A function which derives its input from a delegate function which is invoked based on the result of a given predicate. This is the object oriented version of a switch expression. Unlike a switch expression though, it can take any predicate of the switched type. The downside is we can't enforce the expression to be exhaustive.
This is a simple example of how it would be used
Function<String,String> f = new Switch<>(
new Case<>(String::isEmpty, s -> "the String was empty"),
new Case<>(s -> s.length() == 1, s -> s + " contains a single character"),
new Default<>(s -> s + " is " + s.length + " characters long"));
If no case matches an IllegalArgumentException is thrown.
The names Switch, Case and Default are not carved in stone. Other names like Case, When and Else might work too (e.g. Ruby style).
A function which derives its input from a delegate function which is invoked based on the result of a given predicate. This is the object oriented version of a switch expression. Unlike a switch expression though, it can take any predicate of the switched type. The downside is we can't enforce the expression to be exhaustive.
This is a simple example of how it would be used
If no case matches an
IllegalArgumentExceptionis thrown.The names
Switch,CaseandDefaultare not carved in stone. Other names likeCase,WhenandElsemight work too (e.g. Ruby style).