Merge pull request #2091 from take-cheeze/struct_len

Implement Struct#size and Struct#length .

mrbgems/mruby-struct/src/struct.c

@@ -779,6 +779,19 @@ mrb_struct_eql(mrb_state *mrb, mrb_value s)
   return mrb_bool_value(eql_p);
 }
 
+/*
+ * call-seq:
+ *    struct.length   -> Fixnum
+ *    struct.size     -> Fixnum
+ *
+ * Returns number of struct members.
+ */
+static mrb_value
+mrb_struct_len(mrb_state *mrb, mrb_value self)
+{
+  return mrb_fixnum_value(RSTRUCT_LEN(self));
+}
+
 /*
  *  A <code>Struct</code> is a convenient way to bundle a number of
  *  attributes together, using accessor methods, without having to write
@@ -811,6 +824,9 @@ mrb_mruby_struct_gem_init(mrb_state* mrb)
   mrb_define_method(mrb, st,       "inspect",         mrb_struct_inspect,     MRB_ARGS_NONE()); /* 15.2.18.4.10(x)  */
   mrb_define_alias(mrb, st,        "to_s", "inspect");                                      /* 15.2.18.4.11(x)  */
   mrb_define_method(mrb, st,       "eql?",            mrb_struct_eql,         MRB_ARGS_REQ(1)); /* 15.2.18.4.12(x)  */
+
+  mrb_define_method(mrb, st,        "size",           mrb_struct_len,         MRB_ARGS_NONE());
+  mrb_define_method(mrb, st,        "length",         mrb_struct_len,         MRB_ARGS_NONE());
 }
 
 void

mrbgems/mruby-struct/test/struct.rb

@@ -107,4 +107,10 @@ if Object.const_defined?(:Struct)
     cc = c.new(1,2,3,4,5)
     assert_equal "#<struct #{c.inspect} m1=1, m2=2, m3=3, m4=4, m5=5>", cc.inspect
   end
+
+  assert('Struct#length, Struct#size') do
+    s = Struct.new(:f1, :f2).new(0, 1)
+    assert_equal 2, s.size
+    assert_equal 2, s.length
+  end
 end