Walter Bright wrote:
The trouble with a generator using the caller's stack is that then the generator cannot recursively call itself (such as if it was walking a tree). In order to work properly in the general case, a generator has to allocate all its local variables on the heap.
Which concept of generators do you refer to? The stack-based generators that I suggested do in fact work recursively. A generator can obtain its values from other generators or even recursively from itself without needing heap space anywhere.
