toString method
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 lines = source.split('\n');
final errorLine = lines[line - 1];
final pointer = '${' ' * (column - 1)}^';
return 'ParsingException: $message @ line $line:$column\nsource: \n$errorLine\n$pointer';
}