FizzBuzzクラス

fizzbuzz.rb

class FizzBuzz
  
  def initialize( from = 1, to = 30 )
    @from, @to = [ from, to ].minmax
    block_given? ? yield( self ) : self
  end
  
  def spec( out, &cond )
    ( @specs ||= [] ) << lambda { |e| cond[ e ] ? out : nil }
  end
    
  def edit( &editor )
    @editor  = editor
  end
  
  def editor
    @editor || lambda { |e| e }
  end

  def format( &formatter )
    @formatter = formatter
  end
  
  def output( &formatter )
    @formatter = formatter if formatter
    result = @from.upto( @to ).map( &self )
    @formatter ?  result.map { |e| @formatter[ e ] } : result
  end

  def to_proc
    lambda { |i| 
      outs = @specs.map { |spec| spec[ i ] }
      editor[ i, outs ]
    }
  end  

end

main_fizzbuzz.rb

require "./fizzbuzz"

# Pattern 1 : (1..30)
FizzBuzz.new do |fizzbuzz|

  fizzbuzz.spec( :Fizz ) { |e| e % 3 == 0 }
  fizzbuzz.spec( :Buzz ) { |e| e % 5 == 0 }

  fizzbuzz.edit { |i, outs| 
    out = outs.join
    out.empty? ? i : out
  }
  
end.output do |e|
  puts e
end

# Pattern 2 : (31..69)
fizzbuzz = FizzBuzz.new(31, 69)
fizzbuzz.edit { |i, outs| 
  out = outs.join
  out.empty? ? i : out
}
fizzbuzz.spec( :B ) { |e| e % 5 == 0 }
fizzbuzz.spec( :F ) { |e| e % 3 == 0 }
result = fizzbuzz.output
puts result * " "

# Pattern 3 : (70..105)
FizzBuzz.new(70, 105) do |fizzbuzz|

  fizzbuzz.spec( :Pizz ) { |e| e % 3 == 0 }
  fizzbuzz.spec( :Quzz ) { |e| e % 5 == 0 }
  fizzbuzz.spec( :Razz ) { |e| e % 7 == 0 }

  fizzbuzz.edit { |i, outs| 
    out = outs.join
    out.empty? ? i : out
  }
  
  fizzbuzz.format { |e| puts e }
  
end.output