From 46a07148dc678688eed6b7b30c9e2573561949ef Mon Sep 17 00:00:00 2001
From: Terence Parr <parrt@antlr.org>
Date: Thu, 10 Mar 2022 17:45:23 -0800
Subject: [PATCH] Use int array not string for ATN in Dart (#3578)

---
 .../org/antlr/v4/test/runtime/dart/BaseDartTest.java  |  2 +-
 runtime/Dart/lib/src/parser.dart                      | 11 ++++-------
 runtime/Dart/lib/src/recognizer.dart                  |  2 +-
 .../org/antlr/v4/tool/templates/codegen/Dart/Dart.stg | 10 ++++++----
 tool/src/org/antlr/v4/codegen/target/DartTarget.java  |  2 +-
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/runtime-testsuite/test/org/antlr/v4/test/runtime/dart/BaseDartTest.java b/runtime-testsuite/test/org/antlr/v4/test/runtime/dart/BaseDartTest.java
index 30e3456513..dbfbb278f5 100644
--- a/runtime-testsuite/test/org/antlr/v4/test/runtime/dart/BaseDartTest.java
+++ b/runtime-testsuite/test/org/antlr/v4/test/runtime/dart/BaseDartTest.java
@@ -296,7 +296,7 @@ private String locateTool(String tool) {
 
 		final String[] roots = isWindows()
 				? new String[]{"C:\\tools\\dart-sdk\\bin\\"}
-				: new String[]{"/usr/local/bin/", "/opt/local/bin/", "/usr/bin/", "/usr/lib/dart/bin/", "/usr/local/opt/dart/libexec"};
+				: new String[]{"/usr/local/bin/", "/opt/local/bin/", "/opt/homebrew/bin/", "/usr/bin/", "/usr/lib/dart/bin/", "/usr/local/opt/dart/libexec"};
 
 		for (String root : roots) {
 			for (String t : tools) {
diff --git a/runtime/Dart/lib/src/parser.dart b/runtime/Dart/lib/src/parser.dart
index 65fb472bfa..de002e377f 100644
--- a/runtime/Dart/lib/src/parser.dart
+++ b/runtime/Dart/lib/src/parser.dart
@@ -27,7 +27,7 @@ abstract class Parser extends Recognizer<ParserATNSimulator> {
   /// bypass alternatives.
   ///
   /// @see ATNDeserializationOptions#isGenerateRuleBypassTransitions()
-  static final Map<String, ATN> bypassAltsAtnCache = {};
+  ATN? bypassAltsAtnCache;
 
   /// The error handling strategy for the parser. The default value is a new
   /// instance of [DefaultErrorStrategy].
@@ -295,16 +295,13 @@ abstract class Parser extends Recognizer<ParserATNSimulator> {
           'The current parser does not support an ATN with bypass alternatives.');
     }
 
-    var result = bypassAltsAtnCache[serializedATN];
-    if (result == null) {
+    if (bypassAltsAtnCache == null) {
       final deserializationOptions = ATNDeserializationOptions(false);
       deserializationOptions.setGenerateRuleBypassTransitions(true);
-      result = ATNDeserializer(deserializationOptions)
-          .deserialize(serializedATN!.codeUnits);
-      bypassAltsAtnCache[serializedATN!] = result;
+      bypassAltsAtnCache = ATNDeserializer(deserializationOptions).deserialize(serializedATN);
     }
 
-    return result;
+    return bypassAltsAtnCache!;
   }
 
   /// The preferred method of getting a tree pattern. For example, here's a
diff --git a/runtime/Dart/lib/src/recognizer.dart b/runtime/Dart/lib/src/recognizer.dart
index dbac8f0fb3..a46edbe3bd 100644
--- a/runtime/Dart/lib/src/recognizer.dart
+++ b/runtime/Dart/lib/src/recognizer.dart
@@ -85,7 +85,7 @@ abstract class Recognizer<ATNInterpreter extends ATNSimulator> {
   ///
   /// <p>For interpreters, we don't know their serialized ATN despite having
   /// created the interpreter from it.</p>
-  String? get serializedATN {
+  List<int> get serializedATN {
     throw UnsupportedError('there is no serialized ATN');
   }
 
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Dart/Dart.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Dart/Dart.stg
index 059b845f5f..769b5cc0ee 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Dart/Dart.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Dart/Dart.stg
@@ -217,7 +217,7 @@ class <parser.name> extends <superClass; null="Parser"> {
   String get grammarFileName => '<parser.grammarFileName>';
 
   @override
-  String get serializedATN => _serializedATN;
+  List\<int> get serializedATN => _serializedATN;
 
   @override
   ATN getATN() {
@@ -839,7 +839,7 @@ class <lexer.name> extends <superClass; null="Lexer"> {
   }
 
   @override
-  String get serializedATN => _serializedATN;
+  List\<int> get serializedATN => _serializedATN;
 
   @override
   String get grammarFileName => '<lexer.grammarFileName>';
@@ -853,10 +853,12 @@ class <lexer.name> extends <superClass; null="Lexer"> {
 >>
 
 SerializedATN(model) ::= <<
-static const String _serializedATN = '<model.serialized; wrap={'<\n><\t>'}>';
+static const List\<int> _serializedATN = [
+    <model.serialized: {s | <s>}; separator=",", wrap>
+];
 
 static final ATN _ATN =
-    ATNDeserializer().deserialize(_serializedATN.codeUnits);
+    ATNDeserializer().deserialize(_serializedATN);
 >>
 
 /// Using a type to init value map, try to init a type; if not in table
diff --git a/tool/src/org/antlr/v4/codegen/target/DartTarget.java b/tool/src/org/antlr/v4/codegen/target/DartTarget.java
index 066d37100e..64dc2ee3b5 100644
--- a/tool/src/org/antlr/v4/codegen/target/DartTarget.java
+++ b/tool/src/org/antlr/v4/codegen/target/DartTarget.java
@@ -73,7 +73,7 @@ protected STGroup loadTemplates() {
 
 	@Override
 	public boolean isATNSerializedAsInts() {
-		return false;
+		return true;
 	}
 
 	@Override