chickadee » srfi-121 » make-coroutine-generator

make-coroutine-generator procprocedure

Creates a generator from a coroutine.

The proc argument is a procedure that takes one argument, yield. When called, make-coroutine-generator immediately returns a generator g. When g is called, proc runs until it calls yield. Calling yield causes the execution of proc to be suspended, and g returns the value passed to yield.

Whether this generator is finite or infinite depends on the behavior of proc. If proc returns, it is the end of the sequence — g returns an end-of-file object from then on. The return value of proc is ignored.

The following code creates a generator that produces a series 0, 1, and 2 (effectively the same as (make-range-generator 0 3) and binds it to g.

(define g
   (lambda (yield)
     (let loop ((i 0))
       (when (< i 3) (yield i) (loop (+ i 1)))))))

(generator->list g) ⇒ (0 1 2)