From: Yusuke ENDOH <mame@...>
Date: 2011-09-17T14:05:10+09:00
Subject: [ruby-core:39602] Re: [Ruby 1.9 - Bug #4576] Range#step miss the last value, if end-exclusive and has float number

Hello,

2011/9/17 Tanaka Akira <akr@fsij.org>:
> But in the following script, which changes "a...b" to "a..b" from the above
> script, the result length doesn't vary.
>
> % ./ruby -e '
> h = Hash.new(0)
> 1000.times {
> �a = rand
> �b = a+rand*10000
> �s = (b - a) / 10
> �l = (a..b).step(s).to_a.length
> �h[l] += 1
> }
> p h
> '
> {11=>1000}
>
> This is because we tried to consider float errors
> in Numeric#step for Ruby 1.8. �[ruby-dev:20163]


Maybe this "consideration" causes the following behavior:

  p (1.0..12.7).step(1.3).all? {|n| n <= 12.7 }  #=> false
  p (1.0..12.7).step(1.3).to_a
    #=> [1.0, 2.3, 3.6, 4.9, 6.2, 7.5, 8.8, 10.1, 11.4, 12.700000000000001]

Is this ok?
I guess the result length will vary if this is fixed simply.

-- 
Yusuke Endoh <mame@tsg.ne.jp>