[js8]

Personally, I grew beyond this. I tried Common Lisp, Forth and Haskell. I enjoyed books On Lisp and Let Over Lambda.

Now I think the best programming language is Barry Jay's Triage Calculus, which is close to combinatory logic or untyped lambda calculus.

But unlike lambda calculus (which is easily expressed in TC), triage calculus has a built-in quoting and introspection (similar to Lisp's CAR and CDR), which lets you easily add typechecking. So in TC, you can have any syntax you want, just by building the correct abstraction. It's truly an ultimate programming language.

TC shows that there is a false dichotomy between programming language features and syntax on one hand, and the function/API definitions in the standard library or user code on the other hand. Every time you write a piece of code intended to be reusable, you're adding to the language. It can all be expressed as some term in TC.

All the syntactic squibbles are a matter of habit. Although one syntactic feature you really want in TC is the let over lambda abstraction, because it's somewhat annoying to order combinators by hand.

[wild_egg]

Do you mean Tree Calculus? https://treecalcul.us

[js8]

Yes, although I wish he would call it properly triage calculus (see https://treecalcul.us/specification/), because although the languages are almost identical in power, the original tree calculus and triage calculus rules lead to different programs.