Bug #8173: 2-arg form of Time.at can take a Time as either argument

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.1.0dev (2013-03-11 trunk 39724) [x86_64-darwin12.2.1]

[hasari (Hiro Asari)]

http://www.ruby-doc.org/core-2.0/Time.html#method-c-at shows 3 forms of invocation:

at(time) → time click to toggle source
at(seconds_with_frac) → time
at(seconds, microseconds_with_frac) → time

But the last form can take a Time as either argument (and converts to a numeric value represented by the number of seconds since the Epoch). If a Time is used as the second argument, the numeric value is then converted to microseconds to return a Time. (I hope that I'm making sense.)

irb(main):001:0> RUBY_DESCRIPTION
=> "ruby 2.1.0dev (2013-03-11 trunk 39724) [x86_64-darwin12.2.1]"
irb(main):002:0> t1=Time.at(10)
=> 1969-12-31 19:00:10 -0500
irb(main):003:0> t2=Time.at(t1,t1)
=> 1969-12-31 19:00:10 -0500
irb(main):004:0> t2.usec
=> 10

Is this intended behavior? If so, the documentation should be updated.

1.9.3 behaves the same way.

[akr (Akira Tanaka)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r39967.
Hiro, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• time.c (num_exact): use to_r method only if to_int method is
  available.
  [ruby-core:53764] [Bug #8173] reported by Hiro Asari.

[akr (Akira Tanaka)]

2013/3/27 hasari (Hiro Asari) [e-mail]:

Bug #8173: 2-arg form of Time.at can take a Time as either argument
https://bugs.ruby-lang.org/issues/8173

http://www.ruby-doc.org/core-2.0/Time.html#method-c-at shows 3 forms of invocation:

at(time) → time click to toggle source
at(seconds_with_frac) → time
at(seconds, microseconds_with_frac) → time

But the last form can take a Time as either argument (and converts to a numeric value represented by the number of seconds since the Epoch). If a Time is used as the second argument, the numeric value is then converted to microseconds to return a Time. (I hope that I'm making sense.)

irb(main):001:0> RUBY_DESCRIPTION
=> "ruby 2.1.0dev (2013-03-11 trunk 39724) [x86_64-darwin12.2.1]"
irb(main):002:0> t1=Time.at(10)
=> 1969-12-31 19:00:10 -0500
irb(main):003:0> t2=Time.at(t1,t1)
=> 1969-12-31 19:00:10 -0500
irb(main):004:0> t2.usec
=> 10

Is this intended behavior? If so, the documentation should be updated.

It is a bug.

Tanaka Akira

[hasari (Hiro Asari)]

Will this be backported to 1.9.x?

[akr (Akira Tanaka)]

2013/3/28 hasari (Hiro Asari) [e-mail]:

Issue #8173 has been updated by hasari (Hiro Asari).

Will this be backported to 1.9.x?

Currently I don't plan to request.

Tanaka Akira

[hasari (Hiro Asari)]

What is the reason not to?

[akr (Akira Tanaka)]

2013/3/28 hasari (Hiro Asari) [e-mail]:

Issue #8173 has been updated by hasari (Hiro Asari).

What is the reason not to?

Usually I don't consider backport until someone request (someone have trouble).

Tanaka Akira

[hasari (Hiro Asari)]

Can I request it? I would like to implement the intended, more correct behavior in JRuby.

[akr (Akira Tanaka)]

2013/3/28 hasari (Hiro Asari) [e-mail]:

Issue #8173 has been updated by hasari (Hiro Asari).

Can I request it? I would like to implement the intended, more correct behavior in JRuby.

You can.
See [ruby-core:52534].

Tanaka Akira