Enumerable#prev　#chino_to_enum / count_lib_v2 / Fiber

.md

info

• Count_lib_v2　　/　prev　peek
• chino_to_enum　 / prev

この三つは非常に低速　nextの数百倍～

この実装はpeekだけの速度を犠牲にした （ rewind の使用

基本はseekを使い、前回のnextの結果を得るほうを使う

prevをリアルタイムで使う場合は、Array_cycle、またはFocusを使う

---

count_lib_v2.rb

( obsolete Enumerableで全部書いた )

以前500行くらいのlambda無双で書いたコードをFiberにして小さくしたやつ

---

chino_to_enum

メニューSelect等で使う場合､最初に100回くらい先にnext廻しとけば

cc = 0.step(sstr.size-1,1).cycle.chino_to_enum
(100*sstr.size.-(0)).times { cc.next }

最初からcc.prev が動く

この程度をバグじゃなくて仕様扱いに出来るなら

chino_to_enum使うと楽

chino_to_enumはEnumerableすべてで seek prev を使えるようにしてるから

prevを現実的な速度で実装すれば利点はあるかも

---

Array_cycle

プラス・マイナスの添え字で配列にアクセスする事を前提のフォーカス Array_cycle

添え字以外のフォーカスには使えない

---

Focus

class Focus は、どの言語でも出来る普通の実装

chino_cocoa_to_enum.rb

Count_lib_v1,v2 の後継

Array_cycle.rb

class Array_cycle
  attr_accessor :size 
  def initialize size
    @size = size
    rewind
  end
  def rewind
    @aa = [*0..size.-(1)].cycle
    @bb = [*-size..-1].reverse.cycle
  end
  def seek
    @seek
  end
  def peek
    @aa.peek + @bb.peek
  end
  def next
    @seek = @aa.next
  end
  def prev
    @bb.next
  end
end

benchmark__.rb

# require_relative "./Count_lib_v2"
# require_relative "./chino_to_enum"
# require_relative "./Array_cycle"
# require_relative "./Focus"



require "Benchmark"
Benchmark.bm do|x| N = 5000
  enum = 0.step(10000,1)
  p "-chino-"
  ch = enum.chino_to_enum
  x.report :next do  N.times do ch.next end end
  x.report :peek do  N.times do ch.peek end end
  x.report :prev do  N.times do ch.prev end end
  x.report :seek do  N.times do ch.seek end end
  p "-Count_lib_v2-"
  ch = Count_lib_v2.new( start: 0 , limit: 10000 , add: 1 )
  x.report :next do  N.times do ch.next end end
  x.report :peek do  N.times do ch.peek end end
  x.report :prev do  N.times do ch.prev end end
  x.report :seek do  N.times do ch.seek end end
  p "-Array_cycle-"
  ch = Array_cycle.new 10000
  x.report :next do  N.times do ch.next end end
  x.report :peek do  N.times do ch.peek end end
  x.report :prev do  N.times do ch.prev end end
  x.report :seek do  N.times do ch.seek end end
  p "-Focus-"
  ch = Focus.new 0 , 10000
  x.report :next do  N.times do ch.next end end
  x.report :peek do  N.times do ch.peek end end
  x.report :prev do  N.times do ch.prev end end
  x.report :seek do  N.times do ch.seek end end

end



#        user     system      total        real
# "-chino-"
# next  0.000000   0.000000   0.000000 (  0.006090)
# peek  0.015000   0.000000   0.015000 (  0.000608)
# prev 15.094000   0.063000  15.157000 ( 15.407540)
# seek  0.000000   0.000000   0.000000 (  0.000936)
# "-Count_lib_v2-"
# next  0.000000   0.000000   0.000000 (  0.003162)
# peek 17.172000   0.156000  17.328000 ( 17.455832)
# prev  8.812000   0.094000   8.906000 (  9.147972)
# seek  0.000000   0.000000   0.000000 (  0.000700)
# "-Array_cycle-"
# next  0.000000   0.000000   0.000000 (  0.003066)
# peek  0.016000   0.000000   0.016000 (  0.001328)
# prev  0.000000   0.000000   0.000000 (  0.003297)
# seek  0.000000   0.000000   0.000000 (  0.001031)
# "-Focus-"
# next  0.000000   0.000000   0.000000 (  0.001024)
# peek  0.000000   0.000000   0.000000 (  0.000863)
# prev  0.000000   0.000000   0.000000 (  0.001173)
# seek  0.000000   0.000000   0.000000 (  0.000654)

chino_cocoa_to_enum.rb

module Enumerable
  def chino_to_enum
    enum = Enumerator.new do |y|
      each_with_index do |m,i|
        y.yield enum._state = m
        enum._prev_count = i
      end
    end
    enum.extend Module.new{ attr_accessor :_prev_count , :_state }
    enum._prev_count = 0
    enum
  end
  def seek
    _state
  end
  def prev
    rewind
    _prev_count.times do self.next end
    peek
  end
  def cycle_rev
    (self.to_a + self.to_a.reverse[1...-1]).cycle
  end
  def cocoa_to_enum
    enum = chino_to_enum
    def enum.next ; super
    rescue StopIteration
      _state
    end
    return enum
  end
end



# p x = 0.step(2,1).cycle_rev
# p x = 0.step(2,1)
N = 5
ch = 0.step(N,1).chino_to_enum
p "-chino_to_enum-"
print"next:"; N.times { print ch.next , " " } ; puts
print"prev:"; N.times { print ch.prev , " " } ; puts
ch.rewind
print"next:"; N.-(1).times { print ch.next , " " } ; puts
print"peek:"; N.times { print ch.peek , " " } ; puts

NN = 12
ch = 0.step(N,1).cocoa_to_enum
p "-cocoa_to_enum-"
print"next:"; NN.times { print ch.next , " " } ; puts
print"prev:"; NN.times { print ch.prev , " " } ; puts
ch.rewind
print"next:"; N.-(1).times { print ch.next , " " } ; puts
print"peek:"; NN.times { print ch.peek , " " } ; puts


ch = 0.step(4,1).cycle_rev.chino_to_enum
p "-cycle_rev-"
print"next:"; NN.times { print ch.next , " " } ; puts
print"prev:"; NN.times { print ch.prev , " " } ; puts
ch.rewind
print"next:"; NN.times { print ch.next , " " } ; puts
print"peek:"; NN.times { print ch.peek , " " } ; puts


# "-chino_to_enum-"
# next:0 1 2 3 4 
# prev:3 2 1 0 0 
# next:0 1 2 3 
# peek:4 4 4 4 4 
# "-cocoa_to_enum-"
# next:0 1 2 3 4 5 5 5 5 5 5 5 
# prev:5 4 3 2 1 0 0 0 0 0 0 0 
# next:0 1 2 3 
# peek:4 4 4 4 4 4 4 4 4 4 4 4 
# "-cycle_rev-"
# next:0 1 2 3 4 3 2 1 0 1 2 3 
# prev:2 1 0 1 2 3 4 3 2 1 0 0 
# next:0 1 2 3 4 3 2 1 0 1 2 3 
# peek:4 4 4 4 4 4 4 4 4 4 4 4 

count_lib_v2.rb

module Count_lib_v2_m
  attr_reader :enum , :count , :start , :limit , :add
  def initialize start: , limit: , add:
    @start = start ; @limit = limit ; @add = add
    @enum  = @start.step(@limit,@add)
    @argv  = [@start , @limit , @add]
    rewind
  end
  def fiber_yield      # ovar lide
    @fib = Fiber.new do
      fiber_yield_sub
      Fiber.yield limit while true
    end # f
  end
  def fiber_yield_sub
    enum.each_with_index do | m , i |
      @count = i
      Fiber.yield m
    end
  end
  def rewind
    @count = 0
    @seek  = 0
    fiber_yield
  end # df

  def peek
    ret = @fib.resume
    count_tmp = @count
    rewind
    count_tmp.times do self.next end
    ret
  end
  def seek ; @seek ; end
  def next
    @seek = @fib.resume
  end
  def prev
    count_tmp = @count
    rewind
    count_tmp.times do self.next end
    @seek
  end
  def take n
    n.times.map do self.next end
  end
end
class Count_lib_v2
  include Count_lib_v2_m
end
class Count_lib_v2_rev
  include Count_lib_v2_m
  undef_method  :prev  # muzui mi ji ssou
  def fiber_yield
    @fib = Fiber.new do | x |
      fiber_yield_sub
      limit.-(1).step(start+1,-add).each.with_index @count do | m , i |
        @count = i
        Fiber.yield m
      end
      rewind
      @fib.resume
    end # f
  end # d
end
class Count_lib_v2_cycle
  include Count_lib_v2_m
  undef_method  :prev  # muzui mi ji ssou
  def fiber_yield
    @fib = Fiber.new do | x |
      fiber_yield_sub
      rewind
      @fib.resume
    end # f
  end # d
end

count_lib_v2__how__to__.rb

ch = Count_lib_v2.new( start: 0 , limit: 3 , add: 1 )
p "-Count_lib_v2-"
print"next:"; 5.times { print ch.next , " " } ; puts
print"prev:"; 5.times { print ch.prev , " " } ; puts
ch.rewind
print"next:"; 5.times { print ch.next , " " } ; puts
print"peek:"; 5.times { print ch.peek , " " } ; puts

ch = Count_lib_v2_rev.new( start: 0 , limit: 3 , add: 1 )
p "-Count_lib_v2_rev-"
12.times { print ch.next , " " } ; puts
#12.times { print ch.prev , " " } ; puts
ch.rewind
12.times { print ch.next , " " } ; puts

ch = Count_lib_v2_cycle.new( start: 0 , limit: 3 , add: 1 )
p "-Count_lib_v2_cycle-"
12.times { print ch.next , " " } ; puts
#12.times { print ch.prev , " " } ; puts
ch.rewind
12.times { print ch.next , " " } ; puts

p "-Count_lib_v2_cycle loop_wait -"
ch.rewind
12.times { |i|
  if (3..5).include? i
    print ch.peek , " " ; next
  end
  print ch.next , " "
} ; puts
p ch.take(15)



# "-Count_lib_v2-"
# next:0 1 2 3 3 
# prev:2 1 0 0 0 
# next:0 1 2 3 3 
# peek:3 3 3 3 3 
# "-Count_lib_v2_rev-"
# 0 1 2 3 2 1 0 1 2 3 2 1 
# 0 1 2 3 2 1 0 1 2 3 2 1 
# "-Count_lib_v2_cycle-"
# 0 1 2 3 0 1 2 3 0 1 2 3 
# 0 1 2 3 0 1 2 3 0 1 2 3 
# "-Count_lib_v2_cycle loop_wait -"
# 0 1 2 3 3 3 3 0 1 2 3 0 
# [1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3]

enum_prev.rb

module Enumerable
  def chino_to_enum
    fib = Enumerator.new do |y|
      each_with_index do |m,i|
        y.yield fib._state = m
        fib._prev_count = i
      end
    end
    fib.extend Module.new{ attr_accessor :_prev_count , :_state }
    _prev_count ||= 0
    fib
  end
  def seek
    _state
  end
  def prev
    rewind
    _prev_count.times do self.next end
    peek
  end

end

focus.rb

class Focus
  attr_reader :focus , :size
  def initialize focus , size
    @focus = focus
    @size  = size
  end
  def seek
    focus
  end
  def peek
    (focus+1) % size
  end
  def next
    @focus = (focus+1) % size
  end
  def prev
    @focus = (focus-1) % size
  end
end


class Focus_Array
  attr_reader :focus , :ar
  def initialize ar
    @ar= ar
    @focus = 0
  end
  def size
    ar.size
  end
  def peek_num
    focus
  end
  def seek
    ar[ focus ]
  end
  def peek
    ar[ (focus+1) % ar.size ]
  end
  def next
    ar[ @focus = (focus+1) % ar.size ]
  end
  def prev
    ar[ @focus = (focus-1) % ar.size ]
  end
end