update rdoc of dig methods [ci skip]

* array.c (rb_ary_dig), hash.c (rb_hash_dig): [DOC] Update
  comments describing dig methods.  [Fix GH-1103]
* struct.c (rb_struct_dig): [DOC] add rdoc.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52607 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 14 insertions, 0 deletions

diff --git a/struct.c b/struct.c
index d8c781efa6..cebc445a43 100644
--- a/struct.c
+++ b/struct.c
@@ -1126,6 +1126,20 @@ rb_struct_size(VALUE s)
     return LONG2FIX(RSTRUCT_LEN(s));
 }
 
+/*
+ * call-seq:
+ *   struct.dig(key, ...)              -> object
+ *
+ * Extracts the nested struct value specified by the sequence of <i>key</i>
+ * objects.
+ *
+ *   klass = Struct.new(:a)
+ *   o = klass.new(klass.new({b: [1, 2, 3]}))
+ *
+ *   o.dig(:a, :a, :b, 0)              #=> 1
+ *   o.dig(:b, 0)                      #=> nil
+ */
+
 static VALUE
 rb_struct_dig(int argc, VALUE *argv, VALUE self)
 {