Assignment and auto-deref
=========================

Cases:

    pN: N pointers deep

    int <- int          lvalue <- direct
    p1  <- int          direct <- direct

    p1  <- p1           lvalue <- direct  (assigning pointer)
    p1  <- p1           direct <- deref   (assigning target value)


Syntax comparisons:

    In C:           In Pascal
    p = p           p := p
    *p = *p         p^ := p^


    Syntax 1            Syntax 2            Syntax 3            Syntax 4
    p ref = p ref       p = p               
    p.value = p.value   p^ = p^             

    Syntax 2 could be combined with auto-dereferencing only when the expr is
    not E.field, E.method(...) or E[...].

    It is still possible to use call-site qualifiers (var/aliased/arena/own...)
    this.do_stuff(var x, own y)
    ????

    What about the object itself?
    Re-introduce sigills, but use them everywhere?

    ! = var, @ = arena, $ = own         (but @ conflicts with address of, unless & is used instead)
    ?? = aliased, ?? = threaded, ?? = writeonly, ?? = out, ...
    !ref int p

    Using sigills for var and arena is simple:
    this.do_stuff()
    this.do_stuff!()
    this.do_stuff@()
    this.do_stuff@!()

    Should reference specifiers appear at the call-site also?


Also:

    Change assignment operator to  <-   ?

        int x = 1
        var int y
        y <- 2
        if x == y {
        }