Positional parameters with index/arity ranges may make some input ambiguous. In the below example, the argument at index 1 could be either a port or a file.

Example:

class App {
    @Parameters(index = "0..1", arity = "1..2") int[] portRange;
    @Parameters(index = "1..*") String[] files;
}
App app1 = CommandLine.parse(new App(), "3333", "file1", "file2");

This currently gives picocli.CommandLine$ParameterException: Could not convert 'file1' to int[] for parameter[-1]. (Picocli tries to match options in declared order.)

This requires parsing Strings args which may apply until we encounter one that cannot be converted to the target type.