What FP style? Haskell style, I guess.

When I learnt Lisp, Lisp and Scheme were FP, Miranda was still around, and Caml Light had just started being known outside INRIA.

I really dislike revisionism regarding what it means to be FP.

A computing literature classic.

https://en.m.wikipedia.org/wiki/The_Art_of_the_Metaobject_Pr...

> so we can forgive CL for this

The 1962 dated Lisp 1.5 Programmer's Manual already describes a 0 based array feature. Lisp was clearly one of the historic instigators of zero based array, rather than just playing along.

A late reply but it's worth addressing one way of doing this. First, your concern about object not being a valid function or macro isn't relevant at read time. Second, note that Lisp already has similar syntax: '(1 . 2) is essentially (cons 1 2). Implementing this type of syntax is not a privilege of the implementation alone. You're allowed to redefine your own reader for left paren. In SBCL:

    CL-USER> (get-macro-character #\()
    SB-IMPL::READ-LIST

You can write `(set-macro-character #\( 'sb-impl::read-list)` and everything continues to work just fine. You can also jump-to-source and modify it if you want -- though it's cleaner to just copy it out to your own project, that's what I did for a quick hack/proof of concept. Essentially I added before the existing (when...) which handles the special dot syntax:

      (when (and (eq firstchar #\-)
                 (eq (peek-char t stream t nil t) #\>))
        (read-char stream t) ; actually read the nextchar > to discard it
        (let ((next-obj (read stream)))
          (sb-impl::flush-whitespace stream rt)
          (return `(slot-value ,@listtail ',next-obj))))

I won't claim this is good or proper, but it shows that it's quite feasible. We've turned (foo -> bar) into (slot-value foo 'bar).

    CL-USER> (defclass vec2 ()
      ((x :initarg :x)
       (y :initarg :y)))
    #<STANDARD-CLASS COMMON-LISP-USER::VEC2>
    CL-USER> (defparameter vec (make-instance 'vec2 :x 3 :y 4))
    VEC
    CL-USER> (vec -> y)
    4
    CL-USER> (read-from-string "(print (vec -> x))")
    (PRINT (SLOT-VALUE VEC 'X))
    18

Personally I wouldn't use this even if it was more properly/carefully implemented. (There's really no reason to replace the default left-paren reader, and no reason we have to have a space surrounding the "->". One thing I like about the infix reader macro package https://github.com/quil-lang/cmu-infix is that it doesn't care about spaces, I can write #I(1+1 + 4) and get 6.) I'm quite happy putting my class in its own package, and thus getting the primary tab-completion behavior I care about. e.g. "(ma:<tab>" could complete to "(math:" and then "(math:v<tab>" could complete to a list of options like "vector-x" "vector-y" or so on. I also like the somewhat unusual approach of naming my accessors with a dot prefix, e.g. (.x vec) and (.y vec), or even (math:.x vec) if I haven't imported the symbol.

And also make sure that slot is a symbol in the correct package. Or do like Elisp and do without packages but then have a 16 character prefix

Common Lisp has Lisp in the name, but it is not the same thing. We're talking about languages developed 30 years apart here.

In the 80s, things like immutability just weren't pragmatic due to memory constraints, and CL was designed with pragmatism in mind. Scheme could be argued as FP. Clojure certainly is. CL is not.