Re: Simple problem in PG's ANSI Common Lisp

paul graham wrote:

Or you could write
 
(defun pos+ (lst)
  (let ((i -1))
    (mapcar #'(lambda (x) (+ x (incf i)))
            lst)))
 
Btw, in Arc that would be
 
(def pos+ (lst)
  (let i -1
    (map [+ _ (++ i)] lst)))

Gauche Scheme

(define (pos+ lst)
  (let1 i -1
    (map (~>  (+ (inc! i))) lst)))

Given:

(define-syntax ->
  (syntax-rules ()
    [(_ x)  x]
    [(_ x (y more ...) z ...)
     (-> (y x more ...) z ...)]
    [(_ x y z ...)
     (-> (y x) z ...)]))

(define-syntax ~>
  (syntax-rules ()
    [(_ (func0 a ...) func ...)
     (lambda xs (-> (apply func0 (append xs (list a ...))) func ...))]
    [(_ func0 func ...)
     (lambda xs (-> (apply func0 xs) func ...))]))