Asp Forum - Quarks - comp.lang.ruby

Trans

7/28/2007 4:22:00 PM

Why?

class X; end

X.methods(false)
=> []

But...

X.public_methods(false)
=> ["allocate", "superclass", "new"]

X.private_methods(false)
=> ["initialize", "initialize_copy", "inherited"]

T.

9 Answers

John Joyce

7/28/2007 4:42:00 PM

On Jul 28, 2007, at 11:21 AM, Trans wrote:

> Why?
>
> class X; end
>
> X.methods(false)
> => []
>
> But...
>
> X.public_methods(false)
> => ["allocate", "superclass", "new"]
>
> X.private_methods(false)
> => ["initialize", "initialize_copy", "inherited"]
>
> T.
>
>
Inheritance.
Inherits from Object

Trans

7/28/2007 5:29:00 PM

On Jul 28, 9:41 am, John Joyce <dangerwillrobinsondan...@gmail.com>
wrote:
>
> Inheritance.
> Inherits from Object

But the (false) parameter is supposed to limit it to just the class,
no ancestors. And it does mostly. But "mostly" is what doesn't make
sense. If you use (true) instead you get:

X.public_methods(true)
=> ["inspect", "private_class_method", "const_missing", "clone",
"method", "public_methods", "public_instance_methods",
"instance_variable_defined?", "method_defined?", "superclass",
"equal?", "freeze", "included_modules", "const_get", "methods",
"respond_to?", "module_eval", "class_variables", "dup",
"protected_instance_methods", "instance_variables",
"public_method_defined?", "__id__", "eql?", "object_id", "const_set",
"id", "singleton_methods", "send", "class_eval", "taint", "frozen?",
"instance_variable_get", "include?", "private_instance_methods",
"__send__", "instance_of?", "private_method_defined?", "to_a", "name",
"autoload", "type", "new", "<", "protected_methods", "instance_eval",
"<=>", "display", "==", ">", "===", "instance_method",
"instance_variable_set", "kind_of?", "extend",
"protected_method_defined?", "const_defined?", ">=", "ancestors",
"to_s", "<=", "public_class_method", "allocate", "hash", "class",
"instance_methods", "tainted?", "=~", "private_methods",
"class_variable_defined?", "nil?", "untaint", "constants", "is_a?",
"autoload?"]

X.private_methods(true)
=> ["select", "global_variables", "attr", "warn", "initialize",
"readline", "singleton_method_added", "gsub", "exit!", "public",
"method_missing", "method_added", "alias_method", "abort", "exec",
"print", "remove_instance_variable", "chomp!", "load", "eval",
"srand", "proc", "untrace_var", "Integer", "local_variables",
"attr_reader", "readlines", "singleton_method_removed", "inherited",
"raise", "chop", "protected", "getc", "define_method",
"method_removed", "system", "at_exit", "require", "putc", "test",
"set_trace_func", "lambda", "rand", "attr_writer", "Float",
"remove_class_variable", "initialize_copy", "p",
"singleton_method_undefined", "chomp", "fail", "syscall", "callcc",
"sub!", "private", "method_undefined", "iterator?", "catch", "sleep",
"puts", "`", "String", "attr_accessor", "sprintf", "remove_method",
"class_variable_get", "included", "split", "caller", "irb_binding",
"gsub!", "open", "block_given?", "throw", "remove_const", "gets",
"trap", "sub", "loop", "include", "Array", "fork", "undef_method",
"class_variable_set", "extended", "format", "exit", "printf", "chop!",
"trace_var", "binding", "scan"]

T.

John Joyce

7/28/2007 7:27:00 PM

On Jul 28, 2007, at 12:28 PM, Trans wrote:

>
>
> On Jul 28, 9:41 am, John Joyce <dangerwillrobinsondan...@gmail.com>
> wrote:
>>
>> Inheritance.
>> Inherits from Object
>
> But the (false) parameter is supposed to limit it to just the class,
> no ancestors. And it does mostly. But "mostly" is what doesn't make
> sense. If you use (true) instead you get:
>
Check the docs again
ri methods

--------------------------------------------------------- Object#methods
obj.methods => array
------------------------------------------------------------------------
Returns a list of the names of methods publicly accessible in
_obj_. This will include all the methods accessible in _obj_'s
ancestors.

ri public_methods

-------------------------------------------------- Object#public_methods
obj.public_methods(all=true) => array
------------------------------------------------------------------------
Returns the list of public methods accessible to _obj_. If the
_all_ parameter is set to +false+, only those methods in the
receiver will be listed.

So it matters what it means that "methods in the receiver" will be
listed.
some methods are built in to every object.
You can make them private if you need to but then what good would
they be?
Sending .methods(false) will just give you an empty array. Not useful.

Somethings to read about in ri :
Object
Kernel
Singleton

These classes are pretty important to understanding some of these
aspects of the Ruby object model and inheritance.
Read those carefully and it will be a little more clear.

Joel VanderWerf

7/28/2007 8:21:00 PM

John Joyce wrote:
> ri methods
>
> --------------------------------------------------------- Object#methods
> obj.methods => array
> ------------------------------------------------------------------------
> Returns a list of the names of methods publicly accessible in
> _obj_. This will include all the methods accessible in _obj_'s
> ancestors.

Unfortunately that doesn't tell us that it takes an optional argument,
and that if the argument is false, the method returns the result of
obj.singleton_methods(false), which is just the singleton methods
defined on the object.

Looks like a doc bug....

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

Robert Dober

7/28/2007 8:32:00 PM

On 7/28/07, Trans <transfire@gmail.com> wrote:
> Why?
>
> class X; end
>
> X.methods(false)
> => []
>
> But...
>
> X.public_methods(false)
> => ["allocate", "superclass", "new"]
>
> X.private_methods(false)
> => ["initialize", "initialize_copy", "inherited"]
>
> T.
>
>
>

irb(main):001:0> class X;end
=> nil
irb(main):002:0> x=X.new
=> #<X:0xb7d7c21c>
irb(main):003:0> x.methods false
=> []
irb(main):004:0> x.public_methods false
=> []
irb(main):005:0> x.private_methods false
=> []

seems quite ok.
The result of
X.public_methods false and
X.private_methods false
seems correct
but why the hack ;) is
X.methods false
empty????

Robert
--
[...] as simple as possible, but no simpler.
-- Attributed to Albert Einstein

Robert Dober

7/28/2007 8:34:00 PM

On 7/28/07, Robert Dober <robert.dober@gmail.com> wrote:
> On 7/28/07, Trans <transfire@gmail.com> wrote:
> > Why?
> >
> > class X; end
> >
> > X.methods(false)
> > => []
> >
> > But...
> >
> > X.public_methods(false)
> > => ["allocate", "superclass", "new"]
> >
> > X.private_methods(false)
> > => ["initialize", "initialize_copy", "inherited"]
> >
> > T.
> >
> >
> >
>
> irb(main):001:0> class X;end
> => nil
> irb(main):002:0> x=X.new
> => #<X:0xb7d7c21c>
> irb(main):003:0> x.methods false
> => []
> irb(main):004:0> x.public_methods false
> => []
> irb(main):005:0> x.private_methods false
> => []
>
> seems quite ok.

The following is the *uppercase* X, sorry very bad naming of my part :(.
> The result of
> X.public_methods false and
> X.private_methods false
> seems correct
> but why the hack ;) is
> X.methods false
> empty????
>
> Robert
> --
> [...] as simple as possible, but no simpler.
> -- Attributed to Albert Einstein
>

--
[...] as simple as possible, but no simpler.
-- Attributed to Albert Einstein

Nobuyoshi Nakada

7/28/2007 9:18:00 PM

Hi,

At Sun, 29 Jul 2007 01:21:46 +0900,
Trans wrote in [ruby-talk:262287]:
> Why?

Maybe a bug.

Index: class.c
===================================================================
--- class.c (revision 12852)
+++ class.c (working copy)
@@ -600,9 +600,18 @@ class_instance_method_list(int argc, VAL

list = st_init_numtable();
- for (; mod; mod = RCLASS(mod)->super) {
+ if (mod) {
st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
- if (BUILTIN_TYPE(mod) == T_ICLASS) continue;
- if (FL_TEST(mod, FL_SINGLETON)) continue;
- if (!recur) break;
+ if (recur) {
+ while ((mod = RCLASS(mod)->super) != 0) {
+ st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
+ }
+ }
+#define HIDDEN_CLASS_P(mod) ((BUILTIN_TYPE(mod) == T_ICLASS) || + (FL_TEST(mod, FL_SINGLETON)))
+ else if (HIDDEN_CLASS_P(mod)) {
+ while ((mod = RCLASS(mod)->super) != 0 && HIDDEN_CLASS_P(mod)) {
+ st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
+ }
+ }
}
ary = rb_ary_new();

--
Nobu Nakada

Trans

7/29/2007 10:55:00 AM

On Jul 28, 2:17 pm, Nobuyoshi Nakada <n...@ruby-lang.org> wrote:
> Hi,
>
> At Sun, 29 Jul 2007 01:21:46 +0900,
> Trans wrote in [ruby-talk:262287]:
>
> > Why?
>
> Maybe a bug.
>
> Index: class.c
> ===================================================================
> --- class.c (revision 12852)
> +++ class.c (working copy)
> @@ -600,9 +600,18 @@ class_instance_method_list(int argc, VAL
>
> list = st_init_numtable();
> - for (; mod; mod = RCLASS(mod)->super) {
> + if (mod) {
> st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
> - if (BUILTIN_TYPE(mod) == T_ICLASS) continue;
> - if (FL_TEST(mod, FL_SINGLETON)) continue;
> - if (!recur) break;
> + if (recur) {
> + while ((mod = RCLASS(mod)->super) != 0) {
> + st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
> + }
> + }
> +#define HIDDEN_CLASS_P(mod) ((BUILTIN_TYPE(mod) == T_ICLASS) || > + (FL_TEST(mod, FL_SINGLETON)))
> + else if (HIDDEN_CLASS_P(mod)) {
> + while ((mod = RCLASS(mod)->super) != 0 && HIDDEN_CLASS_P(mod)) {
> + st_foreach(RCLASS(mod)->m_tbl, method_entry, (st_data_t)list);
> + }
> + }
> }
> ary = rb_ary_new();

Thanks Nobu. Though that code seems kind of odd too. Does 'recur'
refer to the ancestors flag? If so, how does the HIDDEN_CLASS_P (he
he, another name for singleton) exclude the ancestors?

T.

Nobuyoshi Nakada

7/29/2007 12:51:00 PM

Hi,

At Sun, 29 Jul 2007 19:54:58 +0900,
Trans wrote in [ruby-talk:262375]:
> Thanks Nobu. Though that code seems kind of odd too. Does 'recur'
> refer to the ancestors flag? If so, how does the HIDDEN_CLASS_P (he
> he, another name for singleton) exclude the ancestors?

If recur is true, all ancestors are included. If false, search
before an ordinary class. Still I'm not sure about this
behavior, singleton methods include methods from modules,
though.

--
Nobu Nakada

comp.lang.ruby

Quarks

Trans

John Joyce

Trans

John Joyce

Joel VanderWerf

Robert Dober

Robert Dober

Nobuyoshi Nakada

Trans

Nobuyoshi Nakada

x Login to ForumsZone