[#43120] [ruby-trunk - Bug #6124][Open] What is the purpose of "fake" gems in Ruby — Vit Ondruch <v.ondruch@...>

27 messages 2012/03/07

[#43142] Questions about thread performance (with benchmark included) — Rodrigo Rosenfeld Rosas <rr.rosas@...>

A while ago I've written an article entitled "How Nokogiri and JRuby

10 messages 2012/03/08

[#43148] [ruby-trunk - Feature #6126][Open] Introduce yes/no constants aliases for true/false — Egor Homakov <homakov@...>

16 messages 2012/03/09

[#43238] [ruby-trunk - Feature #6130][Open] inspect using to_s is pain — Thomas Sawyer <transfire@...>

21 messages 2012/03/11

[#43313] [ruby-trunk - Feature #6150][Open] add Enumerable#grep_v — Suraj Kurapati <sunaku@...>

17 messages 2012/03/15

[#43325] [ruby-trunk - Bug #6154][Open] Eliminate extending WaitReadable/Writable at runtime — Charles Nutter <headius@...>

25 messages 2012/03/16

[#43334] [ruby-trunk - Bug #6155][Open] Enumerable::Lazy#flat_map raises an exception when an element does not respond to #each — Dan Kubb <dan.kubb@...>

9 messages 2012/03/16

[#43370] [ruby-trunk - Feature #6166][Open] Enumerator::Lazy#pinch — Thomas Sawyer <transfire@...>

15 messages 2012/03/17

[#43373] [ruby-trunk - Bug #6168][Open] Segfault in OpenSSL bindings — Nguma Abojo <git.email.address@...>

14 messages 2012/03/17

[#43454] [ruby-trunk - Bug #6174][Open] Fix collision of ConditionVariable#wait timeout and #signal (+ other cosmetic changes) — "funny_falcon (Yura Sokolov)" <funny.falcon@...>

10 messages 2012/03/18

[#43497] [ruby-trunk - Bug #6179][Open] File::pos broken in Windows 1.9.3p125 — "jmthomas (Jason Thomas)" <jmthomas@...>

24 messages 2012/03/20

[#43502] [ruby-trunk - Feature #6180][Open] to_b for converting objects to a boolean value — "AaronLasseigne (Aaron Lasseigne)" <aaron.lasseigne@...>

17 messages 2012/03/20

[#43529] [ruby-trunk - Bug #6183][Open] Enumerator::Lazy performance issue — "gregolsen (Innokenty Mikhailov)" <anotheroneman@...>

36 messages 2012/03/21

[#43543] [ruby-trunk - Bug #6184][Open] [BUG] Segmentation fault ruby 1.9.3p165 (2012-03-18 revision 35078) [x86_64-darwin11.3.0] — "Gebor (Pierre-Henry Frohring)" <frohring.pierrehenry@...>

8 messages 2012/03/21

[#43672] [ruby-trunk - Feature #6201][Open] do_something then return :special_case (include "then" operator) — "rosenfeld (Rodrigo Rosenfeld Rosas)" <rr.rosas@...>

12 messages 2012/03/26

[#43678] [ruby-trunk - Bug #6203][Open] Array#values_at does not handle ranges with end index past the end of the array — "ferrous26 (Mark Rada)" <markrada26@...>

15 messages 2012/03/26

[#43794] [ruby-trunk - Feature #6216][Open] SystemStackError backtraces should not be reduced to one line — "postmodern (Hal Brodigan)" <postmodern.mod3@...>

15 messages 2012/03/28

[#43814] [ruby-trunk - Feature #6219][Open] Return value of Hash#store — "MartinBosslet (Martin Bosslet)" <Martin.Bosslet@...>

20 messages 2012/03/28

[#43858] [ruby-trunk - Feature #6222][Open] Use ++ to connect statements — "gcao (Guoliang Cao)" <gcao99@...>

12 messages 2012/03/29

[#43904] [ruby-trunk - Feature #6225][Open] Hash#+ — "trans (Thomas Sawyer)" <transfire@...>

36 messages 2012/03/29

[#43951] [ruby-trunk - Bug #6228][Open] [mingw] Errno::EBADF in ruby/test_io.rb on ruby_1_9_3 — "jonforums (Jon Forums)" <redmine@...>

28 messages 2012/03/30

[#43996] [ruby-trunk - Bug #6236][Open] WEBrick::HTTPServer swallows Exception — "regularfry (Alex Young)" <alex@...>

13 messages 2012/03/31

[ruby-core:43179] [ruby-trunk - Bug #5304][Assigned] Array#pack handles objects for eg format 'E' differently than 1.8

From: Koichi Sasada <redmine@...>
Date: 2012-03-11 06:33:37 UTC
List: ruby-core #43179
Issue #5304 has been updated by Koichi Sasada.

Status changed from Open to Assigned
Assignee set to Kenta Murata

Please discuss with matz.
However, I assign this ticket to Murata-san, because matz will ignore assignment.

Murata-san:
  Please lead discussion about this issue.
  

----------------------------------------
Bug #5304: Array#pack handles objects for eg format 'E' differently than 1.8
https://bugs.ruby-lang.org/issues/5304

Author: Brian Ford
Status: Assigned
Priority: Normal
Assignee: Kenta Murata
Category: 
Target version: 
ruby -v: ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]


In 1.9, Array#pack when passed an object that defines #to_f and one of the Float formats raises a TypeError. This is a change from 1.8. The code in 1.9 calls rb_to_float()

# 1.9

VALUE
rb_to_float(VALUE val)
{
    if (TYPE(val) == T_FLOAT) return val;
    if (!rb_obj_is_kind_of(val, rb_cNumeric)) {
	rb_raise(rb_eTypeError, "can't convert %s into Float",
		 NIL_P(val) ? "nil" :
		 val == Qtrue ? "true" :
		 val == Qfalse ? "false" :
		 rb_obj_classname(val));
    }
    return rb_convert_type(val, T_FLOAT, "Float", "to_f");
}

The rb_to_float() imposes the (arbitrary) restriction that the object be kind of Numeric. The 1.8 pack code used rb_Float(), which merely requires the object respond to #to_f and return a Float.

The treatment of objects in 1.9 for the float formats is thus different than for eg the integer formats, where the object simply must respond to #to_int. The requirement that the object be a kind of Numeric breaks the uniform ducktyping and imposes an arbitrary and unnecessary type/class requirement.

Was this change intended, and if so, why? Apologies if this was discussed on ruby-core prior to the change; I could not find any discussion through searching.

The following code illustrates the issue:

o = Object.new

def o.to_int
  puts "to_int called"
  1
end

def o.to_f
  puts "to_f called"
  1.1
end

p [o].pack("I") # => "\001..." (depends on endianness)
p [o].pack("E") # => 1.8 - "<numbers>"; 1.9 - TypeError

$ ruby1.8.7 -v pack_test.rb 
ruby 1.8.7 (2011-02-18 patchlevel 334) [i686-darwin10.8.0]
to_int called
"\001\000\000\000"
to_f called
"\232\231\231\231\231\231\361?"

$ ruby1.9.2 -v pack_test.rb 
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]
to_int called
"\x01\x00\x00\x00"
pack_test.rb:14:in `pack': can't convert Object into Float (TypeError)
	from pack_test.rb:14:in `<main>'



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