Generator functions?

Questions & Answers
1

In JavaScript one may create Generator functions by using the function* syntax, as described here: Iterators and generators - JavaScript | MDN
Is it possible to do the same in Racket?
What I would like to obtain is, based on a given list of symbols, a generator that produces new lists by inserting e.g. the symbols + and * at varying places in the given list.

2

You don't need to declare the function differently. You can just use generators in Racket; the docs are here: 4.15.3 Generators

1 Like
3

I think this may be the way to write a function seq-gen that produces a generator, in this case a generator that generates the elements given in the seq list:

(require racket/generator)

(define (seq-gen seq)
  (generator ()
             (let loop ([x seq])
               (if (null? x)
                   0
                   (begin
                     (yield (car x))
                     (loop (cdr x)))))))

(let ([sgen (seq-gen '(A B C))])
  (list (sgen) (sgen) (sgen) (sgen)))

The reason I had problem with this in the beginning was that I forgot to specify (require racket/generator).