From: Ray Bovet <Ray@...>
Date: 2011-02-02T04:34:45+09:00
Subject: Re: Ruby Range issues

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Thanks for the comments, Robert.

I agree that .succ for a Time is not obvious (there actually *is* a .succ
method for Time in 1.9.2 although it reports that it is deprecated), but I'd
still like to be able to use a specific step value.  It may be that your
wrapping suggestion is the best way forward, but I would think a lot of
people might want to be able to step through time intervals.

On the second issue, you only show the results with two dots.  What I was
concerned about was when you use three dots in order to exclude the endpoint
of the range.  In both 1.8.7 and 1.9.2p136 you only get 1.0 and 3.0.  It
appears that it first converts the end points to Integer before doing the
end comparison.  Here's an example in 1.9.2 showing both the 2 dot and the 3
dot versions:

irb
ruby-1.9.2-p136 :001 > ( 1.0 .. 5.01).step(2).to_a
 => [1.0, 3.0, 5.0]
ruby-1.9.2-p136 :002 > ( 1.0 ... 5.01).step(2).to_a
 => [1.0, 3.0]




On Tue, Feb 1, 2011 at 7:33 AM, Ray Bovet <Ray@bovet.org> wrote:

> Since I haven't posted to this group in the past 5 years or so, let me
> start by saying how much I enjoy using Ruby!  My comments below reflect my
> desire to see a couple of small issues improved in this extraordinary
> language!
>
>
> The first is a requested feature (which works in 1.8.7 but not in
> 1.9.2p136), while the second appears to me to be a bug that exists in both
> 1.8.7 and 1.9.2:
>
> 1. Range.step says (per PickAxe 3) that it works with range elements that
> support .succ, or with numbers.  It would be nice to have it work with
> elements that support .succ, /or with elements that support adding a number
> to them/.  This would allow stepping through time ranges, for example.
>
> 2. Range.step where the end is specified to be excluded ( '...') on floats
> seems to exclude the last value that should be included.  For example:
>    ( 1.0 ... 5.01).step( 2) {|x| puts x}
>    outputs 1.0 and 3.0 but not 5.0.
>    Interestingly, ( 1.0 ... 5.01).cover?( 5.0) returns true, as it should!
>
> *Ray Bovet*
> **
>
>
>

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