Rubybits2 LEVEL 1: Proc, block, lambda

gistfile1.rb

# & then proc object into block
# & also could then block into a proc object
# & 可以讓proc object 跟 block 切來切去

# Calling a method with & in front of a parameter
tweets.each(&printer)  # turns a proc into block

# Defining a method with & in front of a parameter
def each(&block) # turns a block into a proc, so it can be assigned to parameter

timeline = Timeline.new(tweets)
  timeline.each do |tweet| puts tweet
end

class Timeline
  attr_accessor :tweets
  def each
    tweets.each { |tweet| yield tweet }
  end 
end


class Timeline
  attr_accessor :tweets
  def each(&block)      # turn block to proc object
    tweets.each(&block) # turn proc object to block
  end
end