In this case it's more that ignorance is blindness. That syntax is a feature. The fact that Lisp code is expressed in Lisp data structures makes it easy to write programs that write programs.
I'd like to know, though: is that true? Is an abstract syntax tree the only good way to represent programs as data? Has any other expressive way to do this been invented, or do programs always boil down to an AST after the syntax has been stripped away?
I say "expressive" because I can think of at least one other code-as-data representation: binary. But that isn't suitable for programming. If there is another representation that is suitable, but isn't isomorphic to a parse tree, then presumably one could derive from it an analog to Lisp that doesn't simply reduce to Lisp. Until then, though, I think the point that PG made semi-jokingly in the essay, that any language as powerful as Lisp will be a variant of Lisp, has to hold true.
Some day I'd like to research this question (or better, someone on HN could just tell me the answer). If other meaningful representations are possible, surely some must have been invented by now. And if they aren't, then the AST is a considerably more remarkable discovery than people realize.
What would really interest me would be exploring that if human logic fundamentally reduces to a parse tree because of something to do with the language faculty of the mind, and the programming languages that we create tend towards that just because programming languages are built out of the same logical faculty.
That is actually an excellent question.
Now, say I fork lisp and change one little thing:
(defun foo (n) (lambda (i) (incf n i)))
to this:
[defun foo [n] [lambda [i] [incf n i]]]
or even this:
{defun foo {n} {lambda {i} {incf n i}}}
or how about this?
<defun foo <n> <lambda <i> <incf n i>>>
Hmm, trees are powerful, no matter how they are expressed huh?
What if we can represent the same trees using colons and commas as delimiters?
:defun foo:n, :lambda:i, :incf n i.
Maybe spice it up a bit using periods as recursive closing delimiter.
See? still powerful trees!
Between common lisp and colon lisp, I still use the latter.
Love is blindness.
Ergonomics win.
I don't see what you're trying to claim. Initially you seemed to be saying that you preferred conventional sytax to sexprs. I pointed out that this meant you had to give up macros. You reply that you could use other characters to delimit sexprs. Sure, but so what?