In my Work Backup program I configure the script with a list of things to do, thus: 
my @locations= (
   [ source => 'D:\\dev' ],
   [ docs => 'D:\\My Documents' ],
   [ source => 'F:\\dev' ],
   [ docs => 'F:\\Documents' ],
   [ norule => 'D:\\Program Files\\util']
   );

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Now, I want to make it more complex, allowing for multiple rules and modifiers to be applied to one item. So, what's a good way to do this?

In Tk, a general mechanism is used for passing arguments that begin with a dash, followed by arguments for that particular flag. Some general code pulls that out and deals with it.

[ qw ( -this -that 5 6 -other /path/etc/foo ) ],

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Another idea is to have one item per list element, period, and if it had arguments include it in a nested list. E.g. 
[ '-this', [ that => 5, 6 ], '-other', '/path/etc/foo' ],

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This is easier to process and clear that the 5 and 6 go with the 'that'.

In the script, each modifier will be implemented via a callback, which takes the extra arguments too, and the callback can modify the job's object state in some way.

Does anyone else have any suggestions on a good way to do this? "good" for both the user configuring the thing, and the implementation.

—John

In reply to Ways of Passing Configuration Parameters by John M. Dlugosz

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