Bug #2787: nil.instance_eval pushes nil onto cref
http://redmine.ruby-lang.org/issues/show/2787
e$B5/I<<Te(B: Shugo M.
e$B%9%F!<%?%9e(B: Assigned, e$BM%@hEYe(B: Low
e$BC4Ev<Te(B: Yukihiro M., e$B%+%F%4%je(B: core
ruby -v: ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]
A singleton class definition of nil pushes NilClass onto cref.
It is reasonable because NilClass has nil as the only instance.
However, nil.instance_eval pushes nil onto cref, which means that method
definitions are not permitted in that context.
defiant:ruby$ ruby-trunk -ve ‘class <<nil; def foo; puts “foo” end;
end; nil.foo’
ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]
foo
defiant:ruby$ ruby-trunk -ve ‘nil.instance_eval {|i| def foo; puts
“foo” end }; nil.foo’
ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]
-e:1:in block in <main>': no class/module to add method (TypeError) from -e:1:in instance_eval’
from -e:1:in `’
The behavior is the same in Ruby 1.8.7.
Is it intended or a bug?