The context of this email is the proposal by Matthew Flatt that we move to an easier-to-accept surface syntax for #lang racket2.
Matthew Flatt has heard more than enough from me of concern about this proposal. But I should indicate that I'm highly sympathetic to the goal. I would like to lay out the following observations: - The challenge with s-expressions is largely in anxiety with something that looks extremely alien. I suspect there's more fear from instructors than students in encountering a lisp syntax; my experience is that introducing someone who doesn't know differently to a parenthetical syntax isn't scary for them, and they tend to like it. But people who have *started out* with experience in a non-lispy language tend to find it scary. - Nonetheless, assumptions that various math operators should be infix is understandable because that's what people see today. - I am indeed very for growth in the community, though my main interest in growth is in seeing a wider diversity of participants than just raw numbers. Obviously other peoples' mileage may vary. - We are at serious risk in this pivot of losing some key things: - Many communities I have been in that have undertaken such a large pivot to increase popularity expend enormous energy in the move to the new thing, and in that process, the project actually collapses. What I'm trying to say is that a pivot is a gamble; we should calculate our odds carefully. (Indeed, the first thing I thought when I heard that this might happen was, did I make a mistake in shifting my work to Racket? It is unlikely I would have come to Racket if there wasn't an equivalent amount of elegance.) - I'm not sure if I could have understood Racket Week with a syntax that didn't have the elegance of s-expressions. This is not to say that *no* syntax can have that level of elegance where things can be so clear, however. IIRC Matthew's proposal for "#lang racket2" was something like the following: a) function(args ...) should work. b) infix is necessary for math, such as 3 + 4 c) parentheses should be possible for grouping The weird thing about the last one being that this is already kind of true in s-expressions, but by ~default this also results in application. Let me add one more suggested design goal: - the new syntax should must not be significantly less elegant than s-expressions. Is there a way to achieve this? I actually think the best path forward is to have a surface syntax that actually maps completely to s-expressions, which is in fact universal that it can work with *any* s-expression syntax. I would suggest starting with Wisp as the basis for examining this: https://dustycloud.org/blog/wisp-lisp-alternative/ https://srfi.schemers.org/srfi-119/srfi-119.html Sweet-expressions may also be an alternative to explore. However, I think Wisp is a more elegant base; it can transform *any* wisp code into s-exp code. Not discussed in my blogpost about Wisp is that it also supports infix via {3 + 4}. So ok, now we have that. And we can still group: {3 + {8 + 4}} So that's points b) and c), but we don't have a) yet. Could we add it? I think we can extend wisp with one thing and get everything we want: if you have func(arg1 arg2 arg3) where the parenthesis comes *immediately* after the symbol, that is rewritten to (func arg1 arg2 arg3). I will call this version ~Wisp. With all this, observe the following code rewritten from Scheme to ~Wisp: (define (rgb-maker mk) (lambda (sz) (vc-append (colorize (mk sz) "red") (colorize (mk sz) "green") (colorize (mk sz) "blue")))) define rgb-maker(mk) lambda(sz) vc-append(colorize(mk(sz) "red") colorize(mk(sz) "green") colorize(mk(sz) "blue")) Here is another chunk of code, taken from HTdP2: (and (or (= (string-length "hello world") (string->number "11")) (string=? "hello world" "good morning")) (>= (+ (string-length "hello world") 60) 80)) To: and(or({string-length("hello world") = string->number("11")} string=?("hello world" "good morning")) {{(string-length "hello world") + 60} >= 80}) And in fact the latter can transform itself *directly* into the former. And the former technically is also still valid Wisp: you can embed s-expressions into it and they still work. I think this satisfies the requirements that Matthew laid out. There's another major advantage of this. We can now write languages that work either like: #lang s-exp "mylang.rkt" or: #lang wisp "mylang.rkt" The main thing that Wisp is missing right now is editor tooling so that doing indentation is convenient. But that's more than feasible to add, imo. I think this is the best way to move forward without creating significant divisions, throwing out valuable things we have, or making future Racket Week courses all that much harder. What do people think? - Chris -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/87wogkqzo0.fsf%40dustycloud.org. For more options, visit https://groups.google.com/d/optout.