💡 add more comments / documentation

lib/src/enums/duplicates.dart

@@ -1,7 +1,12 @@
 /// An enum of all available duplicate key handling strategies.
 enum Duplicates {
+  /// Combine duplicate keys into a single key with an array of values.
   combine,
+
+  /// Use the first value for duplicate keys.
   first,
+
+  /// Use the last value for duplicate keys.
   last;
 
   @override

lib/src/enums/format.dart

@@ -2,9 +2,11 @@ typedef Formatter = String Function(String value);
 
 /// An enum of all supported URI component encoding formats.
 enum Format {
+  /// https://datatracker.ietf.org/doc/html/rfc1738
   rfc1738(_rfc1738Formatter),
 
-  /// default
+  /// https://datatracker.ietf.org/doc/html/rfc3986
+  /// (default)
   rfc3986(_rfc3986Formatter);
 
   const Format(this.formatter);

lib/src/enums/list_format.dart

@@ -2,9 +2,20 @@ typedef ListFormatGenerator = String Function(String prefix, [String? key]);
 
 /// An enum of all available list format options.
 enum ListFormat {
+  /// Use brackets to represent list items, for example
+  /// `foo[]=123&foo[]=456&foo[]=789`
   brackets(_brackets),
+
+  /// Use commas to represent list items, for example
+  /// `foo=123,456,789`
   comma(_comma),
+
+  /// Repeat the same key to represent list items, for example
+  /// `foo=123&foo=456&foo=789`
   repeat(_repeat),
+
+  /// Use indices in brackets to represent list items, for example
+  /// `foo[0]=123&foo[1]=456&foo[2]=789`
   indices(_indices);
 
   const ListFormat(this.generator);

lib/src/models/decode_options.dart

@@ -90,7 +90,7 @@ final class DecodeOptions with EquatableMixin {
   /// option.
   final num parameterLimit;
 
-  /// Change the duplicate ket handling strategy
+  /// Change the duplicate key handling strategy
   final Duplicates duplicates;
 
   /// Set to [true] to ignore the leading question mark query prefix in the encoded input.

lib/src/models/undefined.dart

@@ -1,4 +1,4 @@
-/// Internal model to distinguish between null and not set value
+/// Internal model to distinguish between [null] and not set value
 final class Undefined {
   const Undefined();
 }