From c7926c1f4daa5c40b7999e8429945f5daf392c34 Mon Sep 17 00:00:00 2001
From: monoid <qaswedfr55@gmail.com>
Date: Sun, 29 Jun 2025 16:21:51 +0900
Subject: [PATCH] refactor: optimize CharItem to handle special characters in
 toString method

---
 lib/src/main/kotlin/org/example/RegexItem.kt | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/lib/src/main/kotlin/org/example/RegexItem.kt b/lib/src/main/kotlin/org/example/RegexItem.kt
index 3e0dd77..8f1991e 100644
--- a/lib/src/main/kotlin/org/example/RegexItem.kt
+++ b/lib/src/main/kotlin/org/example/RegexItem.kt
@@ -76,12 +76,11 @@ class AndThenItem(val left: RegexItem, val right: RegexItem) : RegexItem {
 }
 
 class CharItem(val value: String) : RegexItem {
+  companion object {
+    private val META_CHARS = setOf("\\", "+", "*", "?", ".", "(", ")", "|", "[", "]", "^", "$")
+  }
   override fun toString(): String =
-      // escape 특수 문자를 처리하여 출력
-      when (value) {
-        "\\", "+", "*", "?", ".", "(", ")", "|", "[", "]" -> "\\$value"
-        else -> value // 일반 문자 그대로 반환
-      }
+      if (value in META_CHARS) "\\$value" else value
 
   override fun findMatch(str: String, position: Int): AvailableState {
     return when {