toString method
override
A string representation of this object.
Some classes have a default textual representation,
often paired with a static parse function (like int.parse).
These classes will provide the textual representation as
their string representation.
Other classes have no meaningful textual representation
that a program will care about.
Such classes will typically override toString to provide
useful information when inspecting the object,
mainly for debugging or logging.
Implementation
@override
String toString() {
final sb = StringBuffer();
sb.write(' ' * depth);
if (ruleName != null) sb.write('$ruleName: ');
if (lexeme != null) sb.write('"$lexeme"');
if (element != null) sb.write(' ($element)');
if (!result.success) sb.write(' <FAILED>');
return sb.toString();
}