proc.c: make #lambda private

src/proc.c

@@ -505,5 +505,5 @@ mrb_init_proc(mrb_state *mrb)
   mrb_define_method_raw(mrb, pc, MRB_SYM(call), m);   /* 15.2.17.4.3 */
   mrb_define_method_raw(mrb, pc, MRB_OPSYM(aref), m); /* 15.2.17.4.1 */
 
-  mrb_define_method(mrb, mrb->kernel_module,       "lambda", proc_lambda, MRB_ARGS_NONE()|MRB_ARGS_BLOCK()); /* 15.3.1.3.27 */
+  mrb_define_private_method_id(mrb, mrb->kernel_module, MRB_SYM(lambda), proc_lambda, MRB_ARGS_NONE()|MRB_ARGS_BLOCK()); /* 15.3.1.3.27 */
 }

test/t/kernel.rb

@@ -35,18 +35,7 @@ assert('Kernel.iterator?', '15.3.1.2.5') do
   assert_false Kernel.iterator?
 end
 
-assert('Kernel.lambda', '15.3.1.2.6') do
-  l = Kernel.lambda do
-    true
-  end
-
-  m = Kernel.lambda(&l)
-
-  assert_true l.call
-  assert_equal Proc, l.class
-  assert_true m.call
-  assert_equal Proc, m.class
-end
+# Kernel.lambda is not provided by mruby. '15.3.1.2.6'
 
 assert('Kernel.loop', '15.3.1.2.8') do
   i = 0