Documentation update for LineSplitter

Adding example of usage

Closes #47621
#47621

GitOrigin-RevId: e2509b5
Change-Id: I1cd79309799d8361c359c4e5194473bc4e46463b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/219280
Reviewed-by: Lasse R.H. Nielsen <[email protected]>
Commit-Queue: Lasse R.H. Nielsen <[email protected]>

Author: jpsiitonen

sdk/lib/convert/line_splitter.dart

@@ -10,12 +10,31 @@ const int _CR = 13;
 
 /// A [StreamTransformer] that splits a [String] into individual lines.
 ///
-/// A line is terminated by either a CR (U+000D), a LF (U+000A), a
-/// CR+LF sequence (DOS line ending),
-/// and a final non-empty line can be ended by the end of the string.
+/// A line is terminated by either:
+/// * a CR, carriage return: U+000D ('\r')
+/// * a LF, line feed (Unix line break): U+000A ('\n') or
+/// * a CR+LF sequence (DOS/Windows line break), and
+/// * a final non-empty line can be ended by the end of the input.
 ///
-/// The returned lines do not contain the line terminators.
-
+/// The resulting lines do not contain the line terminators.
+///
+/// Example:
+/// ```dart
+/// const splitter = LineSplitter();
+/// const sampleText =
+///     'Dart is: \r an object-oriented \n class-based \n garbage-collected '
+///     '\r\n language with C-style syntax \r\n';
+///
+/// final sampleTextLines = splitter.convert(sampleText);
+/// for (var i = 0; i < sampleTextLines.length; i++) {
+///   print('$i: ${sampleTextLines[i]}');
+/// }
+/// // 0: Dart is:
+/// // 1:  an object-oriented
+/// // 2:  class-based
+/// // 3:  garbage-collected
+/// // 4:  language with C-style syntax
+/// ```
 class LineSplitter extends StreamTransformerBase<String, String> {
   const LineSplitter();