[ruby-dev:49646] [Ruby trunk Feature#4787] Integer#each_modulo(n)

[nobu@ruby-lang.org]

Issue #4787 has been updated by Nobuyoshi Nakada.

Description updated

----------------------------------------
Feature #4787: Integer#each_modulo(n)
https://bugs.ruby-lang.org/issues/4787#change-59040

* Author: Kenta Murata
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
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)
    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)
  end

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


---Files--------------------------------
each_modulo.patch (3.91 KB)


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