Stepper loops on Omega

[jasonhemann]

I wanted to step the following ISL+ program:

#lang htdp/isl+
((λ (x) (x x)) (λ (x) (x x)))

I wanted to try and step through the reduction, and demonstrate it not make progress. But the stepper itself seemed to loop, with a blinking cursor after the End button, and no source displayed. Expected behavior?

Tested on DrRacket, version 9.0, english on an M1 Max running Sonoma.

[mfelleisen]

That's expected. The stepper runs the program to completion and then shows the steps.

[jasonhemann]

Hm. I guess I can imagine why that might be a preferred design.

[rfindler]

Well, you should be able to stop the program with the break button and then get some prefix of the complete set of sets, I would expect. That seems generally useful and totally doable.

[jbclements]

Wait, hang on. The stepper should stop after ~300 steps, and give you a warning dialog. It appears to me that this is not working correctly ATM, this is a bug.