Common Ruby Idioms

Question

One thing I love about ruby is that mostly it is a very readable language (which is great for self-documenting code)

However, inspired by this question: Ruby Code ex

Answer 1

Some more idioms:

Use of the %w, %r and %( delimiters

%w{ An array of strings %}
%r{ ^http:// }
%{ I don't care if the string has 'single' or "double" strings }

Type comparison in case statements

def something(x)
  case x
    when Array
      # Do something with array
    when String
      # Do something with string
    else
      # You should really teach your objects how to 'quack', don't you?
  end
end

... and overall abuse of the === method in case statements

case x
  when 'something concrete' then ...
  when SomeClass then ...
  when /matches this/ then ...
  when (10...20) then ...
  when some_condition >= some_value then ...
  else ...
end

Something that should look natural to Rubyists, but maybe not so to people coming from other languages: the use of each in favor of for .. in

some_iterable_object.each{|item| ... }

In Ruby 1.9+, Rails, or by patching the Symbol#to_proc method, this is becoming an increasingly popular idiom:

strings.map(&:upcase)

Conditional method/constant definition

SOME_CONSTANT = "value" unless defined?(SOME_CONSTANT)

Query methods and destructive (bang) methods

def is_awesome?
  # Return some state of the object, usually a boolean
end

def make_awesome!
  # Modify the state of the object
end

Implicit splat parameters

[[1, 2], [3, 4], [5, 6]].each{ |first, second| puts "(#{first}, #{second})" }