From 3e57226720d0b8245629cfb2620cf4daa14f15b7 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Sat, 19 Jan 2019 11:34:26 +0900
Subject: [PATCH] Deprecate iterator? method

---
 spec/ruby/core/kernel/iterator_spec.rb | 14 ++++++++------
 vm_eval.c                              | 18 +++++++++++++++---
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/spec/ruby/core/kernel/iterator_spec.rb b/spec/ruby/core/kernel/iterator_spec.rb
index 7fbdade9dc..6ebf49b174 100644
--- a/spec/ruby/core/kernel/iterator_spec.rb
+++ b/spec/ruby/core/kernel/iterator_spec.rb
@@ -1,12 +1,14 @@
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
-describe "Kernel#iterator?" do
-  it "is a private method" do
-    Kernel.should have_private_instance_method(:iterator?)
+ruby_version_is ""..."2.7" do
+  describe "Kernel#iterator?" do
+    it "is a private method" do
+      Kernel.should have_private_instance_method(:iterator?)
+    end
   end
-end
 
-describe "Kernel.iterator?" do
-  it "needs to be reviewed for spec completeness"
+  describe "Kernel.iterator?" do
+    it "needs to be reviewed for spec completeness"
+  end
 end
diff --git a/vm_eval.c b/vm_eval.c
index 0e7047af65..8bc83f4dec 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -2095,7 +2095,6 @@ rb_f_local_variables(void)
 /*
  *  call-seq:
  *     block_given?   -> true or false
- *     iterator?      -> true or false
  *
  *  Returns <code>true</code> if <code>yield</code> would execute a
  *  block in the current context. The <code>iterator?</code> form
@@ -2113,7 +2112,6 @@ rb_f_local_variables(void)
  *     try do "hello" end   #=> "hello"
  */
 
-
 static VALUE
 rb_f_block_given_p(void)
 {
@@ -2129,6 +2127,20 @@ rb_f_block_given_p(void)
     }
 }
 
+/*
+ *  call-seq:
+ *     iterator?      -> true or false
+ *
+ *  Deprecated.  Use block_given? instead.
+ */
+
+static VALUE
+rb_f_iterator_p(void)
+{
+    rb_warning("iterator? is deprecated; use block_given? instead");
+    return rb_f_block_given_p();
+}
+
 VALUE
 rb_current_realfilepath(void)
 {
@@ -2144,7 +2156,7 @@ Init_vm_eval(void)
 {
     rb_define_global_function("eval", rb_f_eval, -1);
     rb_define_global_function("local_variables", rb_f_local_variables, 0);
-    rb_define_global_function("iterator?", rb_f_block_given_p, 0);
+    rb_define_global_function("iterator?", rb_f_iterator_p, 0);
     rb_define_global_function("block_given?", rb_f_block_given_p, 0);
 
     rb_define_global_function("catch", rb_f_catch, -1);
-- 
2.20.1