🚀 go-pugleaf

harvey@opl.com (Harvey Reed) writes:

>If programmers want nested functions, it sounds a lot like delegation which
>C++ can handle quite well, as is. Just delegate to another object, or
>your self. This leaves matters fairly explicit.

Two points: firstly, I would not agree that C++ (without overloadable
operator dot) handles delegation well; secondly, delegation can be used
as a poor man's substitute for nested functions, but it does *not* have
the same power/expressiveness that nested functions do. The classic
sort of example where nested functions are useful is

	somefunc(lots of complex parameters) {
	    lots of complex local variables;

	    int compare(const void *ptr1, const void *ptr2) {
		const object *x = (object *)ptr1;
		const object *y = (object *)ptr2;
		// compare x and y using some complex ordering which is
		// dependant on the above parameters and local variables
	    }

	    ...
	    qsort(object_array, n, sizeof(object), compare);
	    ...
	}

Because the interface to qsort() is fixed, the alternative is to use a rather
ugly hack using global variables (well, ok, you can make them file-scope
static variables rather than real global variables). Here delegation doesn't
help.

-- 
Fergus Henderson             fjh@munta.cs.mu.OZ.AU      
This .signature virus is a self-referential statement that is true - but 
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