; Misc handy library functions (many based on Haskell and ML)
; Copyright 2005 Brian Alliet

; delete the first element from a list which is equal? to x
; FEATURE: Use an accumulator
(define (delete y xs)
    (match xs
        ('() '())
        ((cons x xs) (if (equal? x y) xs (cons x (delete y xs))))
    ))

; replace replaces the first element of a list equal? to old with new
; FEATURE: Use an accumulator
(define (replace old new xs)
    (match xs
        ('() '())
        ((cons x xs) (if (equal? old x) (cons new xs) (cons x (replace old new xs))))
    ))