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|
;; run with mzscheme -r example.scm
(load-extension "example.so")
; repeatedly invoke a procedure with v and an index as arguments
(define (with-vector v proc size-proc)
(let ((size (size-proc v)))
(define (with-vector-item v i)
(if (< i size)
(begin
(proc v i)
(with-vector-item v (+ i 1)))))
(with-vector-item v 0)))
(define (with-intvector v proc)
(with-vector v proc intvector-length))
(define (with-doublevector v proc)
(with-vector v proc doublevector-length))
(define (print-doublevector v)
(with-doublevector v (lambda (v i) (display (doublevector-ref v i))
(display " ")))
(newline))
; Call average with a Scheme list...
(display (average '(1 2 3 4)))
(newline)
; ... or a wrapped std::vector<int>
(define v (new-intvector 4))
(with-intvector v (lambda (v i) (intvector-set! v i (+ i 1))))
(display (average v))
(newline)
(delete-intvector v)
; half will return a Scheme vector.
; Call it with a Scheme vector...
(display (half #(1 1.5 2 2.5 3)))
(newline)
; ... or a wrapped std::vector<double>
(define v (new-doublevector))
(map (lambda (i) (doublevector-push! v i)) '(1 2 3 4))
(display (half v))
(newline)
; now halve a wrapped std::vector<double> in place
(halve-in-place v)
(print-doublevector v)
(delete-doublevector v)
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