Bug #4994
DelegateClass don't find extern global public method in 1.9.2
| Status: | Rejected | Start date: | 07/08/2011 | |
|---|---|---|---|---|
| Priority: | Normal | Due date: | ||
| Assignee: | - | % Done: | 0% |
|
| Category: | lib | |||
| Target version: | 1.9.2 | |||
| ruby -v: | ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux] |
Description
How to reproduce:
<pre>
require 'delegate'
require 'pp'
def test_that?(str)
str.size > 0
end
class String2 < DelegateClass(String)
def initialize(*param)
@s = String.new(*param)
super(@s)
end
def dummy
test_that?(@s)
end
end
s2 = String2.new("pipo")
pp s2.dummy
</pre>
The code above works under 1.9.1 and 1.8 but not under 1.9.2
* ruby1.9.1 -v => ruby 1.9.1p378 (2010-01-10 revision 26273) [x86_64-linux]
* ruby1.8 -v => ruby 1.8.7 (2010-01-10 patchlevel 249) [x86_64-linux]
* ruby -v => ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
error message:
<pre>
!ruby draft/tdelegate.rb
draft/tdelegate.rb:15:in `dummy': undefined method `test_that?' for "pipo":String2 (NoMethodError)
from draft/tdelegate.rb:21:in `<main>'
shell returned 1
</pre>
History
Updated by nobu (Nobuyoshi Nakada) 11 months ago
- Status changed from Open to Rejected
It's a spec change for [ruby-dev:39154].
* Delegator now tries to forward all methods as possible,
* but not for private methods, and
* test_that? is a private method.
Probably, it would need a way to tell how the method is called in method_missing.
Updated by sylvain303 (Sylvain Viart) 10 months ago
Sorry, but links are in Japanese.
I can read the code, but not why the DelegateClass shouldn't search the toplevel method, any more?
Could you translate or post a link to an English doc?
For the correction you suggest, I've wrote this code:
I don't like this usage as a Delegation. May be I missed something.
Edited: Wrong solution, for this method_missing() see comment after
<pre>
require 'delegate'
require 'pp'
def test_that?(str)
str.size > 0
end
class String2 < DelegateClass(String)
def initialize(*param)
@s = String.new(*param)
super(@s)
end
def dummy
test_that?(@s)
# this method is really missing
bla()
end
def method_missing(m, *args, &block)
begin
Object.send(m, *args, &block)
rescue NameError =>e
# doesn't work with NoMethodError, it loops
raise "no method found: '#{m}'"
end
end
end
s2 = String2.new("pipo")
# test Delegated method
pp s2.size
# call with method_missing()
pp s2.dummy
</pre>
output (ruby -v ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux])
<pre>
:!ruby draft/tdelegate.rb
4
draft/tdelegate.rb:24:in `rescue in method_missing': no method found: 'bla' (RuntimeError)
from draft/tdelegate.rb:20:in `method_missing'
from draft/tdelegate.rb:16:in `dummy'
from draft/tdelegate.rb:32:in `<main>'
</pre>
Updated by sylvain303 (Sylvain Viart) 10 months ago
The Issue topic could be rewritten: "DelegateClass don't lookup toplevel method in 1.9.2"
Reading and patching the delegate.rb:http://redmine.ruby-lang.org/projects/ruby-19/repository/entry/lib/delegate.rb I've found that it's related to BasicObject's behavior. DelegateClass somewhat inherit from BasicObject, not Object.
This issue follow the same pattern as #3768.
The documentation should be updated how to fix that (toplevel method resolution).
But may be, I'm still miss something about the new Spec about DelegateClass.
Updated by sylvain303 (Sylvain Viart) 10 months ago
Fixed DelegateClass with method_missing(), somewhat ugly right?
<pre>
require 'delegate'
def hello
:hello
end
class MyInt < DelegateClass(Integer)
def initialize(value)
@i = value
super(@i)
# I want some toplevel here
@hello = hello()
end
def method_missing(m, *args, &block)
if __getobj__.respond_to?(m)
__getobj__.__send__(m, *args, &block)
else
Object.send(m, *args, &block)
end
end
end
ii = MyInt.new(2)
puts p"should call Integer#to_si: #{ii}"
puts "ii.class=#{ii.class}"
</pre>
output ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
<pre>
should call Integer#to_si: 2
ii.class=MyInt
</pre>