Regression in type-checking `for*/list` forms when annotation is not directly in the form
Open
Nobody has claimed this yet.
- Dominant language
- Racket
- Stars
- 575
- Forks
- 106
- Avg merge
- 2h 1m
- Merged PRs (30d)
- 2
Description
(Sorry to discover this a bit late. I hope it's not a release blocker. It's not a problem for me if nobody else incurs it)
What version of Racket are you using?
v6.10.0.1
What program did you run?
#lang typed/racket/base
(define ns : (Listof Number)
(for*/list ([n '(1 2 3)]
[m '(4 5)])
42))
What should have happened?
Program type checks as in v6.9.0.4
If you got an error message, please include it here.
; Type Checker: Error in macro expansion -- insufficient type information to typecheck. please add more type annotations
; in: (for*/list ((n (quote (1 2 3))) (m (quote (4 5)))) 42)
If I move the annotation to inside the for*/list form, it typechecks as expected:
#lang typed/racket/base
(define ns
(for*/list : (Listof Number) ([n '(1 2 3)]
[m '(4 5)])
42))
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
No files or tests are named. Run the supplied typed/racket/base program under v6.10.0.1 and v6.9.0.4, then trace the for*/list type-checking and macro-expansion path. Done means the outer Listof Number annotation type-checks as it did in v6.9.0.4.
Written by the indexing model from the issue text.
Assessment
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100