From 559f0a165698bd8defbf09891215bb56f55fc156 Mon Sep 17 00:00:00 2001
From: fglock <fglock@gmail.com>
Date: Sat, 19 Oct 2024 16:02:09 +0200
Subject: [PATCH] update to Java 21

---
 .idea/compiler.xml                            |  2 +-
 .idea/misc.xml                                |  2 +-
 README.md                                     |  2 +-
 build.gradle                                  |  2 +-
 pom.xml                                       |  4 +--
 .../runtime/HashSpecialVariable.java          | 36 ++++---------------
 6 files changed, 13 insertions(+), 35 deletions(-)

diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index fb7f4a8a..b86273d9 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="CompilerConfiguration">
-    <bytecodeTargetLevel target="11" />
+    <bytecodeTargetLevel target="21" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 153b3308..965c8c4a 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -15,7 +15,7 @@
     <option name="enabled" value="true" />
     <option name="wasEnabledAtLeastOnce" value="true" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="azul-11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" project-jdk-name="azul-11" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/README.md b/README.md
index 809ee5eb..42f96971 100644
--- a/README.md
+++ b/README.md
@@ -190,7 +190,7 @@ file.
 
 - The project uses the `maven-shade-plugin` for Maven to create a shaded JAR.
 - The project uses the `com.github.johnrengelman.shadow` plugin for Gradle to create a shaded JAR.
-- Both Maven and Gradle configurations are set to use Java 11.
+- Both Maven and Gradle configurations are set to use Java 21.
 
 ## Running the jar file
 
diff --git a/build.gradle b/build.gradle
index b8f6f3a5..fc6820a6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -9,7 +9,7 @@ version = '1.0-SNAPSHOT'
 
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(11)
+        languageVersion = JavaLanguageVersion.of(21)
     }
 }
 
diff --git a/pom.xml b/pom.xml
index 65873d36..0c3c54db 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,8 +12,8 @@
     <url>http://maven.apache.org</url>
 
     <properties>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
     </properties>
 
     <dependencies>
diff --git a/src/main/java/org/perlonjava/runtime/HashSpecialVariable.java b/src/main/java/org/perlonjava/runtime/HashSpecialVariable.java
index 65d53846..b5011398 100644
--- a/src/main/java/org/perlonjava/runtime/HashSpecialVariable.java
+++ b/src/main/java/org/perlonjava/runtime/HashSpecialVariable.java
@@ -1,13 +1,11 @@
 package org.perlonjava.runtime;
 
 import java.util.AbstractMap;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import java.util.regex.PatternSyntaxException;
 
 import static org.perlonjava.runtime.RuntimeScalarCache.scalarUndef;
 
@@ -28,36 +26,16 @@ public class HashSpecialVariable extends AbstractMap<String, RuntimeScalar> {
      */
     public HashSpecialVariable(Matcher matcher) {
         this.matcher = matcher;
-        this.namedGroups = extractNamedGroups(matcher.pattern());
-    }
-
-    /**
-     * Extracts named groups and their indices from the given pattern.
-     *
-     * @param pattern the regex pattern
-     * @return a map of named group names to their indices
-     */
-    private Map<String, Integer> extractNamedGroups(Pattern pattern) {
-        Map<String, Integer> namedGroups = new HashMap<>();
-        String regex = pattern.toString();
-        Matcher groupMatcher = Pattern.compile("\\(\\?<([a-zA-Z][a-zA-Z0-9]*)>").matcher(regex);
-        int index = 1; // Group indices start at 1
-
-        while (groupMatcher.find()) {
-            String groupName = groupMatcher.group(1);
-            namedGroups.put(groupName, index++);
-        }
-
-        return namedGroups;
+        this.namedGroups = matcher.pattern().namedGroups();  // Use Java 20's built-in namedGroups support
     }
 
     @Override
     public Set<Entry<String, RuntimeScalar>> entrySet() {
         Set<Entry<String, RuntimeScalar>> entries = new HashSet<>();
         for (String name : namedGroups.keySet()) {
-            int groupIndex = namedGroups.get(name);
-            if (groupIndex != -1 && matcher.group(name) != null) {
-                entries.add(new SimpleEntry<>(name, new RuntimeScalar(matcher.group(name))));
+            String matchedValue = matcher.group(name);  // Use Matcher.group(String name)
+            if (matchedValue != null) {
+                entries.add(new SimpleEntry<>(name, new RuntimeScalar(matchedValue)));
             }
         }
         return entries;
@@ -67,9 +45,9 @@ public Set<Entry<String, RuntimeScalar>> entrySet() {
     public RuntimeScalar get(Object key) {
         if (key instanceof String) {
             String name = (String) key;
-            int groupIndex = namedGroups.getOrDefault(name, -1);
-            if (groupIndex != -1 && matcher.group(groupIndex) != null) {
-                return new RuntimeScalar(matcher.group(groupIndex));
+            String matchedValue = matcher.group(name);  // Use Matcher.group(String name)
+            if (matchedValue != null) {
+                return new RuntimeScalar(matchedValue);
             }
         }
         return scalarUndef;