Record/list indexing

[foxfriends]

It would be convenient to be able to access fields of a record similarly to in regular languages.

Having to use destructuring for everything is very verbose:

fullName(person { firstName: FirstName, lastName: LastName }, FullName) :-
  FullName <- FirstName + " " + LastName.

Where using field access could be simpler:

fullName(person(P), FullName) :-
  FullName <- P{firstName} + " " + P{lastName}.

This indexing operation would be not tied to variables, so a bit less useful but valid:

fullName(FullName) :-
  FullName <- { firstName: "Cam" }{firstName} + " " + { lastName: "Eldridge" }{lastName}.

Would also be useful to have a similar array access:

firstAndLastName(Names, FullName) :- 
  len(Names, N),
  FullName <- Names[0] + " " + Names[N - 1].

Could even chain accessors:

Record{field}[3]{anotherField}{lastField}

Wildcards/variables in records would be bound as usual:

name(Name, person(P)) :- 
  equal(P{name}, Name).

name("Cam", person { name: A }).
// A = "Cam"

[foxfriends]

I am noticing that we don't really need indexing or updating, what we need is language level support for views

1. Get a value at an path
2. Set a value at a path
3. Transform the value at a path

I do (3) very often (destructure a struct, transform a value, reconstruct it), so it would be nice to make all these steps super painless.

Views are a very functional-programming type idea though... maybe what I am doing is actually just something that needs a functional language...