Bug #1792: Fixnum#& 等が、Rational などを受けつける

• Status: Closed
• Assignee: mrkn (Kenta Murata)
• Target version: 2.0.0
• ruby -v: -

[tadf (tadayoshi funaba)]

=begin
1 & 1.5 がエラーになるので、
1 & Rational(3,2)
や
1 & BigDecimal('1.5')
もエラーにすべきかもしれません。
=end

[ujihisa (Tatsuhiro Ujihisa)]

• Status changed from Open to Assigned
• Assignee set to matz (Yukihiro Matsumoto)

=begin

=end

[ko1 (Koichi Sasada)]

これはどうしましょうか．

[matz (Yukihiro Matsumoto)]

• ruby -v changed from ruby 1.9.2dev (2009-07-19 trunk 24205) [i686-linux] to -

まつもと ゆきひろです

In message "Re: [ruby-core:36972] [Ruby 1.9 - Bug #1792] Fixnum#& 等が、Rational などを受けつける"
on Sat, 11 Jun 2011 14:54:43 +0900, Koichi Sasada [e-mail] writes:

|Issue #1792 has been updated by Koichi Sasada.
|
|これはどうしましょうか．

じゃ、エラーってことで。

[mrkn (Kenta Murata)]

これは 1.9.3 にバックポートしても良いですか？

[kosaki (Motohiro KOSAKI)]

これは 1.9.3 にバックポートしても良いですか？

以下はどのくら深刻なのでしょうか。

1 & 1.5 がエラーになるので、
1 & Rational(3,2)
や
1 & BigDecimal('1.5')
もエラーにすべきかもしれません。

freeze 後に仕様変更的な修正を入れるのは可能なら避けたいという思いがあります。
もし仮に修正漏れがあり、1.9.4で再fixとなると、エンドユーザ視点では1.9.2, 1.9.3, 1.9.4で
それぞれ微妙に挙動が異なることになり迷惑だからです。

しかし、1) 修正に自信がある、または 2) 重要度的に外せれない ということであれば反対はしません。

[mrkn (Kenta Murata)]

• Status changed from Assigned to Closed

むらたです。

そこまで重要ではないと思うので、バックポートはしないことにします。

[naruse (Yui NARUSE)]

• Status changed from Closed to Assigned
• Assignee changed from matz (Yukihiro Matsumoto) to mrkn (Kenta Murata)

これの影響で以下のようなエラーが出ています。
2) Error:
test_num2long(TestNumeric):
TypeError: can't convert Object into Integer for bitwise arithmetic
/home/naruse/ruby/test/ruby/test_numeric.rb:227:in &' /home/naruse/ruby/test/ruby/test_numeric.rb:227:in test_num2long'

[mrkn (Kenta Murata)]

• Status changed from Assigned to Closed

ごめんなさいごめんなさい。
r33113 で修正しました。

[naruse (Yui NARUSE)]

散発的になってすいませんが、RubySpecも追従よろしくお願いします

[ko1 (Koichi Sasada)]

Is it intentional?

class IntegerMimic
def initialize n
@n = n
end

def to_int
@n
end
end

obj = IntegerMimic.new(10)

%w(& | ^).each{|sym|
p sym
begin
p(3.send(sym, obj))
rescue => e
p e
end
}

#=>
ruby 1.9.4dev (2011-09-11 trunk 33248) [i386-mswin32_100]
"&"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>
"|"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>
"^"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>

(2011/08/29 7:25), Kenta Murata wrote:

Issue #1792 has been updated by Kenta Murata.

Status changed from Assigned to Closed

ごめんなさいごめんなさい。
r33113 で修正しました。

---

Bug #1792: Fixnum#& 等が、Rational などを受けつける
http://redmine.ruby-lang.org/issues/1792

Author: tadayoshi funaba
Status: Closed
Priority: Normal
Assignee: Kenta Murata
Category:
Target version: 1.9.x
ruby -v: -

=begin
1 & 1.5 がエラーになるので、
1 & Rational(3,2)
や
1 & BigDecimal('1.5')
もエラーにすべきかもしれません。
=end

--
// SASADA Koichi at atdot dot net

[ko1 (Koichi Sasada)]

I find out that bitwise operation doesn't call coerce.
How to make mimic Integer class?

class IntegerMimic
def initialize n
@n = n
end

def to_int
p :to_int
@n
end

def coerce obj
p :coerce
[obj, @n]
end
end

obj = IntegerMimic.new(10)

%w(+ - * / % & | ^).each{|sym|
p sym
begin
p(3.send(sym, obj))
rescue => e
p e
end
}

END
#=>
ruby 1.9.4dev (2011-09-11 trunk 33248) [i386-mswin32_100]
"+"
:coerce
13
"-"
:coerce
-7
"*"
:coerce
30
"/"
:coerce
0
"%"
:coerce
3
"&"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>
"|"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>
"^"
#<TypeError: can't convert IntegerMimic into Integer for bitwise arithmetic>

#=>
ruby 1.8.7 (2008-08-11 patchlevel 72) [i386-cygwin]
"+"
:coerce
13
"-"
:coerce
-7
"*"
:coerce
30
"/"
:coerce
0
"%"
:coerce
3
"&"
:to_int
2
"|"
:to_int
11
"^"
:to_int
9

--
// SASADA Koichi at atdot dot net

[cjheath (Clifford Heath)]

On 13/09/2011, at 9:27 AM, SASADA Koichi wrote:

I find out that bitwise operation doesn't call coerce.
How to make mimic Integer class?

The short answer: You can't.

The long answer:

You can imitate some of the behaviour of Integers, but when you
get into hashing and numeric operations, the different Ruby
interpreters all have different shortcuts that prevent your custom
code from being called.

See this post for more information:
http://blog.rubybestpractices.com/posts/rklemme/019-Complete_Numeric_Class.html

And a discussion thread that I started:
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/381087

Clifford Heath.

[mrkn (Kenta Murata)]

• Status changed from Closed to Open

I reopen this ticket because I rethink [ruby-core:39491] is bug.
But, unfortunately, I don't know how to fix this.
Using to_int cannot fix the original problem.
May Numeric#coerce is used for bitwise operation?

[matz (Yukihiro Matsumoto)]

Hi,

In message "Re: [ruby-core:39540] [Ruby 1.9 - Bug #1792][Open] Fixnum#& 等が、Rational などを受けつける"
on Wed, 14 Sep 2011 13:28:57 +0900, Kenta Murata [e-mail] writes:

|I reopen this ticket because I rethink [ruby-core:39491] is bug.
|But, unfortunately, I don't know how to fix this.
|Using to_int cannot fix the original problem.
|May Numeric#coerce is used for bitwise operation?

Using coerce is OK for me. But it should cause NoMethodError when
implemented naively. That might cause confusion.

						matz.

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Assigned

[mrkn (Kenta Murata)]

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

This issue was solved with changeset r38560.
tadayoshi, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• include/ruby/intern.h: add the prototype declaration of
  rb_num_coerce_bit.

• numeric.c (rb_num_coerce_bit): the new coerce function for bitwise
  binary operation.

• bignum.c (rb_big_and): use coerce to convert the argument, which isn't
  a Fixnum nor a Bignum, to the corresponding Integer object so that
  bitwise operations can support Integer-mimic objects.
  [Bug #1792] [ruby-core:39491]

• bignum.c (rb_big_or): ditto.

• bignum.c (rb_big_xor): ditto.

• numeric.c (bit_coerce): ditto.

• numeric.c (fix_and): ditto.

• numeric.c (fix_or): ditto.

• numeric.c (fix_xor): ditto.

• test/ruby/test_integer.rb: add tests for the above changes.

• test/ruby/test_bignum.rb: ditto.