Walter Bright wrote:
Norbert Nemec wrote:
Regan Heath wrote:
So, these generators are essentially inline functions?
No. They may be inlined, but this is just an optimization just like
for regular functions. If they are not inlined, these generators are
simply functions with a special calling convention that allows them to
retain their local data and execution point on the stack in between
calls.
I did work out the assembly code for this some time ago and it worked
nicely. Very similar to what is needed for co-routines, but it is
possible to do everything on the stack.
How is that different from a local delegate that refers to local
variables of the function it is lexically nested in?
It is pretty much the same in the trivial case of one loop having one
generator in the loop header. The difference shows up in more complex cases:
* Try to design a "filter" (a generator that takes another generator as
argument) - may be possible but probably ugly to implement.
* Try to run a loop that pulls its values pairwise from two independent
generators - I don't see a way to do this without serious mental acrobatic.
Apart from that, I guess that the runtime overhead without inlining is
somewhat different. Would have to investigate that in more detail.
