Kernel#inspect: improve consistency and do not call #to_s.

* object.c (rb_obj_inspect): Kernel#inspect: do not call #to_s. A class
  can now benefit from the nice default #inspect even if it defines #to_s.
  Also, there is no more unexpected change in #inspect result.
* NEWS: Add note about the change.
* bignum.c, io.c, numeric.c, object.c, proc.c, vm.c (Init_*):
  Adapt internal structures (by aliasing #inspect to #to_s) so they
  don't rely on the removed behavior (#inspect calling overridden #to_s).
* test/ruby/test_object.rb (test_inspect): add tests for Kernel#inspect.
* lib/pp.rb (class PP): do not call #to_s anymore, as #inspect
  no more does (mame).
* test/test_pp.rb (class PPInspectTest): remove related assertion (mame).
  [ruby-core:43238][Feature #6130]
* test/drb/drbtest.rb (DRbCore#teardown, DRbAry#teardown):
  adapt DRb tests with the new change (shirosaki).
  [ruby-core:47182][Bug #6866]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36709 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

12 files changed, 72 insertions, 39 deletions

diff --git a/ChangeLog b/ChangeLog
index 4c94d17917..2608d91ca2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,27 @@
+Wed Aug 15 20:47:49 2012  Benoit Daloze  <eregontp@gmail.com>
+
+	* object.c (rb_obj_inspect): Kernel#inspect: do not call #to_s. A class
+	  can now benefit from the nice default #inspect even if it defines #to_s.
+	  Also, there is no more unexpected change in #inspect result.
+
+	* NEWS: Add note about the change.
+
+	* bignum.c, io.c, numeric.c, object.c, proc.c, vm.c (Init_*):
+	  Adapt internal structures (by aliasing #inspect to #to_s) so they
+	  don't rely on the removed behavior (#inspect calling overridden #to_s).
+
+	* test/ruby/test_object.rb (test_inspect): add tests for Kernel#inspect.
+
+	* lib/pp.rb (class PP): do not call #to_s anymore, as #inspect
+	  no more does (mame).
+
+	* test/test_pp.rb (class PPInspectTest): remove related assertion (mame).
+	  [ruby-core:43238][Feature #6130]
+
+	* test/drb/drbtest.rb (DRbCore#teardown, DRbAry#teardown):
+	  adapt DRb tests with the new change (shirosaki).
+	  [ruby-core:47182][Bug #6866]
+
 Wed Aug 15 18:05:37 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* lib/test/unit.rb (Test::Unit::Runner#failed): need to delete the
diff --git a/NEWS b/NEWS
index ce1dc8be9f..5715b552b4 100644
--- a/NEWS
+++ b/NEWS
@@ -46,6 +46,8 @@ with all sufficient information, see the ChangeLog file.
       * __callee__ has returned to the original behavior, and now
         returns the called name but not the original name in an
         aliased method.
+      * Kernel#inspect does not call #to_s anymore
+        (it used to call redefined #to_s).
 
   * LoadError
     * added method:
diff --git a/bignum.c b/bignum.c
index 3394825ce8..fc713a00cd 100644
--- a/bignum.c
+++ b/bignum.c
@@ -3835,6 +3835,7 @@ Init_Bignum(void)
     rb_cBignum = rb_define_class("Bignum", rb_cInteger);
 
     rb_define_method(rb_cBignum, "to_s", rb_big_to_s, -1);
+    rb_define_alias(rb_cBignum, "inspect", "to_s");
     rb_define_method(rb_cBignum, "coerce", rb_big_coerce, 1);
     rb_define_method(rb_cBignum, "-@", rb_big_uminus, 0);
     rb_define_method(rb_cBignum, "+", rb_big_plus, 1);
diff --git a/io.c b/io.c
index 52eb49574b..b1a38cc707 100644
--- a/io.c
+++ b/io.c
@@ -11505,6 +11505,7 @@ Init_IO(void)
     rb_define_method(rb_cARGF, "initialize", argf_initialize, -2);
     rb_define_method(rb_cARGF, "initialize_copy", argf_initialize_copy, 1);
     rb_define_method(rb_cARGF, "to_s", argf_to_s, 0);
+    rb_define_alias(rb_cARGF, "inspect", "to_s");
     rb_define_method(rb_cARGF, "argv", argf_argv, 0);
 
     rb_define_method(rb_cARGF, "fileno", argf_fileno, 0);
diff --git a/lib/pp.rb b/lib/pp.rb
index 94269abe65..6e0c797d2e 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -265,8 +265,7 @@ class PP < PrettyPrint
   module ObjectMixin
     # 1. specific pretty_print
     # 2. specific inspect
-    # 3. specific to_s
-    # 4. generic pretty_print
+    # 3. generic pretty_print
 
     # A default pretty printing method for general objects.
     # It calls #pretty_print_instance_variables to list instance variables.
@@ -283,18 +282,10 @@ class PP < PrettyPrint
         inspect_method = method_method.call(:inspect)
       rescue NameError
       end
-      begin
-        to_s_method = method_method.call(:to_s)
-      rescue NameError
-      end
       if inspect_method && /\(Kernel\)#/ !~ inspect_method.inspect
         q.text self.inspect
       elsif !inspect_method && self.respond_to?(:inspect)
         q.text self.inspect
-      elsif to_s_method && /\(Kernel\)#/ !~ to_s_method.inspect
-        q.text self.to_s
-      elsif !to_s_method && self.respond_to?(:to_s)
-        q.text self.to_s
       else
         q.pp_object(self)
       end
diff --git a/numeric.c b/numeric.c
index 73626e1c05..5ac5449238 100644
--- a/numeric.c
+++ b/numeric.c
@@ -3660,6 +3660,7 @@ Init_Numeric(void)
     rb_cFixnum = rb_define_class("Fixnum", rb_cInteger);
 
     rb_define_method(rb_cFixnum, "to_s", fix_to_s, -1);
+    rb_define_alias(rb_cFixnum, "inspect", "to_s");
 
     rb_define_method(rb_cFixnum, "-@", fix_uminus, 0);
     rb_define_method(rb_cFixnum, "+", fix_plus, 1);
@@ -3720,6 +3721,7 @@ Init_Numeric(void)
     rb_define_const(rb_cFloat, "NAN", DBL2NUM(NAN));
 
     rb_define_method(rb_cFloat, "to_s", flo_to_s, 0);
+    rb_define_alias(rb_cFloat, "inspect", "to_s");
     rb_define_method(rb_cFloat, "coerce", flo_coerce, 1);
     rb_define_method(rb_cFloat, "-@", flo_uminus, 0);
     rb_define_method(rb_cFloat, "+", flo_plus, 1);
diff --git a/object.c b/object.c
index 1e005e53af..b7e1b58c81 100644
--- a/object.c
+++ b/object.c
@@ -450,11 +450,8 @@ inspect_obj(VALUE obj, VALUE str, int recur)
  *     obj.inspect   -> string
  *
  * Returns a string containing a human-readable representation of <i>obj</i>.
- * By default, if the <i>obj</i> has instance variables, show the class name
- * and instance variable details which is the list of the name and the result
- * of <i>inspect</i> method for each instance variable.
- * Otherwise uses the <i>to_s</i> method to generate the string.
- * If the <i>to_s</i> method is overridden, uses it.
+ * By default, show the class name and the list of the instance variables and
+ * their values (by calling #inspect on each of them).
  * User defined classes should override this method to make better
  * representation of <i>obj</i>.  When overriding this method, it should
  * return a string whose encoding is compatible with the default external
@@ -479,35 +476,21 @@ inspect_obj(VALUE obj, VALUE str, int recur)
  *         "baz"
  *       end
  *     end
- *     Baz.new.inspect                  #=> "baz"
+ *     Baz.new.inspect                  #=> "#<Baz:0x0300c868>"
  */
 
 static VALUE
 rb_obj_inspect(VALUE obj)
 {
-    if (RB_TYPE_P(obj, T_OBJECT) && rb_obj_basic_to_s_p(obj)) {
-        int has_ivar = 0;
-        VALUE *ptr = ROBJECT_IVPTR(obj);
-        long len = ROBJECT_NUMIV(obj);
-        long i;
-
-        for (i = 0; i < len; i++) {
-            if (ptr[i] != Qundef) {
-                has_ivar = 1;
-                break;
-            }
-        }
-
-        if (has_ivar) {
-            VALUE str;
-            const char *c = rb_obj_classname(obj);
+    if (rb_ivar_count(obj) > 0) {
+	VALUE str;
+	const char *c = rb_obj_classname(obj);
 
-            str = rb_sprintf("-<%s:%p", c, (void*)obj);
-            return rb_exec_recursive(inspect_obj, obj, str);
-        }
+	str = rb_sprintf("-<%s:%p", c, (void*)obj);
+	return rb_exec_recursive(inspect_obj, obj, str);
+    } else {
 	return rb_any_to_s(obj);
     }
-    return rb_funcall(obj, rb_intern("to_s"), 0, 0);
 }
 
 static VALUE
@@ -2951,6 +2934,7 @@ Init_Object(void)
     rb_define_method(rb_cModule, ">=", rb_mod_ge, 1);
     rb_define_method(rb_cModule, "initialize_copy", rb_mod_init_copy, 1); /* in class.c */
     rb_define_method(rb_cModule, "to_s", rb_mod_to_s, 0);
+    rb_define_alias(rb_cModule, "inspect", "to_s");
     rb_define_method(rb_cModule, "included_modules", rb_mod_included_modules, 0); /* in class.c */
     rb_define_method(rb_cModule, "include?", rb_mod_include_p, 1); /* in class.c */
     rb_define_method(rb_cModule, "name", rb_mod_name, 0);  /* in variable.c */
@@ -3003,6 +2987,7 @@ Init_Object(void)
 
     rb_cTrueClass = rb_define_class("TrueClass", rb_cObject);
     rb_define_method(rb_cTrueClass, "to_s", true_to_s, 0);
+    rb_define_alias(rb_cTrueClass, "inspect", "to_s");
     rb_define_method(rb_cTrueClass, "&", true_and, 1);
     rb_define_method(rb_cTrueClass, "|", true_or, 1);
     rb_define_method(rb_cTrueClass, "^", true_xor, 1);
@@ -3015,6 +3000,7 @@ Init_Object(void)
 
     rb_cFalseClass = rb_define_class("FalseClass", rb_cObject);
     rb_define_method(rb_cFalseClass, "to_s", false_to_s, 0);
+    rb_define_alias(rb_cFalseClass, "inspect", "to_s");
     rb_define_method(rb_cFalseClass, "&", false_and, 1);
     rb_define_method(rb_cFalseClass, "|", false_or, 1);
     rb_define_method(rb_cFalseClass, "^", false_xor, 1);
diff --git a/proc.c b/proc.c
index 6ccb888bd7..9ed6dbb2e7 100644
--- a/proc.c
+++ b/proc.c
@@ -2217,6 +2217,7 @@ Init_Proc(void)
     rb_define_method(rb_cProc, "eql?", proc_eq, 1);
     rb_define_method(rb_cProc, "hash", proc_hash, 0);
     rb_define_method(rb_cProc, "to_s", proc_to_s, 0);
+    rb_define_alias(rb_cProc, "inspect", "to_s");
     rb_define_method(rb_cProc, "lambda?", rb_proc_lambda_p, 0);
     rb_define_method(rb_cProc, "binding", proc_binding, 0);
     rb_define_method(rb_cProc, "curry", proc_curry, -1);
diff --git a/test/drb/drbtest.rb b/test/drb/drbtest.rb
index 1cb8b1f95b..d0156fd9e4 100644
--- a/test/drb/drbtest.rb
+++ b/test/drb/drbtest.rb
@@ -73,7 +73,7 @@ module DRbCore
   def teardown
     @ext.stop_service if defined?(@ext) && @ext
     DRbService.manager.unregist(@service_name)
-    while (@there.inspect rescue nil)
+    while (@there.to_s rescue nil)
       # nop
     end
     signal = /mswin|mingw/ =~ RUBY_PLATFORM ? :INT : :TERM
@@ -294,7 +294,7 @@ module DRbAry
   def teardown
     @ext.stop_service if defined?(@ext) && @ext
     DRbService.manager.unregist(@service_name)
-    while (@there.inspect rescue nil)
+    while (@there.to_s rescue nil)
       # nop
     end
     signal = /mswin|mingw/ =~ RUBY_PLATFORM ? :INT : :TERM
diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 70dcd04201..61482f7c1a 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -690,6 +690,31 @@ class TestObject < Test::Unit::TestCase
     assert_equal(true, s.tainted?)
   end
 
+  def test_inspect
+    x = Object.new
+    assert_match(/\A#<Object:0x\h+>\z/, x.inspect)
+
+    x.instance_variable_set(:@ivar, :value)
+    assert_match(/\A#<Object:0x\h+ @ivar=:value>\z/, x.inspect)
+
+    x = Object.new
+    x.instance_variable_set(:@recur, x)
+    assert_match(/\A#<Object:0x\h+ @recur=#<Object:0x\h+ \.\.\.>>\z/, x.inspect)
+
+    x = Object.new
+    x.instance_variable_set(:@foo, "value")
+    x.instance_variable_set(:@bar, 42)
+    assert_match(/\A#<Object:0x\h+ (?:@foo="value", @bar=42|@bar=42, @foo="value")>\z/, x.inspect)
+
+    # #inspect does not call #to_s anymore
+    feature6130 = '[ruby-core:43238]'
+    x = Object.new
+    def x.to_s
+      "to_s"
+    end
+    assert_match(/\A#<Object:0x\h+>\z/, x.inspect, feature6130)
+  end
+
   def test_exec_recursive
     Thread.current[:__recursive_key__] = nil
     a = [[]]
diff --git a/test/test_pp.rb b/test/test_pp.rb
index fe65287d88..acd3e835b9 100644
--- a/test/test_pp.rb
+++ b/test/test_pp.rb
@@ -118,7 +118,6 @@ class PPInspectTest < Test::Unit::TestCase
     def a.to_s() "aaa" end
     result = PP.pp(a, '')
     assert_equal("#{a.inspect}\n", result)
-    assert_equal("aaa\n", result)
   end
 end
 
diff --git a/vm.c b/vm.c
index 30d0f8a7bd..80dd512ae1 100644
--- a/vm.c
+++ b/vm.c
@@ -2229,6 +2229,7 @@ Init_top_self(void)
 
     vm->top_self = rb_obj_alloc(rb_cObject);
     rb_define_singleton_method(rb_vm_top_self(), "to_s", main_to_s, 0);
+    rb_define_alias(rb_singleton_class(rb_vm_top_self()), "inspect", "to_s");
 
     /* initialize mark object array */
     vm->mark_object_ary = rb_ary_tmp_new(1);