Parser constructor Null safety

Parser(
  1. String? _commandName,
  2. ArgParser _grammar,
  3. Queue<String> _args,
  4. [Parser? _parent,
  5. List<String>? rest]
)

Implementation

Parser(this._commandName, this._grammar, this._args,
    [this._parent, List<String>? rest])
    : _rest = [...?rest];