Re: [stack] Generators revisited

Don Groves <[email protected]> wrote:
> In rethinking the design of generators, it occurred to me that a
> generator is in fact a closure. I'm not familiar enough with the
> literature yet to know if closures already have an accepted
> methodology in this group, so please enlighten me if this is so.

Sure is! Actually, I kinda assumed that was going to be how you'd
implement them :-).

> A generator might look like [[f] a b ..] where f is the generation
> function and a, b, etc, are its static data.  A new combinator,
> generate (as suggested by Billy), would be needed which would
> disassemble the generator; apply f to the the list [a b ..];
> reassemble the generator; and push the new value on the stack.

Yup. It's a simple enough function to define.

The hard part is building all of the 'f's you might need. It's
impossible to build them all; in general you have to let programmers
build 'em for you. Icon takes one route (by making expressions be
capable of repeating themselves); anyone know any others?

> Don Groves

-Billy