* Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb)
@ 2009-09-15 11:50 Iñaki Baz Castillo
2009-09-15 11:59 ` Magnus Holm
0 siblings, 1 reply; 4+ messages in thread
From: Iñaki Baz Castillo @ 2009-09-15 11:50 UTC (permalink / raw)
To: rack-devel
Using Ruby1.9 there is an issue related to instance_eval() method
which behaves different than in 1.8. Let me show this example:
--------myapp.rb------------------------
class MyRack
MY_VAR = "helloooo"
def self.create
Rack::Builder.new do
map "/" do
puts "[1] MY_VAR = #{MY_VAR}" <----- [1] (line 20)
run Proc.new { |env|
puts "[2] MY_VAR = #{MY_VAR}" <----- [2] (line 22)
[ 200, {"Content-Type" => "text/plain"}, ["Yeah"] ]
}
end
end
end
end
rack_core = MyRack.create
Rack::Handler::Thin.run rack_core
----------------------------------------
This works great in Ruby1.8.
However, in Ruby1.9 I get this error:
/myapp.rb:20:in `block (2 levels) in core': uninitialized constant
Rack::Builder::MY_VAR (NameError)
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
`instance_eval'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
`initialize'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:46:in
`new'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:46:in
`map'
from /root/svn_local_copies/OpenXDMS/trunk/lib/rack/core.rb:41:in
`block in core'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
`instance_eval'
from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
`initialize'
If I remove line 20, then it would in runtime in line 22 (when "run"
is invoked for a incoming request).
The only solution for it to work in 1.9 is to add ALL the Module/Class
namespace for ALL the modules/classes:
Rack::Builder.new do
map "/" do
puts "[1] MY_VAR = #{::MyRack::MY_VAR}" <----- [1] (line 20)
run Proc.new { |env|
puts "[2] MY_VAR = #{::MyRack::MY_VAR}" <-----
[2] (line 22)
[ 200, {"Content-Type" => "text/plain"}, ["Yeah"] ]
}
end
end
It's VERY important to note that if I use "MyRack::MY_VAR" instead of
"::MyRack::MY_VAR" then it would *also* fail in Ruby1.9:
`block (2 levels) in core': uninitialized constant
Rack::Builder::MyRack (NameError)
It seems that using instance_eval in Ruby1.9 a class/module is just
looked for into the class/module executing the instance_eval and
doesn't look on top of it.
Regards.
--
Iñaki Baz Castillo
<ibc@aliax.net>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb)
2009-09-15 11:50 Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb) Iñaki Baz Castillo
@ 2009-09-15 11:59 ` Magnus Holm
2009-09-15 12:46 ` Iñaki Baz Castillo
0 siblings, 1 reply; 4+ messages in thread
From: Magnus Holm @ 2009-09-15 11:59 UTC (permalink / raw)
To: rack-devel
Also see http://coderrr.wordpress.com/2009/06/02/fixing-constant-lookup-in-dsls-in-ruby-1-9/
//Magnus Holm
On Tue, Sep 15, 2009 at 13:50, Iñaki Baz Castillo <ibc@aliax.net> wrote:
>
> Using Ruby1.9 there is an issue related to instance_eval() method
> which behaves different than in 1.8. Let me show this example:
>
> --------myapp.rb------------------------
> class MyRack
>
> MY_VAR = "helloooo"
>
> def self.create
> Rack::Builder.new do
> map "/" do
> puts "[1] MY_VAR = #{MY_VAR}" <----- [1] (line 20)
> run Proc.new { |env|
> puts "[2] MY_VAR = #{MY_VAR}" <----- [2] (line 22)
> [ 200, {"Content-Type" => "text/plain"}, ["Yeah"] ]
> }
> end
> end
> end
>
> end
>
>
> rack_core = MyRack.create
>
> Rack::Handler::Thin.run rack_core
> ----------------------------------------
>
>
> This works great in Ruby1.8.
>
> However, in Ruby1.9 I get this error:
>
>
> /myapp.rb:20:in `block (2 levels) in core': uninitialized constant
> Rack::Builder::MY_VAR (NameError)
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
> `instance_eval'
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
> `initialize'
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:46:in
> `new'
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:46:in
> `map'
> from /root/svn_local_copies/OpenXDMS/trunk/lib/rack/core.rb:41:in
> `block in core'
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
> `instance_eval'
> from /usr/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.0.0/lib/rack/builder.rb:29:in
> `initialize'
>
>
>
> If I remove line 20, then it would in runtime in line 22 (when "run"
> is invoked for a incoming request).
>
>
> The only solution for it to work in 1.9 is to add ALL the Module/Class
> namespace for ALL the modules/classes:
>
> Rack::Builder.new do
> map "/" do
> puts "[1] MY_VAR = #{::MyRack::MY_VAR}" <----- [1] (line 20)
> run Proc.new { |env|
> puts "[2] MY_VAR = #{::MyRack::MY_VAR}" <-----
> [2] (line 22)
> [ 200, {"Content-Type" => "text/plain"}, ["Yeah"] ]
> }
> end
> end
>
>
> It's VERY important to note that if I use "MyRack::MY_VAR" instead of
> "::MyRack::MY_VAR" then it would *also* fail in Ruby1.9:
>
> `block (2 levels) in core': uninitialized constant
> Rack::Builder::MyRack (NameError)
>
>
> It seems that using instance_eval in Ruby1.9 a class/module is just
> looked for into the class/module executing the instance_eval and
> doesn't look on top of it.
>
>
> Regards.
>
>
> --
> Iñaki Baz Castillo
> <ibc@aliax.net>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb)
2009-09-15 11:59 ` Magnus Holm
@ 2009-09-15 12:46 ` Iñaki Baz Castillo
2009-09-15 16:03 ` Yehuda Katz
0 siblings, 1 reply; 4+ messages in thread
From: Iñaki Baz Castillo @ 2009-09-15 12:46 UTC (permalink / raw)
To: rack-devel
2009/9/15 Magnus Holm <judofyr@gmail.com>:
>
> Also see http://coderrr.wordpress.com/2009/06/02/fixing-constant-lookup-in-dsls-in-ruby-1-9/
Really interesting. So it's a bug in Ruby1.9.
Is it known if it's being addressed by developers?
Thanks a lot.
--
Iñaki Baz Castillo
<ibc@aliax.net>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb)
2009-09-15 12:46 ` Iñaki Baz Castillo
@ 2009-09-15 16:03 ` Yehuda Katz
0 siblings, 0 replies; 4+ messages in thread
From: Yehuda Katz @ 2009-09-15 16:03 UTC (permalink / raw)
To: rack-devel
[-- Attachment #1: Type: text/plain, Size: 657 bytes --]
I wouldn't call it a bug. It's more just a change in the semantics of Ruby.
Matz has said he's thinking about reverting this change at some point in the
future.
-- Yehuda
On Tue, Sep 15, 2009 at 8:46 AM, Iñaki Baz Castillo <ibc@aliax.net> wrote:
>
> 2009/9/15 Magnus Holm <judofyr@gmail.com>:
> >
> > Also see
> http://coderrr.wordpress.com/2009/06/02/fixing-constant-lookup-in-dsls-in-ruby-1-9/
>
> Really interesting. So it's a bug in Ruby1.9.
> Is it known if it's being addressed by developers?
>
> Thanks a lot.
>
> --
> Iñaki Baz Castillo
> <ibc@aliax.net>
>
--
Yehuda Katz
Developer | Engine Yard
(ph) 718.877.1325
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2009-09-15 11:50 Issue using Ruby1.9 (instance_eval in /lib/rack/builder.rb) Iñaki Baz Castillo
2009-09-15 11:59 ` Magnus Holm
2009-09-15 12:46 ` Iñaki Baz Castillo
2009-09-15 16:03 ` Yehuda Katz
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