Add @useResult to parser constructors to avoid bugs when using the old parser instance.

Author: renggli

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 5.2.0 (unpublished)
+
+- Add `@useResult` to parser constructors to avoid bugs when using the old parser instance.
+
 ## 5.1.0
 
 - Dart 2.18 requirement.

bin/generate_sequence.dart

@@ -61,6 +61,7 @@ Future<void> generateImplementation(int index) async {
   out.writeln('/// Creates a parser that consumes a sequence of $index parsers '
       'and returns a ');
   out.writeln('/// typed sequence [Sequence$index].');
+  out.writeln('@useResult');
   out.writeln('Parser<Sequence$index<${resultTypes.join(', ')}>> '
       'seq$index<${resultTypes.join(', ')}>(');
   for (var i = 0; i < index; i++) {

lib/src/context/context.dart

@@ -19,12 +19,14 @@ class Context {
   /// Returns a result indicating a parse success.
   @inlineVm
   @inlineJs
+  @useResult
   Success<R> success<R>(R result, [int? position]) =>
       Success<R>(buffer, position ?? this.position, result);
 
   /// Returns a result indicating a parse failure.
   @inlineVm
   @inlineJs
+  @useResult
   Failure<R> failure<R>(String message, [int? position]) =>
       Failure<R>(buffer, position ?? this.position, message);
 

lib/src/parser/action/cast.dart

@@ -1,10 +1,13 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
 import '../combinator/delegate.dart';
 
 extension CastParserExtension<T> on Parser<T> {
   /// Returns a parser that casts itself to `Parser<R>`.
+  @useResult
   Parser<R> cast<R>() => CastParser<T, R>(this);
 }
 

lib/src/parser/action/cast_list.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -6,6 +8,7 @@ import '../combinator/delegate.dart';
 extension CastListParserExtension<T> on Parser<T> {
   /// Returns a parser that casts itself to `Parser<List<R>>`. Assumes this
   /// parser to be of type `Parser<List>`.
+  @useResult
   Parser<List<R>> castList<R>() => CastListParser<T, R>(this);
 }
 

lib/src/parser/action/continuation.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -29,6 +31,7 @@ extension ContinuationParserExtension<T> on Parser<T> {
   ///       return result;
   ///     });
   ///
+  @useResult
   Parser<R> callCC<R>(ContinuationHandler<T, R> handler) =>
       ContinuationParser<T, R>(this, handler);
 }

lib/src/parser/action/flatten.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -14,6 +16,7 @@ extension FlattenParserExtension<T> on Parser<T> {
   /// For example, the parser `letter().plus().flatten()` returns `'abc'`
   /// for the input `'abc'`. In contrast, the parser `letter().plus()` would
   /// return `['a', 'b', 'c']` for the same input instead.
+  @useResult
   Parser<String> flatten([String? message]) => FlattenParser<T>(this, message);
 }
 

lib/src/parser/action/map.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -11,6 +13,7 @@ extension MapParserExtension<T> on Parser<T> {
   /// For example, the parser `digit().map((char) => int.parse(char))` returns
   /// the number `1` for the input string `'1'`. If the delegate fails, the
   /// production action is not executed and the failure is passed on.
+  @useResult
   Parser<R> map<R>(
     Callback<T, R> callback, {
     @Deprecated('All callbacks are considered to have side-effects.')

lib/src/parser/action/permute.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -11,6 +13,7 @@ extension PermuteParserExtension<T> on Parser<List<T>> {
   /// For example, the parser `letter().star().permute([0, -1])` returns the
   /// first and last letter parsed. For the input `'abc'` it returns
   /// `['a', 'c']`.
+  @useResult
   Parser<List<T>> permute(List<int> indexes) => PermuteParser<T>(this, indexes);
 }
 

lib/src/parser/action/pick.dart

@@ -1,3 +1,5 @@
+import 'package:meta/meta.dart';
+
 import '../../context/context.dart';
 import '../../context/result.dart';
 import '../../core/parser.dart';
@@ -10,6 +12,7 @@ extension PickParserExtension<T> on Parser<List<T>> {
   ///
   /// For example, the parser `letter().star().pick(-1)` returns the last
   /// letter parsed. For the input `'abc'` it returns `'c'`.
+  @useResult
   Parser<T> pick(int index) => PickParser<T>(this, index);
 }