Earlier quoted context omitted.
I don't want to reopen this 50+ years old can of worms, but I have 2 questions: 1. Is it about homoiconicity in general or specifically s-expressions [EDIT: I see GP writes about s-exps specifically, missed it at first]? Prolog, Erlang, TCL, and Rebol (just some examples) are homoiconic, but not s-exps based. What do you think about them? 2. Do you often read code without syntax highlighting and proper indentation? A…
1. It's homoiconicity in general. It's most obvious in arithmetic expressions, but homoiconicity (as far as I've seen) eschews semantic indicators besides function name and argument position. I find that keywords and symbols are almost indispensable for smooth eye-parsing of code. 2. No, I use syntax highlighting and indentation all the time. Trying to put words to my vague thoughts, I think the main issue is that, f…
Sure, but that's a totally separate issue from homoiconicity. All the examples I mentioned are infix languages (although TCL requires you to opt-in for that):
https://github.com/adambard/learnxinyminutes-docs/blame/mast... (I couldn't find Rebol, but Red is very similar)
https://github.com/adambard/learnxinyminutes-docs/blame/mast...
https://github.com/adambard/learnxinyminutes-docs/blame/mast...
https://github.com/adambard/learnxinyminutes-docs/blame/mast...
(sorry for the links to blames, but it's impossible to link to a specific line otherwise)
Prolog lets you define your own operators and you have control over associativity and precedence. TCL `expr` works like `$(( 2 + 3 ))` in BASH (which also doesn't support mathematical operators normally) and by reimplementing it you can also add your own operators. Erlang also allows you to define new operators, although it's much more hassle there, as you need to write a parse transform (which is only possible to do so easily because of homoiconicity of the language). I'm not sure about Rebol/Red - I had only passing contact with it long ago.
In other words, homoiconicity itself has little to do with where the "keywords and symbols" are placed in the code, or whether they are used at all.
Accidentally, Lisps also support infix syntax just like TCL: for most Lisps you can grab a lib/package/source of the `infix` macro, which allows you to write infix arithmetic (and code in general) without problems.
> I think the main issue is that, for example, in a let block the only indication of the meaning of all the items is the single function/macro name at the beginning of the block. Whereas in an algol-type language you have assignment operators in each item to indicate what they mean.
Ok, that's one way of looking at this. On the other hand, one can also say that the repeated use of the operator where the meaning of each line is already determined (by the fact that it's inside `let` block) is useless cruft, which actually hinders comprehension by forcing you to mentally parse one element more on every single line of the assignment block. In Lisp, it's actually trivial to extend the language to include this form of `let`:
(let
((a = some_expr) ;; could be `:=` ` ;; in Racket
(cond
[some_condition => a_function_called_on_the_result_of_condition_expr_if_its_not_false])
Both opinions have some merit to them. How you feel about both styles is largely determined by what you're familiar with and what you're used to. In the first style, you have to learn to ignore some token in some places as they don't add any meaning to the code. In the second, you need to be careful not to mistake one kind of block for another, and you need to learn what is the relation between subexpressions in each kind of block.
Both approaches require learning. The difference is that you already learned the first one, while you're not familiar with the other. But - and that's what I really wanted to say - there's no difference between readability of the two approaches once you learn them. In other words, Lisp code is as readable for Lisp programmers as JavaScript is for JS programmers. Further, all Lisps are equally readable to (a specific) Lisp programmers, just like all Algol-like languages are readable for JS programmers.
With a bit - and I mean a bit, like a few days; if you want a language you won't find readable after half a year, go for J - of practice you could read Lisp-like code without problems. There's no inherent unreadability to either Lisp- or Algol-like syntaxes - is what I'd like to convince you to :)