mruby-string-ext: add unary +/- for strings to freeze/unfreeze
MODIFY
mrbgems/mruby-string-ext/src/string.c
mrbgems/mruby-string-ext/src/string.c
@@ -1243,6 +1243,45 @@ mrb_str_lines(mrb_state *mrb, mrb_value self)
return result;
}
+/*
+ * call-seq:
+ * +string -> new_string or self
+ *
+ * Returns +self+ if +self+ is not frozen.
+ *
+ * Otherwise returns <tt>self.dup</tt>, which is not frozen.
+ */
+static mrb_value
+mrb_str_uplus(mrb_state *mrb, mrb_value str)
+{
+ if (mrb_frozen_p(mrb_obj_ptr(str))) {
+ return mrb_str_dup(mrb, str);
+ }
+ else {
+ return str;
+ }
+}
+
+/*
+ * call-seq:
+ * -string -> frozen_string
+ *
+ * Returns a frozen, possibly pre-existing copy of the string.
+ *
+ * The returned \String will be deduplicated as long as it does not have
+ * any instance variables set on it and is not a String subclass.
+ *
+ * String#dedup is an alias for String#-@.
+ */
+static mrb_value
+mrb_str_uminus(mrb_state *mrb, mrb_value str)
+{
+ if (mrb_frozen_p(mrb_obj_ptr(str))) {
+ return str;
+ }
+ return mrb_obj_freeze(mrb, mrb_str_dup(mrb, str));
+}
+
void
mrb_mruby_string_ext_gem_init(mrb_state* mrb)
{
@@ -1278,6 +1317,8 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb)
mrb_define_method(mrb, s, "delete_suffix", mrb_str_del_suffix, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "casecmp", mrb_str_casecmp, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "casecmp?", mrb_str_casecmp_p, MRB_ARGS_REQ(1));
+ mrb_define_method(mrb, s, "+@", mrb_str_uplus, MRB_ARGS_REQ(1));
+ mrb_define_method(mrb, s, "-@", mrb_str_uminus, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "__lines", mrb_str_lines, MRB_ARGS_NONE());

MODIFY
mrbgems/mruby-string-ext/test/string.rb
mrbgems/mruby-string-ext/test/string.rb
+# coding: utf-8
##
# String(Ext) Test
@@ -712,3 +713,17 @@ assert('String#delete_suffix') do
assert_equal "he", "hello".delete_suffix!("llo")
assert_nil "hello".delete_suffix!("he")
end
+
+assert('String#+@') do
+ a = +"abc"
+ assert_false(a.frozen?)
+ a = +(a.freeze)
+ assert_false(a.frozen?)
+end
+
+assert('String#-@') do
+ a = -"abc"
+ assert_true(a.frozen?)
+ a = -(a.freeze)
+ assert_true(a.frozen?)
+end

mruby-string-ext: add unary +/- for strings to freeze/unfreeze