Ruby » Ruby master

Feature #4787

Updated by nobu (Nobuyoshi Nakada) over 8 years ago

I suggest a new feature of Integer to enumerate by iterated Integer#modulo. 
 An example implementation in Ruby is the following code: 

 ```ruby 
 

   class Integer 
   
     def each_modulo(n) 
     
       raise ArgumentError, "argument must be an Integer" unless n.is_a? Integer 
     
       raise ArgumentError, "argument must be larger than 1" if n <= 1 
     
       return Enumerator.new(self, :each_modulo, n) unless block_given? 
     
       q = self 
     
       while q > 0 
       
         q, r = q.divmod(n) 
         yield(r) 
       yield(r) end 
     end 
   end 
 end 

 
  
   p 133.each_modulo(3).to_a #=> [1, 2, 2, 1, 1] 
 ``` 

 The following code is an example use of the feature: 

 ```ruby 
 

   class Integer 
   
     def each_thousand_separation 
       each_modulo(1000) 
     each_modulo(1000) 
   end 

   
  
     def thousand_separated_string(sep=',') 
     
       each_thousand_separation.map(&'%03d'.method(:%)).inject{|s, n| n + sep + s } 
     end 
   end 
 end 

 
  
   p 100_000_000_200.thousand_separated_string #=> "100,000,000,200" 
 ``` 

 I make an implementation in C, and attach the patch for that. 

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