Add Effect.transposeMapOption

[LaureRC]

Type

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update

Description

Add Effect.traverseOption. Today in our codebase we're using a helper to do that, but I really think it would be a nice addition that would be useful to others.

I'm aware that we could use the Effect.transposeOption:

pipe(
  Effect.succeed(Option.some('value')), 
  Effect.map(Option.map(someEffectfulOperation)), 
  Effect.flatMap(Effect.transposeOption)
)

But this is simpler and more relevant for all the use cases where I need it in my work:

pipe(
  Effect.succeed(Option.some('value')),
  Effect.flatMap(Effect.traverseOption(someEffectfulOperation))
)

So I'd still push for this addition, hence my move to try to open a PR for it! :)

For the naming of this method, in our codebase we used optionTraverseEffect but given the discussions in issue #3142, it seems that adding this method in the Effect module and using the term traverse would be the way to go.
Also, if you agree with this addition and have ideas on improving the documentation part of this feature I'm interested as I'm not fully happy with my final version.

Related

• Related Issue Option.mapEffect #3142
• Closes Option.mapEffect #3142

[changeset-bot]

🦋 Changeset detected

Latest commit: 31acdef

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 36 packages

Name	Type
effect	Minor
@effect/cli	Major
@effect/cluster-browser	Major
@effect/cluster-node	Major
@effect/cluster-workflow	Major
@effect/cluster	Major
@effect/experimental	Major
@effect/opentelemetry	Major
@effect/platform-browser	Major
@effect/platform-bun	Major
@effect/platform-node-shared	Major
@effect/platform-node	Major
@effect/platform	Major
@effect/printer-ansi	Major
@effect/printer	Major
@effect/rpc-http	Major
@effect/rpc	Major
@effect/sql-clickhouse	Major
@effect/sql-d1	Major
@effect/sql-drizzle	Major
@effect/sql-kysely	Major
@effect/sql-libsql	Major
@effect/sql-mssql	Major
@effect/sql-mysql2	Major
@effect/sql-pg	Major
@effect/sql-sqlite-bun	Major
@effect/sql-sqlite-do	Major
@effect/sql-sqlite-node	Major
@effect/sql-sqlite-react-native	Major
@effect/sql-sqlite-wasm	Major
@effect/sql	Major
@effect/typeclass	Major
@effect/vitest	Major
@effect/ai	Major
@effect/ai-anthropic	Major
@effect/ai-openai	Major

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[gcanti]

I would go with Effect.transposeMapOption as it follows the same pattern as filterMap: applying map first, then transpose, just like filterMap applies map first, then filter. Additionally, both APIs would appear when you start typing transpo....

[LaureRC]

I would go with Effect.transposeMapOption as it follows the same pattern as filterMap: applying map first, then transpose, just like filterMap applies map first, then filter. Additionally, both APIs would appear when you start typing transpo....

I completely agree with your points so I pushed a new commit to use that naming :)

And nice catch on the documentation example, sorry for that! It's now fixed!