error-handling

Typed errors in Effect are modeled using Data.TaggedError to define domain failures that travel in the error channel. You handle these errors using catchTag, catchTags, and catchAll for principled, exhaustible pattern matching.

Error-channel failures in Effect are expected, typed domain errors caught via catchTag or catchAll, whereas defects are unexpected failures outside the error channel. mapError transforms error-channel types, leaving defects isolated.

Use catchTag to intercept and handle a specific tagged error from an Effect's error channel, and use catchTags to handle multiple tagged errors simultaneously, ensuring exhaustible recovery across domain failures.

Yes, mapError transforms the error channel type in Effect. It is applied to compose error transformations and establish clear error boundaries across different application layers.

Yes, this approach is designed for functional TypeScript applications using Effect. It enables robust error handling, structured recovery, and clear error boundary semantics without relying on traditional try/catch blocks.