Version 2.19.0-425.0.dev

Merge 38ac261 into dev

Author: Dart CI

pkg/_fe_analyzer_shared/lib/src/parser/forwarding_listener.dart

@@ -1864,6 +1864,11 @@ class ForwardingListener implements Listener {
     listener?.handleSpreadExpression(spreadToken);
   }
 
+  @override
+  void handleRestPattern(Token dots, {required bool hasSubPattern}) {
+    listener?.handleRestPattern(dots, hasSubPattern: hasSubPattern);
+  }
+
   @override
   void handleStringJuxtaposition(Token startToken, int literalCount) {
     listener?.handleStringJuxtaposition(startToken, literalCount);

pkg/_fe_analyzer_shared/lib/src/parser/identifier_context.dart

@@ -370,6 +370,36 @@ bool looksLikeExpressionStart(Token next) =>
     optional('++', next) ||
     optional('--', next);
 
+/// Returns `true` if the given [token] should be treated like the start of a
+/// pattern for the purposes of recovery.
+///
+/// Note: since the syntax for patterns is very similar to that for expressions,
+/// we mostly re-use [looksLikeExpressionStart].
+bool looksLikePatternStart(Token next) =>
+    next.isIdentifier ||
+    next.type == TokenType.DOUBLE ||
+    next.type == TokenType.HASH ||
+    next.type == TokenType.HEXADECIMAL ||
+    next.type == TokenType.IDENTIFIER ||
+    next.type == TokenType.INT ||
+    next.type == TokenType.STRING ||
+    optional('null', next) ||
+    optional('false', next) ||
+    optional('true', next) ||
+    optional('{', next) ||
+    optional('(', next) ||
+    optional('[', next) ||
+    optional('[]', next) ||
+    optional('<', next) ||
+    optional('<=', next) ||
+    optional('>', next) ||
+    optional('>=', next) ||
+    optional('!=', next) ||
+    optional('==', next) ||
+    optional('var', next) ||
+    optional('final', next) ||
+    optional('const', next);
+
 /// Return `true` if the given [token] should be treated like the start of
 /// a new statement for the purposes of recovery.
 bool looksLikeStatementStart(Token token) => isOneOfOrEof(token, const [

pkg/_fe_analyzer_shared/lib/src/parser/listener.dart

@@ -1673,6 +1673,13 @@ class Listener implements UnescapeErrorListener {
     logEvent("SpreadExpression");
   }
 
+  /// Called after parsing an element of a list or map pattern that starts with
+  /// `...`.  Substructures:
+  /// - pattern (if hasSubPattern is `true`)
+  void handleRestPattern(Token dots, {required bool hasSubPattern}) {
+    logEvent('RestPattern');
+  }
+
   /// Handle the start of a function typed formal parameter.  Substructures:
   /// - type variables
   void beginFunctionTypedFormalParameter(Token token) {}

pkg/_fe_analyzer_shared/lib/src/parser/parser_impl.dart

@@ -75,6 +75,7 @@ import 'identifier_context.dart'
     show
         IdentifierContext,
         looksLikeExpressionStart,
+        looksLikePatternStart,
         okNextValueInFormalParameter;
 
 import 'identifier_context_impl.dart'
@@ -9493,7 +9494,18 @@ class Parser {
         token = next;
         break;
       }
-      token = parsePattern(token, isRefutableContext: isRefutableContext);
+      if (optional('...', next)) {
+        Token dots = next;
+        token = next;
+        next = token.next!;
+        bool hasSubPattern = looksLikePatternStart(next);
+        if (hasSubPattern) {
+          token = parsePattern(token, isRefutableContext: isRefutableContext);
+        }
+        listener.handleRestPattern(dots, hasSubPattern: hasSubPattern);
+      } else {
+        token = parsePattern(token, isRefutableContext: isRefutableContext);
+      }
       next = token.next!;
       ++count;
       if (!optional(',', next)) {

pkg/_fe_analyzer_shared/lib/src/parser/type_info.dart

@@ -359,14 +359,15 @@ TypeInfo computeVariablePatternType(Token token) {
   if (!identical(afterType, token)) {
     Token next = afterType.next!;
     if (next.isIdentifier) {
-      if (optional('as', next)) {
-        // We've seen `TYPE as`.  `as` is a built-in identifier, so this
-        // *could* be a variable pattern.  Or it could be that TYPE should
-        // have been parsed as a pattern.  It's probably not a variable
-        // pattern (since `as` is an unusual variable name), so we'll only
-        // treat it as a variable pattern if the token following `as` is
-        // something that could legitimately follow a variable pattern (and
-        // hence couldn't introduce a type).
+      if (optional('as', next) || optional('when', next)) {
+        // We've seen `TYPE as` or `TYPE when`.  `as` is a built-in identifier
+        // and `when` is a pseudo-keyword, so this *could* be a variable
+        // pattern.  Or it could be that TYPE should have been parsed as a
+        // pattern.  It's probably not a variable pattern (since `as` and `when`
+        // are unusual variable names), so we'll only treat it as a variable
+        // pattern if the token following `as` or `when` is something that could
+        // legitimately follow a variable pattern (and hence couldn't introduce
+        // a type).
         if (!mayFollowVariablePattern(next.next!)) {
           return noType;
         }
@@ -448,6 +449,7 @@ const Set<String> _allowedTokensAfterVariablePattern = {
   '}',
   ']',
   'as',
+  'when',
   '?',
   '!'
 };

pkg/analyzer/lib/src/clients/build_resolvers/build_resolvers.dart

@@ -18,6 +18,7 @@ import 'package:analyzer/src/summary/summary_sdk.dart';
 import 'package:analyzer/src/summary2/package_bundle_format.dart';
 
 export 'package:analyzer/src/context/packages.dart' show Packages, Package;
+export 'package:analyzer/src/dart/analysis/byte_store.dart' show ByteStore;
 export 'package:analyzer/src/dart/analysis/experiments.dart'
     show ExperimentStatus;
 export 'package:analyzer/src/generated/engine.dart'
@@ -37,6 +38,7 @@ AnalysisDriverForPackageBuild createAnalysisDriver({
   required AnalysisOptions analysisOptions,
   required List<UriResolver> uriResolvers,
   required Packages packages,
+  ByteStore? byteStore,
 }) {
   var sdkBundle = PackageBundleReader(sdkSummaryBytes);
   var sdk = SummaryBasedDartSdk.forBundle(sdkBundle);
@@ -55,7 +57,7 @@ AnalysisDriverForPackageBuild createAnalysisDriver({
     scheduler: scheduler,
     logger: logger,
     resourceProvider: resourceProvider,
-    byteStore: MemoryByteStore(),
+    byteStore: byteStore ?? MemoryByteStore(),
     sourceFactory: sourceFactory,
     analysisOptions: analysisOptions as AnalysisOptionsImpl,
     externalSummaries: dataStore,

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -4972,6 +4972,12 @@ class AstBuilder extends StackListener {
         operator: token, operand: pop() as ExpressionImpl));
   }
 
+  @override
+  void handleRestPattern(Token dots, {required bool hasSubPattern}) {
+    var subPattern = hasSubPattern ? pop() as DartPatternImpl : null;
+    push(RestPatternElementImpl(operator: dots, pattern: subPattern));
+  }
+
   @override
   void handleScript(Token token) {
     assert(identical(token.type, TokenType.SCRIPT_TAG));