From: Yusuke ENDOH Date: 2008-01-11T23:13:44+09:00 Subject: Re: singleton-of-singleton is Class in 1.9.0 Hi, 2008/1/3, David A. Black : > Hi -- > > On Wed, 2 Jan 2008, Sylvain Joyeux wrote: > > > In 1.9.0, the singleton of a singleton is Class, while in 1.8 it was a > > singleton itself (see below). Is that an intended behaviour just to > > make singletons slightly different than real classes, or is it a bug ? > > > > [~]% irb1.9 > >>> obj = Object.new > > => # > >>> sing = class << obj; self end > > => #> > >>> sing_of_sing = class << sing; self end > > => Class > > > > [~]% irb > >>> obj = Object.new > > => # > >>> sing = class << obj; self end > > => #> > >>> sing_of_sing = class << sing; self end > > => #>> > > I would think it must be a bug. It makes it impossible to add class > methods of a singleton class, which would be an odd limitation. (Maybe > not the most frequent use case, but even so.) I think so, too. Looks like this change was made at the revision 8068, but I cannot understand the rationale from the commit log. $ svn -r8068 log ------------------------------------------------------------------------ r8068 | matz | 2005-03-04 15:47:45 +0900 (Fri, 04 Mar 2005) | 149 lines * array.c: replace rb_protect_inspect() and rb_inspecting_p() by rb_exec_recursive() in eval.c. * eval.c (rb_exec_recursive): new function. * array.c (rb_ary_join): use rb_exec_recursive(). * array.c (rb_ary_inspect, rb_ary_hash): ditto. * file.c (rb_file_join): ditto. * hash.c (rb_hash_inspect, rb_hash_to_s, rb_hash_hash): ditto. * io.c (rb_io_puts): ditto. * object.c (rb_obj_inspect): ditto * struct.c (rb_struct_inspect): ditto. * lib/set.rb (SortedSet::setup): a hack to shut up warning. [ruby-talk:132866] * lib/time.rb (Time::strptime): add new function. inspired by [ruby-talk:132815]. * lib/parsedate.rb (ParseDate::strptime): ditto. * regparse.c: move st_*_strend() functions from st.c. fixed some potential memory leaks. * exception error messages updated. [ruby-core:04497] * ext/socket/socket.c (Init_socket): add bunch of Socket constants. Patch from Sam Roberts . [ruby-core:04409] * array.c (rb_ary_s_create): no need for negative argc check. [ruby-core:04463] * array.c (rb_ary_unshift_m): ditto. * lib/xmlrpc/parser.rb (XMLRPC::FaultException): make it subclass of StandardError class, not Exception class. [ruby-core:04429] * parse.y (fcall_gen): lvar(arg) will be evaluated as lvar.call(arg) when lvar is a defined local variable. [new] * object.c (rb_class_initialize): call inherited method before calling initializing block. * eval.c (rb_thread_start_1): initialize newly pushed frame. * lib/open3.rb (Open3::popen3): $? should not be EXIT_FAILURE. fixed: [ruby-core:04444] * eval.c (is_defined): NODE_IASGN is an assignment. * ext/readline/readline.c (Readline.readline): use rl_outstream and rl_instream. [ruby-dev:25699] * ext/etc/etc.c (Init_etc): sGroup needs HAVE_ST_GR_PASSWD check [ruby-dev:25675] * misc/ruby-mode.el: [ruby-core:04415] * lib/rdoc/generators/html_generator.rb: [ruby-core:04412] * lib/rdoc/generators/ri_generator.rb: ditto. * struct.c (make_struct): fixed: [ruby-core:04402] * ext/curses/curses.c (window_color_set): [ruby-core:04393] * ext/socket/socket.c (Init_socket): SO_REUSEPORT added. [ruby-talk:130092] * object.c: [ruby-doc:818] * parse.y (open_args): fix too verbose warnings for the space before argument parentheses. [ruby-dev:25492] * parse.y (parser_yylex): ditto. * parse.y (parser_yylex): the first expression in the parentheses should not be a command. [ruby-dev:25492] * lib/irb/context.rb (IRB::Context::initialize): [ruby-core:04330] * object.c (Init_Object): remove Object#type. [ruby-core:04335] * st.c (st_foreach): report success/failure by return value. [ruby-Bugs-1396] * parse.y: forgot to initialize parser struct. [ruby-dev:25492] * parse.y (parser_yylex): no tLABEL on EXPR_BEG. [ruby-talk:127711] * document updates - [ruby-core:04296], [ruby-core:04301], [ruby-core:04302], [ruby-core:04307] * dir.c (rb_push_glob): should work for NUL delimited patterns. * dir.c (rb_glob2): should aware of offset in the pattern. * string.c (rb_str_new4): should propagate taintedness. * env.h: rename member names in struct FRAME; last_func -> callee, orig_func -> this_func, last_class -> this_class. * struct.c (rb_struct_set): use original method name, not callee name, to retrieve member slot. [ruby-core:04268] * time.c (time_strftime): protect from format modification from GC finalizers. * object.c (Init_Object): remove rb_obj_id_obsolete() * eval.c (rb_mod_define_method): incomplete subclass check. [ruby-dev:25464] * gc.c (rb_data_object_alloc): klass may be NULL. [ruby-list:40498] * bignum.c (rb_big_rand): should return positive random number. [ruby-dev:25401] * bignum.c (rb_big_rand): do not use rb_big_modulo to generate random bignums. [ruby-dev:25396] * variable.c (rb_autoload): [ruby-dev:25373] * eval.c (svalue_to_avalue): [ruby-dev:25366] * string.c (rb_str_justify): [ruby-dev:25367] * io.c (rb_f_select): [ruby-dev:25312] * ext/socket/socket.c (sock_s_getservbyport): [ruby-talk:124072] * struct.c (make_struct): [ruby-dev:25249] * dir.c (dir_open_dir): new function. [ruby-dev:25242] * io.c (rb_f_open): add type check for return value from to_open. * lib/pstore.rb (PStore#transaction): Use the empty content when a file is not found. [ruby-dev:24561] ------------------------------------------------------------------------ -- Yusuke ENDOH