refactor.rb

# How I might do it 3 months ago in a different language
n = 0
item.categories.each do |category|  
  puts category.title
  break if n == item.categories.count
  puts ", "
  n += 1
end

# How I tried it first in ruby
names = item.categories.collect {|category| category.title}
puts names.join(", ")

# Oh, I can method-chain that?
puts item.categories.collect {|category| category.title}.join(", ")

# Then, Ryan Waldron (@erebor) swoops in and blows my mind
puts item.categories.collect(&:title).join(", ")

# Mind blown
# Symbol#to_proc
# http://pragdave.pragprog.com/pragdave/2005/11/symbolto_proc.html