map4<A, A2 extends A, B, B2 extends B, C, C2 extends C, D, D2 extends D, E> static method

Option<E> map4<A, A2 extends A, B, B2 extends B, C, C2 extends C, D, D2 extends D, E>(
  1. Option<A2> fa,
  2. Option<B2> fb,
  3. Option<C2> fc,
  4. Option<D2> fd,
  5. E fun(
    1. A a,
    2. B b,
    3. C c,
    4. D d,
    ),
)

Implementation

static Option<E> map4<A, A2 extends A, B, B2 extends B, C, C2 extends C, D, D2 extends D, E>(Option<A2> fa, Option<B2> fb, Option<C2> fc, Option<D2> fd, E fun(A a, B b, C c, D d)) =>
  fa.fold(none, (a) => fb.fold(none, (b) => fc.fold(none, (c) => fd.fold(none, (d) => some(fun(a, b, c, d))))));