whenIsRightOtherwise

Applies one callback on Right values and a second callback on every non-Right value.

Interactive example

Syntax

Classic signature

function whenIsRightOtherwise<
  GenericInput extends unknown,
  GenericOutputRight,
  GenericOutputOtherwise
>(
  input: GenericInput,
  theFunction: (value: Unwrap<Extract<GenericInput, Right>>) => GenericOutputRight,
  otherwiseFunction: (value: Extract<GenericInput, Left> | Exclude<GenericInput, Right | Left>) => GenericOutputOtherwise
): GenericOutputRight | GenericOutputOtherwise;

Curried signature

function whenIsRightOtherwise<
  GenericInput extends unknown,
  GenericOutputRight,
  GenericOutputOtherwise
>(
  theFunction: (value: Unwrap<Extract<GenericInput, Right>>) => GenericOutputRight,
  otherwiseFunction: (value: Extract<GenericInput, Left> | Exclude<GenericInput, Right | Left>) => GenericOutputOtherwise
): (input: GenericInput) => GenericOutputRight | GenericOutputOtherwise;

Parameters

• theFunction: Callback executed when input is Right (receives unwrapped payload).
• otherwiseFunction: Callback executed for remaining values (Left or non-Either), without unwrap.
• input: Value to process immediately (optional in curried style).

Return value

Returns the result of theFunction for Right, otherwise the result of otherwiseFunction.

See also

• whenIsLeftOtherwise - Symmetric variant for Left.
• whenIsRight - Right-only mapping without explicit otherwise.