Warn when the penultimate guard is a not
Open
Nobody has claimed this yet.
- Dominant language
- Haskell
- Stars
- 1.6k
- Forks
- 210
- PR merge metrics
- No merged PRs in 30d
Description
When the last guard before an otherwise is wrapped in a not, we should recommend that they be swapped to avoid the not. For example, this:
f x
| x < 2 = doSpecial x
| not (isPrime x) = doComposite x
| otherwise = doPrime x
Should become this:
f x
| x < 2 = doSpecial x
| isPrime x = doPrime x
| otherwise = doComposite x
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
Start by locating HLint's guard-suggestion logic and the tests covering guards followed by an otherwise branch; the issue does not name specific files or entry points. Add coverage for a penultimate guard wrapped in not, and verify the suggestion swaps the branches while preserving the shown behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- haskell
- Domain
- tooling
- Issue type
- Feature
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100