List.member on Dict.keys/Set.toList -> Dict/Set.member · jfmengels/elm-review-simplify#290

2024-02-24T12:17:09.000Z

**What the rule should do:** Replace List.member on Set.toList/Dict.keys with Set/Dict.member **What problems does it solve:** Simplifying and optimizes unnecessary convertions **Example of things the rule would report:** ```elm List.member c (Dict.keys d) --> Dict.member c d ``` ```elm List.member c (Set.toList d) --> Set.member c d ``` **Example of things the rule would not report:** Since Set/Dict.member requires comparable, but List.member does not, applying this replacement to Set/Dict.empty, could lead to a type error. So therefore we should/could not replace it in that case. (But it should be caught by some other simplification rule) ```elm List.member c (Dict.keys Dict.empty) ``` The above should be simplified to `False` anyways, by the callOnEmptyReturnsCheck **Should this be part of the Simplify rule or should it be a new rule?** Part of Simplify **I am looking for:** - Feedback

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enhancementhelp wanted

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Description

What the rule should do: Replace List.member on Set.toList/Dict.keys with Set/Dict.member

What problems does it solve: Simplifying and optimizes unnecessary convertions

Example of things the rule would report:

List.member c (Dict.keys d)
--> Dict.member c d

List.member c (Set.toList d)
--> Set.member c d

Example of things the rule would not report: Since Set/Dict.member requires comparable, but List.member does not, applying this replacement to Set/Dict.empty, could lead to a type error. So therefore we should/could not replace it in that case. (But it should be caught by some other simplification rule)

List.member c (Dict.keys Dict.empty)

The above should be simplified to False anyways, by the callOnEmptyReturnsCheck

Should this be part of the Simplify rule or should it be a new rule?

Part of Simplify

I am looking for:

Feedback

Contributor guide

Research direction: Examine the existing Simplify rule, especially how it handles type information and the callOnEmptyReturnsCheck function. Determine if the types of arguments can be inferred statically to avoid replacing when the dictionary/set is empty. Implement the new simplification case.
Tech stack: None
Domain: toolingdeveloper experience
Issue type: Feature
Difficulty: 2
Estimated time: Half day
Activity status: Active
Clarity: Clear
Prerequisites: Elmelm reviewGit
Newbie friendliness: 65

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Description

Contributor guide

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