fp-types-ref

Choosing the right fp-ts type in TypeScript requires evaluating whether your workflow is synchronous or asynchronous and whether it involves nullable values or recoverable errors. This guides you to select Option, Either, or Task based on those specific data-handling conditions.

Use Task in fp-ts for asynchronous operations instead of Either when dealing with lazy asynchronous computations that do not inherently fail with recoverable errors. Task handles async workflows, whereas Either is meant for synchronous error handling.

The difference between Option and Either in functional TypeScript is that Option represents a nullable value or the absence of a value, while Either represents a computation that can fail and return an error. This skill maps your specific data scenario to the correct structure.

To import fp-ts modules for mapping over Option or Task structures, you can use the quick import patterns provided by this skill. It offers actionable guidance on the correct module paths for common fp-ts structures to quickly apply functional operations.

You do not need external tooling to decide between fp-ts types for a nullable API response. This skill provides quick, actionable guidance and a concise decision tree to help you choose the appropriate type without requiring any external dependencies.