Smaller dot application hints
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- Dominant language
- Haskell
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Description
From https://code.google.com/p/ndmitchell/issues/detail?id=570:
Given:
boo = map f . map g . z
HLint suggests:
Sample.hs:5:7: Warning: Use map once
Found:
map f . map g . z
Why not:
map (f . g) . z
The . z at the end is correct, but a little inelegant. This is added because of the associativity of (.). One possible "quick fix" would be to change (.) to associate the other way round, since it is associative anyway - not sure if that would break anything though.
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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 source files or tests are named. Reproduce the HLint warning using the provided map f . map g . z example, then trace the hint that rewrites chained map applications. Done means the suggestion avoids the inelegant trailing . z while preserving the intended transformation.
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
- 35/100