EffectTalk

Defining typed errors with Data.TaggedError

Use `Data.TaggedError` to define your own typed error types. Tagged errors carry a `_tag` for pattern matching and can hold structured data (e.g. `userId`, `message`).

Unlike plain strings or `Error`, tagged errors are explicit in the type system and work with `catchTag`.

  • Use `class X extends Data.TaggedError("TagName")<{ fields }> {}`
  • The `_tag` enables `catchTag("TagName", ...)`
  • Add fields (e.g. `message`, `code`) for context
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