[PD-dev] Message dispatching system

[Jonathan Wilkes]

Hi list,
      I learned some more about Pd's message dispatching system while 
adding jump-on-click mouse clicks and bar graphs to "Put" menu arrays:

1) For type-checked args in class_addmethod, you can specify them in any 
order.
2) Pd re-arranges them, putting the symbol/pointer args first and the 
float args last.
3) In the function for the method you have to specify the args in the 
order from #2.

I see graph_array makes use of these in g_graph.c: the args are symbol 
float symbol float float, but the function receives the symbols as the 
first two args.

Was this done to fix a bug or keep something backwards compatible? Are 
there other methods done this way?  In general I think it's much better 
to specify type-checked args in the same order they'll be received by 
the function, meaning symbols/pointers then floats. Otherwise it makes 
it more difficult to track down errors.

-Jonathan