dot_access - hpgDesigns/hpgdesigns-dev.io GitHub Wiki

In EDL, dot access refers to expressions of the form a.b, and can be used in a number of ways.

Typically when dot-based access is brought up, it is referring to the method inherited from GML, in which a is an integer referencing an instance ID or object index, and b is a local variable. This expression will look up an object with either an ID or Object index of a, then access b from within its scope. This is useful for objects and instances accessing a local variable of another object or instance, either to read or change it.

EDL also inherits the dot operator from C++. It can therefore also be used to access explicit fields in structures and classes, whether the base a is itself an instance of that structure, or a pointer to such an instance.

Finally, functions can also be accessed in this way, which is not a feature of GML or C++ (except as class members). The most obvious example of this is class members, such as a.func() where a is again an instance of a structure/class, and func is a member function of that class. Of course, this is only useful if said structure/class already defined such a function.

The more interesting implication is instance-scoped functions, for example, a.instance_destroy() would function exactly the same as with (a) instance_destroy(). Note that instance-scoped functions are not implemented at this time, but are planned for the near future. In the meantime, simply use with as a workaround. Member functions and field access, however, are implemented.