Pattern Matching DSL

pattern.rb

# Pattern matching DSL ideas

class Object
  def method_missing method_name, *args, &block
    if method_name.to_s == "_"
      :default
    else
      super
    end
  end
end

module PatternMatch
  def self.match x, &block
    h = block.call()
    match = h[x]
    match.nil? ? h[:default] : match
  end
end

def matcher n
  result = PatternMatch::match n do {
    10 => "It is 10",
    20 => "It is 20",
    _  => "No match" }
  end
end

puts matcher(10)
puts matcher(200)