Functional Programming in React

Practical patterns for React apps. Untested integration sketches; decode external data and verify lifecycle behavior.

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Detailed Guide

Read the detailed guide before executing this skill. It retains the complete procedure and reference material. Treat its safety, prerequisites, and validation requirements as mandatory. For focused work, load the relevant sections; for end-to-end work, read the guide completely.

When to Use What

| Situation | Use | |-----------|-----| | Value might not exist | Option<T> | | Operation might fail (sync) | Either<E, A> | | Async operation might fail | TaskEither<E, A> | | Need loading/error/success UI | RemoteData<E, A> | | Form with multiple validations | Either with validation applicative | | Dependency injection | Context + ReaderTaskEither | | Prevent re-renders with fp-ts | useMemo or fp-ts-react-stable-hooks |

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Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.