enumerator.c: rb_arithmetic_sequence_extract

New public C-API for extracting components of Enumerator::ArithmeticSequence
or Range.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66351 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 21 insertions, 0 deletions

diff --git a/enumerator.c b/enumerator.c
index 615f933778..436541070f 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -2777,6 +2777,27 @@ arith_seq_exclude_end_p(VALUE self)
     return RTEST(arith_seq_exclude_end(self));
 }
 
+int
+rb_arithmetic_sequence_extract(VALUE obj, VALUE *begin, VALUE *end, VALUE *step, int *exclude_end)
+{
+    if (rb_obj_is_kind_of(obj, rb_cArithSeq)) {
+        *begin = arith_seq_begin(obj);
+        *end   = arith_seq_end(obj);
+        *step  = arith_seq_step(obj);
+        *exclude_end = arith_seq_exclude_end_p(obj);
+        return 1;
+    }
+    else if (rb_obj_is_kind_of(obj, rb_cRange)) {
+        *begin = RANGE_BEG(obj);
+        *end   = RANGE_END(obj);
+        *step  = INT2FIX(1);
+        *exclude_end = RTEST(RANGE_EXCL(obj));
+        return 1;
+    }
+
+    return 0;
+}
+
 /*
  * call-seq:
  *   aseq.first -> num or nil