- When multiple attribute flags are specified for filtering, all parameters that have at least one of them rather than all of them are considered. The latter, à la ksh, looks more useful as the former can also be obtained by running a separate 'typeset' command for each attribute flag.
The current behavior is particularly detrimental for flag specific 'typeset' builtins, like 'export' or 'integer'. For example, 'export' prints all exported parameters. One might expect that 'export -r' prints all read-only exported parameters but in reality it prints all parameters that are either exported or read-only, which to me doesn't look very useful. I also doubt that this is what most users expect from that command.
Philippe