[Sam]
> ...
> Except that since the escape procedure is 'first-class' it can be
> stored away and invoked (and reinvoked) later. [that's all that
> 'first-class' means: a thing that can be stored in a variable,
> returned from a function, used as an argument, etc..]
>
> I've never seen a let/cc that wasn't full-blown, but it wouldn't
> surprise me.
The let/cc's in question were specifically defined to create continuations
valid only during let/cc's dynamic extent, so that, sure, you could store
them away, but trying to invoke one later could be an error. It's in that
sense I meant they weren't "first class".
Other flavors of Scheme appear to call this concept "weak continuation", and
use a different verb to invoke it (like call-with-escaping-continuation, or
call/ec). Suspect the let/cc oddballs I found were simply confused
implementations (there are a lot of amateur Scheme implementations out
there!).
>> Would full-blown coroutines be powerful enough for your needs?
> Yes, I think they would be. But I think with Python it's going to
> be just about as hard, either way.
Most people on this list are comfortable with coroutines already because
they already understand them -- Jeremy can even reach across the hall and
hand Guido a helpful book <wink>. So pondering coroutines increase the
number of brain cells willing to think about the implementation.
continuation-examples-leave-people-still-going-"huh?"-after-an-
hour-of-explanation-ly y'rs - tim
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4