It also isn't one when "looking at it with the eyes of CS knowledge", given that Common Lisp has very powerful support for OO and procedural programming out of the box, and in order to most effectively use an FP style it's necessary to rely on community developed libraries...
The issue's that Schemes (and Clojure) are way more functional than Common Lisp and e.g. `funcall` feels like a kludge compared to lisp-1. If you read the old CL codebases or modern code, destructive and imperative use are common, so it doesn't feel terribly revisionist (just compared to pascal, c, bliss etc.).
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.
Having the data structures is nice and all, but using them is kind of painful. They are certainly second class.
Having to use accessor functions or destructuring macros instead of just a period or -> is often annoying too. The lack of syntax has cons as well as pros.
Writing a reader macro that allows for something like...
[some-numbers 0]
...to get the first (many programming languages make this mistake, using 0 to refer to the first element of a collection, so we can forgive CL for this) element. But I'm curious how you can write...
(object -> slot)
...without getting an error about OBJECT not being a valid function or macro.
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.
Yes, but the various Lisps that Common Lisp is the more-or-less common subset of are (were?) all 0-indexed. Between easy heap implementation (left is (ash index 1), right is (1+ (ash index 1)), parent is (ash index -1)) and easy last element selection (nth seq (length seq)) I prefer 1-indexing, but I realize that's an unpopular opinion.
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:
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).
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.
As someone who's dabbled with Scheme, Clojure, and CL long ago and started wanting to get back into CL, I really enjoyed that course as a combination refresher plus deep dive into some topics I didn't really know before (including CLOS).
My main takeaway was multi-methods, they didn't really click for me before I started seriously digging into CLOS. I wish more languages supported them/played around with similar ideas.