Add boolean parse

Closes #51026

Co-authored-by: Renato Burton <[email protected]>
GitOrigin-RevId: e85a56c
Change-Id: I60f92c594830ef0438ecd92b4c83cec609054326
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/279746
Reviewed-by: Lasse Nielsen <[email protected]>
Reviewed-by: Sigmund Cherem <[email protected]>
Commit-Queue: Lasse Nielsen <[email protected]>

Author: 2 people

CHANGELOG.md

@@ -29,6 +29,7 @@
   * `StringConversionSink`
 
 #### `dart:core`
+- Added `bool.parse` and `bool.tryParse` static methods.
 
 - **Breaking change** [#49529][]:
   - Removed the deprecated `List` constructor, as it wasn't null safe.

pkg/analyzer_cli/test/data/sky_engine/lib/core.dart

@@ -34,7 +34,9 @@ abstract class String implements Comparable<String> {
   List<int> get codeUnits;
 }
 
-class bool extends Object {}
+class bool extends Object {
+  static bool parse(String source, {bool caseSensitive = false}) => false;
+}
 
 abstract class num implements Comparable<num> {
   bool operator <(num other);

sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart

@@ -703,6 +703,16 @@ class bool {
         'bool.hasEnvironment can only be used as a const constructor');
   }
 
+  @patch
+  static bool parse(String source, {bool caseSensitive = true}) =>
+      Primitives.parseBool(source, caseSensitive) ??
+      (throw FormatException("Invalid boolean", source));
+
+  @patch
+  static bool? tryParse(String source, {bool caseSensitive = true}) {
+    return Primitives.parseBool(source, caseSensitive);
+  }
+
   @patch
   int get hashCode => super.hashCode;
 

sdk/lib/_internal/js_dev_runtime/private/js_helper.dart

@@ -159,6 +159,31 @@ class Primitives {
     return result;
   }
 
+  static bool? parseBool(
+      @nullCheck String source, @nullCheck bool caseSensitive) {
+    if (caseSensitive) {
+      return JS('bool', r'# == "true" || # != "false" && null', source, source);
+    }
+    return _compareIgnoreCase(source, "true")
+        ? true
+        : _compareIgnoreCase(source, "false")
+            ? false
+            : null;
+  }
+
+  /// Compares a string against an ASCII lower-case letter-only string.
+  ///
+  /// Returns `true` if the [input] has the same length and same letters
+  /// as [lowerCaseTarget], `false` if not.
+  static bool _compareIgnoreCase(String input, String lowerCaseTarget) {
+    if (input.length != lowerCaseTarget.length) return false;
+    var delta = 0x20;
+    for (var i = 0; i < input.length; i++) {
+      delta |= input.codeUnitAt(i) ^ lowerCaseTarget.codeUnitAt(i);
+    }
+    return delta == 0x20;
+  }
+
   /** `r"$".codeUnitAt(0)` */
   static const int DOLLAR_CHAR_VALUE = 36;
 

sdk/lib/_internal/js_runtime/lib/core_patch.dart

@@ -580,6 +580,16 @@ class String {
 class bool {
   @patch
   int get hashCode => super.hashCode;
+
+  @patch
+  static bool parse(String source, {bool caseSensitive = true}) =>
+      tryParse(source, caseSensitive: caseSensitive) ??
+      (throw FormatException("Invalid boolean", source));
+
+  @patch
+  static bool? tryParse(String source, {bool caseSensitive = true}) {
+    return Primitives.parseBool(source, caseSensitive);
+  }
 }
 
 @patch

sdk/lib/_internal/js_runtime/lib/js_helper.dart

@@ -388,15 +388,13 @@ class Primitives {
   static bool? parseBool(String source, bool caseSensitive) {
     checkNotNullable(source, "source");
     checkNotNullable(caseSensitive, "caseSensitive");
-    // The caseSensitive defaults to true.
     if (caseSensitive) {
       return source == "true"
           ? true
           : source == "false"
               ? false
               : null;
     }
-    // Compare case-sensitive when caseSensitive is false.
     return _compareIgnoreCase(source, "true")
         ? true
         : _compareIgnoreCase(source, "false")

sdk/lib/_internal/vm_shared/lib/bool_patch.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import "dart:_internal" show patch;
+import "dart:_internal" show patch, checkNotNullable;
 
 @patch
 @pragma("vm:entry-point")
@@ -20,4 +20,50 @@ class bool {
   int get hashCode => this ? 1231 : 1237;
 
   int get _identityHashCode => this ? 1231 : 1237;
+
+  @patch
+  static bool parse(String source, {bool caseSensitive = true}) {
+    checkNotNullable(source, "source");
+    checkNotNullable(caseSensitive, "caseSensitive");
+    if (caseSensitive) {
+      return source == "true" ||
+          source != "false" &&
+              (throw FormatException("Invalid boolean", source));
+    }
+    // Ignore case-sensitive when `caseSensitive` is false.
+    return _compareIgnoreCase(source, "true") ||
+        !_compareIgnoreCase(source, "false") &&
+            (throw FormatException("Invalid boolean", source));
+  }
+
+  @patch
+  static bool? tryParse(String source, {bool caseSensitive = true}) {
+    checkNotNullable(source, "source");
+    checkNotNullable(caseSensitive, "caseSensitive");
+    if (caseSensitive) {
+      return source == "true"
+          ? true
+          : source == "false"
+              ? false
+              : null;
+    }
+    return _compareIgnoreCase(source, "true")
+        ? true
+        : _compareIgnoreCase(source, "false")
+            ? false
+            : null;
+  }
+
+  /// Compares a string against an ASCII lower-case letter-only string.
+  ///
+  /// Returns `true` if the [input] has the same length and same letters
+  /// as [lowerCaseTarget], `false` if not.
+  static bool _compareIgnoreCase(String input, String lowerCaseTarget) {
+    if (input.length != lowerCaseTarget.length) return false;
+    var delta = 0x20;
+    for (var i = 0; i < input.length; i++) {
+      delta |= input.codeUnitAt(i) ^ lowerCaseTarget.codeUnitAt(i);
+    }
+    return delta == 0x20;
+  }
 }

sdk/lib/core/bool.dart

@@ -94,6 +94,68 @@ final class bool {
   //ignore: const_factory
   external const factory bool.hasEnvironment(String name);
 
+  /// Parses [source] as an, optionally case-insensitive, boolean literal.
+  ///
+  /// If [caseSensitive] is `true`, which is the default,
+  /// the only accepted inputs are the strings `"true"` and `"false"`,
+  /// which returns the results `true` and `false` respectively.
+  ///
+  /// If [caseSensitive] is `false`, any combination of upper and lower case
+  /// ASCII letters in the words `"true"` and `"false"` are accepted,
+  /// as if the input was first lower-cased.
+  ///
+  /// Throws a [FormatException] if the [source] string does not contain
+  /// a valid boolean literal.
+  ///
+  /// Rather than throwing and immediately catching the [FormatException],
+  /// instead use [tryParse] to handle a potential parsing error.
+  ///
+  /// Example:
+  /// ```dart
+  /// print(bool.tryParse('true')); // true
+  /// print(bool.tryParse('false')); // false
+  /// print(bool.tryParse('TRUE')); // throws FormatException
+  /// print(bool.tryParse('TRUE', caseSensitive: false)); // true
+  /// print(bool.tryParse('FALSE', caseSensitive: false)); // false
+  /// print(bool.tryParse('NO')); // throws FormatException
+  /// print(bool.tryParse('YES')); // throws FormatException
+  /// print(bool.tryParse('0')); // throws FormatException
+  /// print(bool.tryParse('1')); // throws FormatException
+  /// ```
+  @Since("3.0")
+  external static bool parse(String source, {bool caseSensitive = true});
+
+  /// Parses [source] as an, optionally case-insensitive, boolean literal.
+  ///
+  /// If [caseSensitive] is `true`, which is the default,
+  /// the only accepted inputs are the strings `"true"` and `"false"`,
+  /// which returns the results `true` and `false` respectively.
+  ///
+  /// If [caseSensitive] is `false`, any combination of upper and lower case
+  /// ASCII letters in the words `"true"` and `"false"` are accepted,
+  /// as if the input was first lower-cased.
+  ///
+  /// Returns `null` if the [source] string does not contain a valid
+  /// boolean literal.
+  ///
+  /// If the input can be assumed to be valid, use [bool.parse] to avoid
+  /// having to deal with a possible `null` result.
+  ///
+  /// Example:
+  /// ```dart
+  /// print(bool.tryParse('true')); // true
+  /// print(bool.tryParse('false')); // false
+  /// print(bool.tryParse('TRUE')); // null
+  /// print(bool.tryParse('TRUE', caseSensitive: false)); // true
+  /// print(bool.tryParse('FALSE', caseSensitive: false)); // false
+  /// print(bool.tryParse('NO')); // null
+  /// print(bool.tryParse('YES')); // null
+  /// print(bool.tryParse('0')); // null
+  /// print(bool.tryParse('1')); // null
+  /// ```
+  @Since("3.0")
+  external static bool? tryParse(String source, {bool caseSensitive = true});
+
   external int get hashCode;
 
   /// The logical conjunction ("and") of this and [other].

tests/corelib/bool_parse_test.dart

@@ -0,0 +1,23 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// SharedOptions=-Da=true -Db=false -Dc=NOTBOOL -Dd=True
+
+import "package:expect/expect.dart";
+
+main() {
+  Expect.isTrue(bool.parse('true'));
+  Expect.isFalse(bool.parse('false'));
+  Expect.isTrue(bool.parse('TRUE', caseSensitive: false));
+  Expect.isFalse(bool.parse('FALSE', caseSensitive: false));
+  Expect.isTrue(bool.parse('true', caseSensitive: true));
+  Expect.isFalse(bool.parse('false', caseSensitive: true));
+  Expect.throws(() => bool.parse('True'));
+  Expect.throws(() => bool.parse('False'));
+  Expect.throws(() => bool.parse('y'));
+  Expect.throws(() => bool.parse('n'));
+  Expect.throws(() => bool.parse('0'));
+  Expect.throws(() => bool.parse('1'));
+  Expect.throws(() => bool.parse('TRUE', caseSensitive: true));
+  Expect.throws(() => bool.parse('FALSE', caseSensitive: true));
+}

tests/corelib/bool_try_parse_test.dart

@@ -0,0 +1,21 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// SharedOptions=-Da=true -Db=false -Dc=NOTBOOL -Dd=True
+
+import "package:expect/expect.dart";
+
+main() {
+  Expect.isTrue(bool.tryParse('true'));
+  Expect.isFalse(bool.tryParse('false'));
+  Expect.isTrue(bool.tryParse('TRUE', caseSensitive: false));
+  Expect.isFalse(bool.tryParse('FALSE', caseSensitive: false));
+  Expect.isNull(bool.tryParse('TRUE'));
+  Expect.isNull(bool.tryParse('FALSE'));
+  Expect.isNull(bool.tryParse('y'));
+  Expect.isNull(bool.tryParse('n'));
+  Expect.isNull(bool.tryParse(' true ', caseSensitive: false));
+  Expect.isNull(bool.tryParse(' false ', caseSensitive: false));
+  Expect.isNull(bool.tryParse('0', caseSensitive: true));
+  Expect.isNull(bool.tryParse('1', caseSensitive: true));
+}