Unsupplied Value

The Unsupplied class implements the value used to initialize unsupplied keyword parameters to functions.

There is one distinguished instance of the Unsupplied class in the reserved system variable unsupplied .

You can test to see whether a caller has supplied an optional keyword argument by comparing it with unsupplied .

Constructor

Unsupplied 

EXAMPLE

   fn testFunction arg1 optionalArg2: =
   (
     if optionalArg2 == unsupplied then
       format "Optional Argument Was Not Supplied!\n"
     else
       format "Arguments Were Supplied, Their Sum Was %!\n" (arg1+optionalArg2)
   )

   testFunction 10.0
   --> Optional Argument Was Not Supplied!

   testFunction 10.0 optionalArg2:32
   --> Arguments Were Supplied, Their Sum Was 42.0!