Question: How do list the optionals of an optional argument in procedure (like 'color')?

In this document, I think that is the relevent section. But I couldnt understand it.


I want something like this





>plot(sin(x),color=ABC); # error

>plot(sin(x),color=CBA);# error

optional, but works fine within a given sets of choices.


How do I write a procedure like that?



Please Wait...