XPost: comp.lang.scheme

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 ...))]))

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XPost: comp.lang.scheme

On 2024-09-26, B. Pym <Nobody447095@here-nor-there.org> wrote:

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 ...))]))

TXR Lisp:

[mapcar + '(10 20 30) 0]

(10 21 32)

Given: TMF language, and that's it.

--
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
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