new map type (Re: Ann: SWI-Prolog 7.1.0)

  - The system introduces `maps' as primary citizens.  Maps are

    collections of key-value pairs, optionally typed. Maps are
    supported by read and write.  The syntax is

    type{key1:value1, key2:value2, ...}


This will be very nice.  Incidentally in my project I have compiled 
names into indices in class-generated objects, so I won't be needing
the map for that.
    Keys in a map can be addressed using the functional notation
    Map.Key.  User functions on maps can be accessed as Map.Compound
    (e.g., Vector.multiply(V2)).


When you say functional notation, I am a little leary of confusion

regarding when something gets applied:
plus(Map.key, 2,3) does this work?
plus(Map.Key, 2,3) does this work?  Does it backtrack if Key is non-ground?

The notation Vector.multiply(V2) *might* be okay, but I'm skeptical.  I 
suppose this implies:
Vector  .multiply(V2) % good
Vector.  multiply(V2) % error

But in any event, is there a meaning to this example, or is it a bad choice 
of words?  The only thing I can think of is not very Prolog-like:

V2 = V1.scalar_multiply(3), or
Number = Vector.dotProduct(V2)


Will/do other systems support maps?

 
Alan Baljeu