public void Validate(LexerSpec lexer)
{
var modeReferenceErrors = Modes.Except(lexer.Modes).ToList();
if (modeReferenceErrors.Any())
{
throw new Exception($"Rule '{Name}' references mode(s) not in lexer spec: '{string.Join("', '", modeReferenceErrors)}'");
}
ValidateCommands(lexer);
Expression.Validate(lexer);
}
