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Consider design change in light of GHC join point work

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#156 38 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
20/100
Issue type
Refactor
Clarity
Needs clarification
Activity status
Stale
Tech stack
haskell
Domain
performance

Research direction

Start by reading the linked join points paper, then inspect the vector implementation's use of Skip and the replicate path mentioned in the issue. Determine whether join point work makes Skip unnecessary and whether removing it restores the suggested optimizations; done requires a justified design conclusion and a confirmed impact on the implementation.

Written by the indexing model from the issue text.

Description

The join points paper suggests that it may now be possible to avoid the need for Skip altogether. It would be worth checking if that's actually the case. If so, it might be possible to simplify the implementation considerably. Furthermore, I seem to recall that the presence of skips (which allow vectors of the same length to be represented by streams of different lengths) prevents one or more optimizations. I vaguely remember trying to do something a bit clever with replicate and finding it impossible because of skips, but I don't remember any details.

Dominant language
Haskell
Stars
401
Forks
145
PR merge metrics
No merged PRs in 30d

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First steps

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  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.

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