Relation output

Outputting a relation

Or you could output them as a single row table:

return #( angle: a, distance: d )

Now the calling activity can retrieve these values like so:

track #= /R8/Aircraft.Trackto( target : nearby aircraft.ID )
a = track.Angle; d = track.Distance

This would also work:

a, d = /R8/Aircraft.Trackto( target : nearby aircraft.ID )

Or even:

track #= /R8/Aircraft.Trackto( target : nearby aircraft.ID )
nearby aircraft.(Angle, Distance) #= track  // assign results to attribute values

The name doubling simplification used for input parameters also applies to output parameters. If the variable names in a class method or domain operation match the returned attribute names, there is no need to double them. Therefore, this would also work with the above example:

=>> ( angle, distance )  // variable names match output parameter names