From: myron.marston@...
Date: 2015-05-01T22:56:54+00:00
Subject: [ruby-core:69055] [Ruby trunk - Bug #11113] Time ranges cannot be used in case statements in 1.9+ but they could in 1.8.7

Issue #11113 has been updated by Myron Marston.


> The "can't iterate" error is simply because Time is float-based: there is no succ number.

Floats don't have a `succ` method, and yet `(2.3...3.2) === 3.0` works just fine.  Actually, I'm surprised that `succ` is used for `===` at all...it implies that `===` is a `O(N)` operation over the size of the range.  Seems like something like `range.begin < other && range.end > other` would perform better (constant time) and avoid this problem.  I haven't looked into the implementation of `cover?` but is that basically what it does internally?

----------------------------------------
Bug #11113: Time ranges cannot be used in case statements in 1.9+ but they could in 1.8.7
https://bugs.ruby-lang.org/issues/11113#change-52308

* Author: Myron Marston
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 1.9.2, 1.9.3, 2.0, 2.1, 2.2
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
Given this script:

```ruby
range = (Time.now - 1000)...(Time.now + 1000)

case Time.now
when range then puts "in range"
else puts "not in range"
end
```

I'd expect it to print "in range".  This worked on 1.8.7:

```
$ ruby -v time_range_problem.rb
ruby 1.8.7 (2013-12-22 patchlevel 375) [i686-darwin12.5.0]
in range
```

...but raises an exception in 1.9.2, 1.9.3, 2.0, 2.1 and 2.2:

```
time_range_problem.rb:4:in `each': can't iterate from Time (TypeError)
        from time_range_problem.rb:4:in `include?'
        from time_range_problem.rb:4:in `include?'
        from time_range_problem.rb:4:in `==='
        from time_range_problem.rb:4:in `<main>'
```

It looks like `Range#===` is broken.  Given that `===` is a standard ruby protocol, I would not expect a built-in type to raise an error like this.  IMO, `===` should either return true or false but should not raise an error.  We rely upon `===` in RSpec to do matching and this behavior means that if users pass us a time range, things blow up.  See https://github.com/rspec/rspec-mocks/issues/938 for an example.



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