Threads


== methods: 

>> def foo(bar = 1, baz) p [bar, baz] end
>> foo("wtf") 
[1, "wtf"]

>> def foo(a, *b, c) p [a,b,c] end
=> nil
>> foo(1, 2,3,4, 5)
[1, [2, 3, 4], 5]

== Oniguruma

Named captures:
>> md = "hello ruby world".match(/^hello (?<what>.+) world$/)
=> #<MatchData "hello ruby world" what:"ruby">
>> md.captures
=> ["ruby"]
>> md.names
=> ["what"]
>> md[:what]
=> "ruby"


== local/blocklocal variables:

>> i = :foo
>> [1,2,3].each{|i| p i}
1
2
3
=> [1, 2, 3]
>> i
=> :foo

== Enumerable

>> enum = %w[a b c d].map
=> #<Enumerator:0x432b14>


>> enum.with_index{|letter, index| puts "#{letter} is #{index}" }
a is 0
b is 1
c is 2
d is 3

>> [1,2,3,4].count{|i| i > 3 }
=> 1

>> arr.take(2)
=> [1, 2]
>> arr
=> [1, 2, 3, 4, 5]
>> arr.group_by{|i| i % 2 }
=> {1=>[1, 3, 5], 0=>[2, 4]}

>> enum = [1,2,3,4].to_enum
=> #<Enumerator:0x406140>
>> loop{ n = enum.next; p n }
1
2
3
4

>> [].to_enum.next
raises: StopIteration: iteration reached at end
>> loop{ raise StopIteration }
=> nil





== BasicObject

>> BasicObject.ancestors
=> [BasicObject]
>> Object.ancestors
=> [Object, PP::ObjectMixin, Kernel, BasicObject]


== m17n

* encodings
* string encodings (converting, multibyte #size etc)
* file encodings (åpne med angitt encoding) (File.open("foo.txt", "r:utf-8"))

>> "åke".size
=> 3

>> "abc".bytes
=> #<Enumerator:0x1eddf4>
>> "abc".bytes.each {|byte| p byte }
97
98
99


* "Magic comment":
  # encoding: utf-8
  
  >> π = Math::PI
  >> p π 
  => 3.14159265358979


== Rails

it works!


=== Marius føyer til…


==== Fibers (in progress)

  f = Fiber.new do
    a,b = 0,1
    Fiber.yield a
    Fiber.yield b
    loop do
      a,b = b,a+b
      Fiber.yield b
    end
  end
  10.times {puts f.resume}

==== When not valid in when statements:

  case "me"
    when String:
      # raises
  end

==== Method#to_proc

  %w(john jane).collect(&:capitalize)

==== Nested methods

  def visited
    def visited
      "been there, done that"
    end
    "first timer"
  end
    
==== $"

Like $:


==== Integer niceties

  1.odd?
  2.even?

==== Method niceties

  class A
    def foo
    end
  end
  
  a = A.new
  a.method(:foo).receiver   #=> The instance
  a.method(:foo).owner      #=> The class

Som betyr at du for eksempel kan finne ut om en metode kommer fra klasse eller mix-in

  module Fooable
    def foo
    end
  end
  
  class Foo
    include Fooable
  end
  
  f = Foo.new
  f.method(:foo).owner    #-> Fooable

==== Object#type gone forever

  RUBY_VERSION    #=> 1.9.1
  "Ruby".type     #=> NoMethodError: undefined method `type' for "Ruby":String