From 26dc5f76ea3c092ebfce3053234d6900b8d5dc37 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Sat, 21 Mar 2026 14:35:12 +0900
Subject: [PATCH] mruby-regexp: add MatchData#string, #regexp, and #to_s

Co-authored-by: Claude <noreply@anthropic.com>
---
 mrbgems/mruby-regexp/src/regexp.c   | 38 +++++++++++++++++++++++++++++
 mrbgems/mruby-regexp/test/regexp.rb | 16 ++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/mrbgems/mruby-regexp/src/regexp.c b/mrbgems/mruby-regexp/src/regexp.c
index 85e361c6a..4b9e51acd 100644
--- a/mrbgems/mruby-regexp/src/regexp.c
+++ b/mrbgems/mruby-regexp/src/regexp.c
@@ -587,6 +587,41 @@ matchdata_named_captures(mrb_state *mrb, mrb_value self)
   return result;
 }
 
+/*
+ * MatchData#string - the original string (frozen copy)
+ */
+static mrb_value
+matchdata_string(mrb_state *mrb, mrb_value self)
+{
+  mrb_match_data *md = DATA_GET_PTR(mrb, self, &matchdata_type, mrb_match_data);
+  if (!md) return mrb_nil_value();
+  return md->source;
+}
+
+/*
+ * MatchData#regexp - the Regexp used
+ */
+static mrb_value
+matchdata_regexp(mrb_state *mrb, mrb_value self)
+{
+  mrb_match_data *md = DATA_GET_PTR(mrb, self, &matchdata_type, mrb_match_data);
+  if (!md) return mrb_nil_value();
+  return md->regexp;
+}
+
+/*
+ * MatchData#to_s - full match string
+ */
+static mrb_value
+matchdata_to_s(mrb_state *mrb, mrb_value self)
+{
+  mrb_match_data *md = DATA_GET_PTR(mrb, self, &matchdata_type, mrb_match_data);
+  if (!md || md->captures[0] < 0) return mrb_nil_value();
+  int s = md->captures[0];
+  int e = md->captures[1];
+  return mrb_str_substr(mrb, md->source, s, e - s);
+}
+
 /* --- Gem init --- */
 
 void
@@ -634,6 +669,9 @@ mrb_mruby_regexp_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, md, "pre_match", matchdata_pre, MRB_ARGS_NONE());
   mrb_define_method(mrb, md, "post_match", matchdata_post, MRB_ARGS_NONE());
   mrb_define_method(mrb, md, "named_captures", matchdata_named_captures, MRB_ARGS_NONE());
+  mrb_define_method(mrb, md, "string", matchdata_string, MRB_ARGS_NONE());
+  mrb_define_method(mrb, md, "regexp", matchdata_regexp, MRB_ARGS_NONE());
+  mrb_define_method(mrb, md, "to_s", matchdata_to_s, MRB_ARGS_NONE());
 }
 
 void
diff --git a/mrbgems/mruby-regexp/test/regexp.rb b/mrbgems/mruby-regexp/test/regexp.rb
index 3dc5373b3..e5dd7ffd3 100644
--- a/mrbgems/mruby-regexp/test/regexp.rb
+++ b/mrbgems/mruby-regexp/test/regexp.rb
@@ -114,6 +114,22 @@ assert("MatchData#pre_match / #post_match") do
   assert_equal "de", md.post_match
 end
 
+assert("MatchData#string") do
+  md = Regexp.new("bc").match("abcde")
+  assert_equal "abcde", md.string
+end
+
+assert("MatchData#regexp") do
+  re = Regexp.new("bc")
+  md = re.match("abcde")
+  assert_equal re, md.regexp
+end
+
+assert("MatchData#to_s") do
+  md = Regexp.new("bc").match("abcde")
+  assert_equal "bc", md.to_s
+end
+
 assert("MatchData#begin / #end") do
   re = Regexp.new("bc")
   md = re.match("abcde")