3 files changed, 69 insertions, 0 deletions
diff --git a/ext/-test-/arith_seq/extract/extconf.rb b/ext/-test-/arith_seq/extract/extconf.rb
new file mode 100644
index 0000000000..9c368bf50e
--- /dev/null
+++ b/ext/-test-/arith_seq/extract/extconf.rb
@@ -0,0 +1,2 @@
+# frozen_string_literal: false
+create_makefile("-test-/arith_seq/extract")
diff --git a/ext/-test-/arith_seq/extract/extract.c b/ext/-test-/arith_seq/extract/extract.c
new file mode 100644
index 0000000000..602afa7ca1
--- /dev/null
+++ b/ext/-test-/arith_seq/extract/extract.c
@@ -0,0 +1,27 @@
+#include "ruby/ruby.h"
+
+static VALUE
+arith_seq_s_extract(VALUE mod, VALUE obj)
+{
+  rb_arithmetic_sequence_components_t x;
+  VALUE ret;
+  int f, r;
+
+  r = rb_arithmetic_sequence_extract(obj, &x);
+
+  ret = rb_ary_new2(5);
+  rb_ary_store(ret, 0, r ? x.begin : Qnil);
+  rb_ary_store(ret, 1, r ? x.end   : Qnil);
+  rb_ary_store(ret, 2, r ? x.step  : Qnil);
+  rb_ary_store(ret, 3, r ? INT2FIX(x.exclude_end) : Qnil);
+  rb_ary_store(ret, 4, INT2FIX(r));
+
+  return ret;
+}
+
+void
+Init_extract(void)
+{
+    VALUE cArithSeq = rb_path2class("Enumerator::ArithmeticSequence");
+    rb_define_singleton_method(cArithSeq, "__extract__", arith_seq_s_extract, 1);
+}
diff --git a/test/-ext-/arith_seq/test_arith_seq_extract.rb b/test/-ext-/arith_seq/test_arith_seq_extract.rb
new file mode 100644
index 0000000000..d64fe6a7b5
--- /dev/null
+++ b/test/-ext-/arith_seq/test_arith_seq_extract.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class Test_ArithSeq < Test::Unit::TestCase
+  def test_extract_with_arith_seq
+    assert_separately([], <<-"end;") #do
+      require '-test-/arith_seq/extract'
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__(1.step(10, 2))
+      assert_equal([1, 10, 2, 0, 1], [b, e, s, f, r])
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__((1..10) % 2)
+      assert_equal([1, 10, 2, 0, 1], [b, e, s, f, r])
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__((1...10) % 2)
+      assert_equal([1, 10, 2, 1, 1], [b, e, s, f, r])
+    end;
+  end
+
+  def test_extract_with_range
+    assert_separately([], <<-"end;") #do
+      require '-test-/arith_seq/extract'
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__(1..10)
+      assert_equal([1, 10, 1, 0, 1], [b, e, s, f, r])
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__(1...10)
+      assert_equal([1, 10, 1, 1, 1],  [b, e, s, f, r])
+    end;
+  end
+
+  def test_extract_with_others
+    assert_separately([], <<-"end;") #do
+      require '-test-/arith_seq/extract'
+
+      b, e, s, f, r = Enumerator::ArithmeticSequence.__extract__(nil)
+      assert_equal([nil, nil, nil, nil, 0], [b, e, s,  f, r])
+    end;
+  end
+end