More on "optional:N" meanings

Peter Rice peter.rice at
Wed May 2 13:11:56 UTC 2001

James Bonfield wrote:
> In remap the "uppercase" variable (which holds a list of positions) is
> defined to be opt:N (implicitly) and def:"".
> In my code this has unfortunate consequences. I have, in an advanced
> tab, an entry window for the uppercase variable. It has no value
> inserted in it as the  default is "". However the program will not
> let me proceed without filling out that entry as it claims I haven't
> specified a value for a non-optional parameter.

I am beginning to regret that name!!!

Think of it as an extra option for the user. The universal command line
qualifier '-options' makes the program prompt for a value for 'uppercase',
but otherwise there is no difference. It can always be put on the command
line (by the user or through your interface).

'optionalextra' might be a better name for the ACD attribute ... without
breaking any current ACD files. Would that make it less confusing?



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

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