[#42344] [ruby-trunk - Feature #5964][Open] Make Symbols an Alternate Syntax for Strings — Tom Wardrop <tom@...>

23 messages 2012/02/03

[#42443] [ruby-trunk - Bug #5985][Open] miniruby skews "make benchmark" results — Eric Wong <normalperson@...>

21 messages 2012/02/08

[#42444] [ruby-trunk - Bug #5986][Open] Segmentation Fault — Luis Matta <levmatta@...>

16 messages 2012/02/08

[#42471] [ruby-trunk - Feature #5995][Open] calling io_advise_internal() in read_all() — Masaki Matsushita <glass.saga@...>

20 messages 2012/02/10

[#42560] [ruby-trunk - Bug #6011][Open] ruby-1.9.3-p0/lib/webrick/utils.rb:184: [BUG] Segmentation fault — Vit Ondruch <v.ondruch@...>

12 messages 2012/02/13

[#42579] [ruby-trunk - Bug #6012][Open] Proc#source_location also return the column — Roger Pack <rogerpack2005@...>

14 messages 2012/02/14

[#42685] [ruby-trunk - Bug #6036][Open] Test failures in Fedora Rawhide/17 — Bohuslav Kabrda <bkabrda@...>

14 messages 2012/02/16

[#42697] [ruby-trunk - Bug #6040][Open] Transcoding test failure: Big5 to UTF8 not defined (MinGW) — Luis Lavena <luislavena@...>

10 messages 2012/02/16

[#42813] [ruby-trunk - Feature #6065][Open] Allow Bignum marshalling/unmarshalling from C API — Martin Bosslet <Martin.Bosslet@...>

22 messages 2012/02/23

[#42815] [ruby-trunk - Bug #6066][Open] Fix "control may reach end of non-void function" warnings for clang — Eric Hodel <[email protected]>

15 messages 2012/02/23

[#42857] [ruby-trunk - Feature #6074][Open] Allow alias arguments to have a comma — Thomas Sawyer <transfire@...>

20 messages 2012/02/24

[#42891] [ruby-trunk - Feature #6083][Open] Hide a Bignum definition — Koichi Sasada <redmine@...>

23 messages 2012/02/25

[#42906] [ruby-trunk - Bug #6085][Open] Treatment of Wrong Number of Arguments — Marc-Andre Lafortune <ruby-core@...>

14 messages 2012/02/25

[#42949] [ruby-trunk - Bug #6089][Open] Test suite fails with OpenSSL 1.0.1 — Vit Ondruch <v.ondruch@...>

13 messages 2012/02/26

[ruby-core:42611] Re: [ruby-trunk - Bug #6020] Unexpected is_a/kind_of behaviour

From: Peter Vandenabeele <peter@...>
Date: 2012-02-14 10:52:44 UTC
List: ruby-core #42611
On Tue, Feb 14, 2012 at 11:41 AM, Alex N <[email protected]> wrote:

>
> Issue #6020 has been updated by Alex N.
>
>
> =begin
> well, at least (({Integer.is_a?(Integer) #=> true})).



TL;DR : use `is_a?` on an _object_ of the class, not on the class itself.

Long version:

The confusion is that is_a? checks if the _object_ is of class Integer,
not the Integer _class_.

So.

$ irb
1.9.3p0 :001 > i = 12
 => 12
1.9.3p0 :002 > i.class
 => Fixnum

i is an _object_ of the Fixnum class.

1.9.3p0 :003 > i.is_a?(Integer)
 => true

yes, the _object_ i is an Integer ...

1.9.3p0 :004 > i.is_a?(Fixnum)
 => true

... and also a Fixnum

1.9.3p0 :005 > Integer.class
 => Class
1.9.3p0 :006 > Integer.is_a?(Integer)
 => false

but the _class_ Integer is not an Integer
(because Class does not inherit from Integer).

1.9.3p0 :007 > Class.ancestors
 => [Class, Module, Object, Wirble::Shortcuts, PP::ObjectMixin, Kernel,
BasicObject]

Class only inherits from Module, Object and BasicObject and mixes in some
additional functionality.

HTH,

Peter


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