Map type

[dmfs]

A simple immutable map type. Interface is tbd.

[dmfs]

Initial idea for the interface design:

public interface Map<Key, Value> extends Function<Key, Optional<Value>>, Set<Key>, Iterable<Pair<Key, Value>> {
    // returns the number of key value pairs in this map
    public int size();
}

[dmfs]

On a second though, we probably don't need the Set interface:

public interface Map<Key, Value> extends Function<Key, Optional<Value>>, Iterable<Pair<Key, Value>> {
    // returns the number of key value pairs in this map
    public int size();
}

If a Set is needed, it could be created like so:

Set<Key> keySet = new KeySet<>(map);