fold<B> method

B fold<B>(
  1. B onNone(),
  2. B onSome(
    1. T t
    )
)

Execute onSome when value is Some, otherwise execute onNone.

[🍌].fold(() => 🍎, (🍌) => 🍌 * 2) -> 🍌🍌
[_].fold(() => 🍎, (🍌) => 🍌 * 2) -> 🍎

Same as match.

Implementation

B fold<B>(B Function() onNone, B Function(T t) onSome) =>
    match(onNone, onSome);