Tuesday, June 08, 2004

Scheme woes - too tired now. Will be obvious in the morning.

insertR is a function that adds its first parameter into a list (its third parameter) directly after the first occurence of its second parameter.
I have MZScheme. I execute:
    (insertR 3 2 '(1 2))

I get
    (1 2 3)

That floats my boat. Now I fire up SISC 1.8.8. Again, I execute:
    (insertR 3 2 '(1 2))

This time I get:
    (1 2)

What gives?

(define insertR
(lambda (new old lat)
((null? lat) '())
((eq? (car lat) old) (cons old (cons new (cdr lat))))
(cons (car lat) (insertR new old (cdr lat)))))))))

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