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petitparser/lib/src/debug/continuation.dart

-part of debug;
-
-/**
- * Handler function for the [ContinuationParser].
- */
-typedef Result ContinuationHandler(
-    Result continuation(Context context), Context context);
-
-/**
- * Continuation parser that when activated captures a continuation function
- * and passes it together with the current context into the handler.
- *
- * Handlers are not required to call the continuation, but can completely ignore
- * it, call it multiple times, and/or store it away for later use. Similarly
- * handlers can modify the current context and/or modify the returned result.
- *
- * The following example shows a simple wrapper. Messages are printed before and
- * after the `digit()` parser is activated:
- *
- *     var wrapped = digit();
- *     var parser = new ContinuationParser(wrapped, (continuation, context) {
- *       print('Parser will be activated, the context is $context.');
- *       var result = continuation(context);
- *       print('Parser was activated, the result is $result.');
- *       return result;
- *     });
- *
- * See [profile], [progress], and [trace] for more elaborate examples.
- */
-class ContinuationParser extends DelegateParser {
-  final ContinuationHandler handler;
-
-  ContinuationParser(parser, this.handler) : super(parser);
-
-  @override
-  Result parseOn(Context context) {
-    return handler((result) => super.parseOn(result), context);
-  }
-
-  @override
-  Parser copy() => new ContinuationParser(children[0], handler);
-}