(loop
for element in sequence
collect (do-something-to element)
until (> element 5))

This performs some action on each element (do-something-to) and
collects the results in a list (the return value of loop). If it runs
into an element that is greater than 5, it will terminate early and
return whatever it collected so far.

(use srfi-42) ;; list-ec for Gauche Scheme.
or
(require srfi/42) ;; list-ec for Racket.

(define nums '(-8 0 4 6 9))

(list-ec (:until (:list x nums) (> x 5)) (abs x))


(8 0 4 6)

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Don Geddis wrote:

Is there any generic iteration contruct for sequences? Ideally it
would work just like DOLIST.
> (do-sequence (e "ab c")
(print e))
#\a
#\b
#\Space
#\c
nil

Well, I don't know if you consider the LOOP macro to be Common Lisp, but
the following works in Allegro CL 4.2:

USER(20): (loop for x across "ab c" do (print x))

#\a
#\b
#\space
#\c
NIL

CLtL2 says that the "across" keyword works for iteration over arrays (vectors),
so it looks to be not quite as generic as over sequences. But it's close.

Gauche Scheme

(use gauche.collection)

(for-each print '(a b c))
a
b
c

(for-each print #(a b c))
a
b
c

(for-each print "abc")
a
b
c

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