Update charted to 0.4.8 and roll

packages/petitparser/lib/src/debug/progress.dart

-part of petitparser.debug;
-
-/// Returns a transformed [parser] that when being used to read input
-/// visually prints its progress while progressing.
-///
-/// For example, the snippet
-///
-///     var parser = letter() & word().star();
-///     progress(parser).parse('f123');
-///
-/// produces the following output:
-///
-///     * Instance of 'SequenceParser'
-///     * Instance of 'CharacterParser'[letter expected]
-///     ** Instance of 'PossessiveRepeatingParser'[0..*]
-///     ** Instance of 'CharacterParser'[letter or digit expected]
-///     *** Instance of 'CharacterParser'[letter or digit expected]
-///     **** Instance of 'CharacterParser'[letter or digit expected]
-///     ***** Instance of 'CharacterParser'[letter or digit expected]
-///
-/// Jumps backwards mean that the parser is back-tracking. Often choices can
-/// be reordered to such expensive parses.
-Parser progress(Parser parser, [OutputHandler output = print]) {
-  return transformParser(parser, (each) {
-    return new ContinuationParser(each, (continuation, context) {
-      output('${_repeat(1 + context.position, '*')} $each');
-      return continuation(context);
-    });
-  });
-}