Feature #5899
chaining comparsions.
| Status: | Feedback | Start date: | 01/16/2012 | |
|---|---|---|---|---|
| Priority: | Normal | Due date: | ||
| Assignee: |  matz (Yukihiro Matsumoto) |
% Done: | 0% |
|
| Category: | Joke | |||
| Target version: | - |
Description
Migration from python to ruby is problematic because ruby lacks certain features.
Most important python advantage is chained comparison
We must wrap every comparison like described below.
puts "yes" if 1<2<3<4
class Fixnum
def <(a)
((self<=>a)==-1)&&a
end
end
class FalseClass
def <(a)
false
end
end
History
Updated by Anonymous 4 months ago
Ondrej Bilka wrote in post #1041080:
> Issue #5899 has been reported by Ondrej Bilka.
>
> ----------------------------------------
> Feature #5899: chaining comparsions.
> https://bugs.ruby-lang.org/issues/5899
>
> puts "yes" if 1<2<3<4
>
+1
--
Posted via http://www.ruby-forum.com/.
Updated by kernigh (George Koehler) 4 months ago
What is a good way to do chained comparison in Ruby?
My best attempt, so far, is
[1, 2, 3, 4].each_cons(2).all? {|a, b| a < b}
Updated by naruse (Yui NARUSE) 4 months ago
- Status changed from Open to Assigned
- Assignee set to matz (Yukihiro Matsumoto)
Updated by matz (Yukihiro Matsumoto) about 1 month ago
- Status changed from Assigned to Feedback
I don't think changing "1 < b < 4" to "1 < b && b < 4" is that hard task.
I am not sure it's worth allowing confusing "false < 4".
Matz.
Updated by neleai (Ondrej Bilka) about 1 month ago
On Sun, Apr 01, 2012 at 02:30:31AM +0900, matz (Yukihiro Matsumoto) wrote:
>
> Issue #5899 has been updated by matz (Yukihiro Matsumoto).
>
> Status changed from Assigned to Feedback
>
> I don't think changing "1 < b < 4" to "1 < b && b < 4" is that hard task.
> I am not sure it's worth allowing confusing "false < 4".
As false goes I would like to define sentinels by inheriting from FalseClass which is separate feature.
>
> Matz.
>
> ----------------------------------------
> Feature #5899: chaining comparsions.
> https://bugs.ruby-lang.org/issues/5899#change-25543
>
> Author: neleai (Ondrej Bilka)
> Status: Feedback
> Priority: Normal
> Assignee: matz (Yukihiro Matsumoto)
> Category: Joke
> Target version:
>
>
> Migration from python to ruby is problematic because ruby lacks certain features.
> Most important python advantage is chained comparison
> We must wrap every comparison like described below.
>
> puts "yes" if 1<2<3<4
>
> class Fixnum
> def <(a)
> ((self<=>a)==-1)&&a
> end
> end
> class FalseClass
> def <(a)
> false
> end
> end
>
>
>
>
> --
> http://bugs.ruby-lang.org/
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