Add docs

pkgs/intl4x/lib/datetime_format.dart

@@ -9,6 +9,9 @@ export 'src/datetime_format/datetime_format_options.dart';
 export 'src/options.dart';
 
 extension DateTimeFormatIntl4x on DateTime {
+  /// Format a date in a locale-dependent manner.
+  ///
+  /// For more options, use [Intl.datetimeFormat] directly.
   String toLocaleDateString([Locale? locale]) =>
       Intl(locale: locale).datetimeFormat().format(this);
 }

pkgs/intl4x/lib/list_format.dart

@@ -3,12 +3,37 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'intl4x.dart';
+import 'src/list_format/list_format_options.dart';
 
 export 'src/list_format/list_format.dart';
 export 'src/list_format/list_format_options.dart';
 export 'src/options.dart';
 
 extension ListFormatIntl4x on List<String> {
-  String toLocaleFormat([Locale? locale]) =>
-      Intl(locale: locale).listFormat().format(this);
+  /// Join a list in a locale-dependent manner using `and`-based grouping.
+  ///
+  /// Example: "A, B, and C". See also [Type.and].
+  ///
+  /// For more options, use [Intl.listFormat] directly.
+  String joinAnd([Locale? locale]) => Intl(locale: locale)
+      .listFormat(const ListFormatOptions(type: Type.and))
+      .format(this);
+
+  /// Join a list in a locale-dependent manner using `or`-based grouping.
+  ///
+  /// Example: "A, B, or C". See also [Type.or].
+  ///
+  /// For more options, use [Intl.listFormat] directly.
+  String joinOr([Locale? locale]) => Intl(locale: locale)
+      .listFormat(const ListFormatOptions(type: Type.or))
+      .format(this);
+
+  /// Join a list in a locale-dependent manner using unit-based grouping.
+  ///
+  /// Example: "A, B, C". See also [Type.unit].
+  ///
+  /// For more options, use [Intl.listFormat] directly.
+  String joinUnit([Locale? locale]) => Intl(locale: locale)
+      .listFormat(const ListFormatOptions(type: Type.or))
+      .format(this);
 }

pkgs/intl4x/test/list_format_test.dart

@@ -62,6 +62,8 @@ void main() {
   });
 
   testWithFormatting('extension', () {
-    expect(list.toLocaleFormat(enUS), 'A, B, and C');
+    expect(list.joinAnd(enUS), 'A, B, and C');
+    expect(list.joinOr(enUS), 'A, B, or C');
+    expect(list.joinUnit(enUS), 'A, B, C');
   });
 }