Generate permutations of Boolean values

java_8_boolean_permutation.java

Stream.of(true, false)
    .map(b2 -> Stream.of(true, false)
        .map(b3 -> List.of(b2, b3))
        .collect(Collectors.toList()))
    .flatMap(Collection::stream)
    .collect(Collectors.toList());
// [[true, true], [true, false], [false, true], [false, false]]
 

Stream.of(true, false)
    .map(b1 -> Stream.of(true, false)
        .map(b2 -> Stream.of(true, false)
            .map(b3 -> List.of(b1, b2, b3)
            .collect(Collectors.toList()))
        .flatMap(Collection::stream)
        .collect(Collectors.toList()))
    .flatMap(Collection::stream)
    .collect(Collectors.toList());
//  [[true, true, true], [true, true, false], [true, false, true], [true, false, false], [false, true, true], [false, true, false], [false, false, true], [false, false, false]]