required vs optional

Peter Rice Peter.Rice at
Wed Feb 7 17:07:34 UTC 2001

James Bonfield wrote:
> > If you say "req: Y" then it means required, and will be prompted.
> > If you say "param: Y" this also means required, and will be prompted.
> So for the purposes of the GUI I can just treat them the same and always
> specify the qualifier anyway.


> I still feel that a way of indicating unnecessary or pointless questions would
> be useful. It's additional to required as that just indicates whether or not
> the default value is enough. I'm just trying to think what dialogues
> professional applications are likely to have, and greying-out things on the
> fly is a common technique. The more I think about it the more I'm certain.
> So I propose the following addition to each command line qualifier.
> needed: @expression
> The default is 1. If an expression is specified and it evaluations to 0 then
> the option is not asked for (even with -options) and in GUIs it will be
> greyed-out. For me, this is trivial to do (ie I've already written it).
> Any comments on this proposal?

I don't see how this is different from testing required, parameter and
optional in turn, which is what the code will do.

Basically, needed is 'required or parameter or optional' ... every time.

You would then have the choice of including/excluding the optional ones, just
like a 'real' user.

Peter Rice, LION Bioscience Ltd, Cambridge, UK
peter.rice at +44 1223 224723

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