Looking at HTDP-1
(http://htdp.org/2003-09-26/Book/curriculum-Z-H-25.html#node_chap_19), I see
this:
(define (filter predicate alon)
(cond
[(empty? alon) empty]
[else (cond
[(predicate (first alon))
(cons (first alon)
(filter predicate (rest alon)))]
[else
(filter predicate (rest alon))])]))
Then to find if a member of a list l is below a number i
(define (below i l)
(local ((define (below-i x)
(> i x)))
(filter below-i l)))
As the proverbial beginner -- who doesn't totally understand closures -- this
looks like a use of the closure idea. Right? The i is "magically" known in
`filter`, which seems pretty closure-ish to me. Or am I totally wrong?
LB
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