Ruby 1.9.2 compat: add to_str to ColumnDefinition

Right.

Updated the patch not to use to_str nor to_s.

(from [8dab61d146f26c18acdef1fcc57b01612f96440c]) Ruby 1.9.2 compat: Array#* uses to_str instead of to_s to join values since Ruby 1.9.2

[#2959 Ruby 1.9.2 compat: add to_str to ColumnDefinition state:committed]

Signed-off-by: Jeremy Kemper jeremy@bitsweat.net
http://github.com/rails/rails/commit/8dab61d146f26c18acdef1fcc57b01...

I checked on Ruby 1.9.2 and it appears to still use to_s. Did I miss this change?

$ ruby19 -v
ruby 1.9.2dev (2009-08-06) [i386-darwin9.7.0]
$ irb19
>> class Foo; def to_s; 'bar' end end
=> nil
>> [Foo.new, Foo.new] * ' '
=> "bar bar"

Is something redefined in Struct? (ColumnDefinition is a Struct)

$ irb --prompt=simple

RUBY_DESCRIPTION => "ruby 1.9.2dev (2009-07-31 trunk 24341) [i386-darwin9.7.0]" X = Class.new => X [X.new, X.new] * '--' => "#<X:0x2e0f04>--#<X:0x2e0ec8>" Y = Struct.new(:a, :b) => Y [Y.new, Y.new] * '--' => "------" # 3 separators ?? class Y; def to_s; 'hi!'; end; end => nil [Y.new, Y.new] * '--' => "------" class Y; def to_str; 'hola!'; end; end => nil [Y.new, Y.new] * '--' => "hola!--hola!"

bah. Hope this formats correctly.

$ irb --prompt=simple
>> RUBY_DESCRIPTION
=> "ruby 1.9.2dev (2009-07-31 trunk 24341) [i386-darwin9.7.0]"
>> X = Class.new
=> X
>> [X.new, X.new] * '--'
=> "#<X:0x2e0f04>--#<X:0x2e0ec8>"
>> Y = Struct.new(:a, :b)
=> Y
>> [Y.new, Y.new] * '--'
=> "------"
>> class Y; def to_s; 'hi!'; end; end
=> nil
>> [Y.new, Y.new] * '--'
=> "------"
>> class Y; def to_str; 'hola!'; end; end
=> nil
>> [Y.new, Y.new] * '--'
=> "hola!--hola!"

Yes, it's because of Struct#to_a

>> Bar = Struct.new(:a, :b)
=> Bar
>> bars = [Bar.new('1', '2'), Bar.new('3', '4')]
=> [#<struct Bar a="1", b="2">, #<struct Bar a="3", b="4">]
>> bars * '--'
=> "1--2--3--4"
>> class Bar; def to_s; 'foo' end end
=> nil
>> bars * '--'
=> "1--2--3--4"
>> class Bar; undef_method :to_a end
=> Bar
>> bars * '--'
=> "#<struct Bar a=\"1\", b=\"2\">--#<struct Bar a=\"3\", b=\"4\">"
>> class Bar; def to_str; 'foo' end end
=> nil
>> bars * '--'
=> "foo--foo"

To see why, check ary_join_1:

          default:
            tmp = rb_check_string_type(val);
            if (!NIL_P(tmp)) {
                val = tmp;
                goto str_join;
            }
            tmp = rb_check_convert_type(val, T_ARRAY, "Array", "to_a");
            if (!NIL_P(tmp)) {
                obj = val;
                val = tmp;
                goto ary_join;
            }

rb_check_convert_type catches Struct since it's T_DATA, so it's incorrectly treated as joining a recursive array.

I think this is a Ruby bug.

Actually, it's intentional:

commit d32b853e4502e385372e5ae45503290df824518e
Author: matz 
Date:   Fri Jul 3 18:14:33 2009 +0000

    * enum.c (enum_join): add Enumerable#join.
    
    * array.c (ary_join_1): recursive join for Enumerators (and
      objects with #to_a).
    
    * array.c (rb_ary_join): performance tune.
    
    git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@23951 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Oops, I cut and pasted too much.

>> class Bar; undef_method :to_a end
=> Bar
>> bars * '--'
=> "#<struct Bar a=\"1\", b=\"2\">--#<struct Bar a=\"3\", b=\"4\">"

above actually results in "foo--foo" since to_s is defined.

Reported http://redmine.ruby-lang.org/issues/show/1893