From: Robert Dober <robert.dober@...>
Date: 2007-06-09T05:07:27+09:00
Subject: Re: What about a 'series' type?

On 6/8/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> On 08.06.2007 14:27, Robert Dober wrote:
> > On 6/8/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> >> On 07.06.2007 23:12, Robert Dober wrote:
> >> > On 6/7/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> >> >> On 07.06.2007 21:41, Robert Dober wrote:
> >> >> > On 6/7/07, Robert Klemme <shortcutter@googlemail.com> wrote:
That's a dialog, right, I wonder if OP lost interest or did I just
hitchhike another thread?

let us see what I came up with under your tutorship.

require 'test/unit'
class Serial

  def initialize(*init, &f)
    @init = init
    @f = f
    @arity = f.arity
  end

  def get_some( some = nil, &b)
    current = @init.dup
    if some && b.nil? then
      r = @init.dup
      (some - r.size).times do
        current = compute_next( current )
        r << current.last
      end
      r
    else
      a = b.arity
      loop do
        break if some && ( some -= 1 ) < 0
        b[ *current.first( a ) ]
        current = compute_next( current )
      end
      self
    end
  end

  private
  def compute_next current
    (current + Array( @f[*current] ) ).last @arity
  end
end
if __FILE__ == $0 then

  class Testee < Test::Unit::TestCase
    def test_1
      s1 = Serial.new 0 do |x| x+1 end
      assert_equal [*0..3], s1.get_some( 4 )
      a = []
      s1.get_some{ |x| a  << x; break if x > 10 }
      assert_equal [*0..11], a
    end # def test_1

    def test_2
      f = Serial.new 1, 1 do |x, y| x + y end
      assert_equal [1,1,2,3,5,8], f.get_some(6)
      a = []
      f.get_some{ |x| a  << x; break if x > 10 }
      assert_equal [1,1,2,3,5,8,13], a
      a = []
      f.get_some(4){ |x| a.unshift x }
      assert_equal [3,2,1,1], a
    end # def test_2


    def test_3
      f = Serial.new 0, 0, 1 do |a, b, c| 3*a + 2*b + c end
      assert_equal [0,0,1,1,3,8,17,42,100], f.get_some(9)
    end # def test_3
  end # class Testee < Test::Unit::TestCase
end

Thanks again

Robert
-- 
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw