Using in-range directly in a for loop uses less specific types
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- Dominant language
- Racket
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- 575
- Forks
- 106
- Avg merge
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- Merged PRs (30d)
- 2
Description
Typechecks:
(define lst : (Listof Nonnegative-Fixnum)
(let ([r (in-range 10)])
(for/list ([i : Nonnegative-Fixnum r])
i)))
Does not typecheck:
(define lst : (Listof Nonnegative-Fixnum)
(for/list ([i : Nonnegative-Fixnum (in-range 10)])
i))
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Research direction
Reproduce the two Typed Racket snippets in the issue and compare their typechecking results. The fix is complete when using in-range directly in the for/list binding accepts Nonnegative-Fixnum as the intermediate binding type, matching the separately bound example.
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
- 42/100