# Uses the array as arguments for the object's send method

class Array
  def to_proc
    Proc.new{ |obj|
      obj.send *self
    }
  end
end

# usage
#  [1,2,3,4,5].map &[:to_s, 2]  # => ["1", "10", "11", "100", "101"]

# If the object is found as key in the hash, this runs its value as proc,
#  else it just returns the object.

class Hash
  def to_proc
    Proc.new{ |obj|
      if self.member? obj
        self[obj].to_proc.call obj
      else
        obj
      end
    }
  end
end

# usage
#  [1,2,3,4,5].map &{ 1 => :to_s,
#                     3 => [:to_s, 2] } # if you use Array#to_proc
#  => ["1", 2, "11", 4, 5]

# Use this with string arrays

class Regexp
  def to_proc
    Proc.new{ |e|
      e.to_s[self]
    }
  end
end

# usage
#  %w|just another string array|.map    &/[jy]/  # => ["j", nil, nil, "y"]
#  %w|just another string array|.select &/[jy]/  # => ["just", "array"]

# Shortcut for initializing objects

class Class
  def to_proc
    Proc.new{ |*args|
      self.new *args
    }
  end
end

# usage
#  [[1,2],[3,5,6,7]].map &Set  # => [#<Set: {1, 2}>, #<Set: {5, 6, 7, 3}>]