Re: Substitute for routine_id?
- Posted by jimcbrown (admin) Sep 20, 2010
- 1318 views
? plustwo(6) ? routine_id("plustwo") function plustwo(integer x) return x+2 end function
The first line prints 8, as you would expect the second prints -1, because it can't see forward. As a result, call_back also fails:
This causes much typing and moving functions around into awkward places when using EuGTK.
Is there some way to write a substitute for
call_back(routine_id("foo"))
that will be able to 'see' forward functions?
Or some way to look thru the registry of function names?
This is still awkward, but call_back() does not require that it be placed after a function has declared. Unlike routine_id(), call_back() doesn't care about scope at all, it'll work as long as it's given a valid routine id, no matter where it is.
So you can do this
procedure some_routine_not_called_until_later() call_back(foo_routine_id) ... end procedure ... function foo() ... end function constant foo_routine_id = routine_id("foo") ... some_routine_not_called_until_later()
If you need to generate the call_back() at runtime in a spot before the function was declared and routine_id() called, then this won't help you. (There is a routine id table internally, but you have no way to access that. You could just pass in random numbers to call_back() and hope that you get the right function (e.g. call_back(4) ) but that's obviously a bad idea.)
