4 ms·

pseudo-ml factorial n = case | n <= 1 -> 1 | else -> n * factorial (n - 1) i can see what's going on at a glance - the syntax and layout of the

• saurik 14y ago
  You changed the structure, though, to use something much closer to a cond instead of an if. Also, there are variants that require fewer ()s for this. clisp: (defun factorial (n) (cond ((<= n 1) 1) (T (* n (factorial (- n 1)))))) Clojure (which I believe is similar to Ark with respect to not using extra parentheses around cond clauses, but I don't have Ark setup to verify that that's actually the case and then to test my demonstration with, so I'm going to do it with Clojure, despite the "weird" [] syntax, as it is orthogonal to the demonstration): (defn factorial [n] (cond (<= n 1) 1 :else (* n (factorial (dec n)))))
  • zem 14y ago
    fair point (i was actually planning on adding a lisp cond by way of contrast, and then forgot). my contention is that the ml cond looks a lot less cluttered than the lisp one, and is therefore more pleasant to read. the clojure one is nicer since it lacks the visual clutter of the per-case enclosing parens, but it feels slightly wrong from a lisp perspective since i'm now replacing [(a, b), (c, d)] with [a, b, c, d] which has changed the innate structure of the expression. i actually like the racket convention of using square brackets to distinguish this the best of all the lispy options: (defn factorial [n] (cond [(<= n 1) 1] [:else (* n (factorial (dec n)))]))
    • gcr 14y ago
      For the record, that isn't valid racket code. This is: (define (factorial n) (cond [(<= n 1) 1] [else (* n (factorial (sub1 n)))]))