Gosub statements operate just like Goto, except that execution
will return to the point of the Gosub statement afterwards, on hitting a return line.
[gosub SomeLabel]If you prefer, you can also use go sub instead of gosub.
In this case we'd jump to a label called SomeOtherLabel, which are
the same as labels used for gotos.
Execution then proceeds until the dialogue sees a return line:
[return]The return line sends execution back to the line after the last gosub line
that was executed. For example:
Player: Hello there
[gosub Greeting]
Player: Thanks!
[goto end]
:Greeting
NPC: Hello to you too!
[return]This is a contrived example, but the sequence would be:
Player: Hello there
NPC: Hello to you too!
Player: Thanks!The point of this is that you could use the "Greeting" sub-dialogue in multiple places in your dialogue, but always return back to the place you invoked it from. This lets you put the same exchange in multiple places in your dialogue without duplicating it, which can be very useful.
It's fine to have another call to gosub inside a bit of sub-dialogue that was
itself reached through a gosub. SUDS keeps a stack of all the gosub lines which
have been executed to get to where you are, and the return statement always returns to the
line after the last gosub executed in that stack, before removing it and
making the previous one the return point.
gosub and return lines adhere to the same rules as Goto Lines.
Essentially they both behave just like goto, just with additional context.