Append Example

First, remove all of the write functions from Then create the module
#lang scheme

(provide append |hello counter| |int hello counter| |inc hello counter|)

(define |hello counter| 0)

(define (|int hello counter|)
  (set! |hello counter| 0))

(define (|inc hello counter|)
  (set! |hello counter|
        (add1 |hello counter|)))

(define (append x y)
  (begin (set! |hello counter| (add1 |hello counter|))
           [(empty? x) y]
           [else (cons (first x) (append (rest x) y))])))
Then in the file, you will need to include this module when you load the code:
(language scheme)
(modules "")
Now any test run with these options will increment the counter by n+1 every time append is called with a list of length n as its first argument.

-- SteveT - 22 Apr 2009

Topic revision: r1 - 2009-04-21 - SteveT
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