Usage examples

Match(10).option(
    Case(x -> x > 10, x -> x + " is larger than 10"),
    Case(x -> x < 10, x -> x + " is smaller than 10"),
    Case($(10), x -> x + " is 10"),
    Default(x -> x + " is stranger than we thought")
);

• The first parameter of Case gets a predicate to match the match value with.
• The second parameter of Case has two options: a literal value, or a mapper for the match value.
• Default case works like Scalas case _.
• $ sign is a utility function that creates a predicate which matches the match value to a given literal.

Match(LocalDate.now()).of(
    Case(date -> date.isAfter(LocalDate.now()), "its later then now"),
    Case(date -> date.isBefore(LocalDate.now()), "its before now"),
    Case(instanceOf(Date.class), "its a local date"),
    Case($(LocalDate.now()), "its today"),
    Default("somethings wrong")
    Default("somethings wrong 2")
);

• instanceOf is a built-in utility function that creates a predicate.
• When two Default cases will be written, a warning will be printed to stdout.

Match(Optional.of(5)).of(
    Case($d($(4)), "it holds 4"),
    Case($d($(5)), "it holds 5"),
    Default(x -> x + "some optional")
);

• $d is a "destructure" method that allows to "map" over classes which have wrappers with a get method, like Optional. It receives a Predicate<(innerValue)>, extracts the inner value and applies the predicate on it.