How do I fix the error with my coroutine initialization?

Help with Snap! Snap! Editor
1

error highlighted in red
error highlighted in red596×512 56.3 KB

untitled script pic(6)
untitled script pic(6)369×155 34.1 KB

2

In procedure YIELD, you refer to a variable COROUTINE that doesn’t exist in this scope.

offtopic, for @jens

See, this is why Logo uses dynamic scope. If Snap! were dynamically scoped, it would’ve done what they mean. :~)

3
Offtopic

Quick&dirty dynamic scope variable getter

coroutine script pic (2)
coroutine script pic (2)918×508 110 KB

Used to obtain variables traversing the call stack

coroutine script pic (3)
coroutine script pic (3)1058×208 48.4 KB

But, I’m not sure if it’s a way to go…

The OP already scan a call stack to get parent with ...
It’s a problem with the general concept. The “yield” should be a method of a given coroutine and be bound to that object.
Or be called with live coroutine as a parameter
Or something like this to refer to enclosing lexical scope should be invented.

There is untitled script pic (7) from the Metaprogramming library

BTW: () of () may have predefined selectors for common this caller, script

4

might i ask, what is this project for? i see a “lua corutine from ring” block, but i want to know what exactly you’re making

5

I just felt like making a script that can pause itself using continuations

6

so, like, you call the coroutine and then you can pause it if you need to, midway?
i actually have some experience in lua, but i havent tried coroutines as of yet, i havent had a real need for them in any of my projects.

7

yes, the coroutine can pause.

btw, by interruptible I meant can pause

8

Quick&dirty dynamic scope variable getter

My point wasn’t to suggest that the OP invent dynamic scope. I was trying to convince Jens (really just for him!) why it was a good idea for Logo to use dynamic scope even though lexical scope is the official right thing; kids’ expectations generally are that if a variable exists, it’s in scope. That’s why the OP didn’t understand the error message; “if a variable exists, it’s in scope” really is much more natural than the other way.

9

scope is hard, not just for beginners. Which is - I guess - one of the raisons d`être for OOP. Come to think of it, OOP sorta does offer a wacky form of dynamic scope…

10

I fixed it, I forgot to recurse

coroutine madness script pic
coroutine madness script pic414×284 49.8 KB

11

Come to think of it, OOP sorta does offer a wacky form of dynamic scope…

Could you expand on this? I don’t know what you mean. Tnx.