racket / racket/htdp

Stepper doesn't show steps for some programs

Open
#20 9 comments 0 reactions 1 assignee View on GitHub

@jbclements is already working on this.

Since Jun 25, 2017.

stepper
Dominant language
Racket
Stars
112
Forks
73
Avg merge
9h 41m
Merged PRs (30d)
1

Description

In the stepper for "Intermediate Student with lambda", the program:

((lambda (x) (x x)) (lambda (x) (x x)))

doesn't show any steps, even though this program takes infinitely many evaluation steps. The stepper appears to run forever without finding the first step.

On the other hand, the program:

((lambda (x) (x x)) (lambda (x) ((x x) (x x))))

shows infinitely many steps like it should.

(This behavior seems to be sensitive to alpha-renaming, so my guess at a cause is that the stepper is suppressing steps that yield a syntactically identical program.)

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.