39.5 Iteration thunks

Iteration thunks are procedures accepting no arguments and returning an item from a collection; when the iteration finishes: the return value is the void object. Iteration thunks can be used with the facilities of the library (vicare containers iteration-thunks) (see iteration thunks). The following syntactic bindings are exported by the library (vicare containers binary-heaps).

Function: make-binary-heap-iteration-thunk heap

Build and return a new iteration thunk popping the objects from stack.

(import (vicare)
  (vicare containers binary-heaps)
  (vicare containers iteration-thunks))

(define (xcons a b)
  (cons b a))

(iteration-thunk-fold
    xcons
  '()
  (make-binary-heap-iteration-thunk (make-binary-heap <)))
⇒ ()

(let ((H (make-binary-heap <)))
  (binary-heap-fill! H '(3 5 7 0 6 5 34 3 6 9 67 5 4 4 3 1 2 3))
  (iteration-thunk-fold
      xcons
    '()
    (make-binary-heap-iteration-thunk H)))
⇒ (67 34 9 7 6 6 5 5 5 4 4 3 3 3 3 2 1 0)