isErr

isErr<E, A>(state): state is Err<E>

Defined in: Core/Op.ts:623

Returns true if the state is Err (the operation failed with a typed error).

Type Parameters

E

E

A

A

Parameters

state

State<E, A>

Returns

state is Err<E>

Example

manager.subscribe(state => {
  if (Op.isErr(state)) showError(state.error);
});