Scheme Programming Language :: how do I support "delay" in my interpreter without breaking my back?


	how do I support "delay" in my interpreter without breaking my back? hi how do I support "delay" in my interpreter without breaking my back? dillog@gmail.com writes: > how do I support "delay" in my interpreter without breaking my back? Copy R5RS example implementation. It's in section 6.4 under "force", but the entry for "delay" does point there. On Apr 2, 2:08 pm, Jussi Piitulainen <jpiit@ling.helsinki.fi> wrote: > dillog@gmail.com writes: > > how do I support "delay" in my interpreter without breaking my back? > Copy R5RS example implementation. It's in section 6.4 under "force", > but the entry for "delay" does point there. I just need to figure out where to put a case statement for it, under MC-eval or MC-apply? I'm having a tough time figuring out which or both. dillog@gmail.com writes: > Jussi Piitulainen wrote: >> dillog@gmail.com writes: >>> how do I support "delay" in my interpreter without breaking my >>> back? >> Copy R5RS example implementation. It's in section 6.4 under >> "force", but the entry for "delay" does point there. > I just need to figure out where to put a case statement for it, > under MC-eval or MC-apply? I'm having a tough time figuring out > which or both. Where do you deal with "let" and "do"? That should be the place. Without macro expansion, I'd expect eval to dispatch to a clause where it is known that the expression at hand is a (delay expression), then construct the (lambda () expression) and pass that to apply to be passed to make-promise. On Apr 2, 3:01 pm, Jussi Piitulainen <jpiit@ling.helsinki.fi> wrote: - Hide quoted text - > dillog@gmail.com writes: > > Jussi Piitulainen wrote: > >> dillog@gmail.com writes: > >>> how do I support "delay" in my interpreter without breaking my > >>> back? > >> Copy R5RS example implementation. It's in section 6.4 under > >> "force", but the entry for "delay" does point there. > > I just need to figure out where to put a case statement for it, > > under MC-eval or MC-apply? I'm having a tough time figuring out > > which or both. > Where do you deal with "let" and "do"? That should be the place. > Without macro expansion, I'd expect eval to dispatch to a clause where > it is known that the expression at hand is a (delay expression), then > construct the (lambda () expression) and pass that to apply to be > passed to make-promise. I turns out one case statement under mc-eval will do it. thanks. it looks almost like lambda :)