2007/3/19, Nicolas Pouillard <nicolas.pouillard@gmail.com>:
> [...camlp4code...]
> $ cat test_macros.ml
> let cons x xs = x :: xs;;
>
> foldl(( + ), 1, 2, 3, 4);;
> foldr(cons, 1, 2, 3, []);;
>
> $ camlp4o ./macros.cmo test_macros.ml
> let cons x xs = x :: xs
> let _ = ((1 + 2) + 3) + 4
> let _ = cons 1 (cons 2 (cons 3 []))

Impressive.
If it is possible, It would be best would be to be able to write something like:
(def_foldl + plus)

and then just
(+ x y z)
(+ x y z w)
...
The same for cons:
(def_foldr :: cons)

(:: x y z L)
(:: x y z t [])

Such macros are possible, and I think not very hard in Common Lisp. I
will try tonight. As for Camlp4, I don't know. (I don't know camlp4
enough --yet). The point is to define macros that write macro
definitions.

> What's wrong with the current anti quotation system?
Err, actually, nothing... I just found the '$' ugly. But it is one
character, and I may as well use it "as is".

Loup Vaillant