are there any loop constructs? for example: while or do.

[haifenghuang]

I have not see any loop constructs in the OK? language, how do I do loop logic in OK? language?

[ChayimFriedman2]

There is map(), of course, and you can build a sequential one, if you want, by using recursion:

let while = fn(cond, body) {
  if (!cond()) { return NO! }
  body()
  while(cond, body)
}

let i = 1
while(fn() { 10 >= i }, fn() {
  puts("This will be printed ten times")
  i = i + 1
})

Of course, this can blow up the stack, and also will be pretty slow, however I managed this way to run the following code:

timeseq(100000, fn() {
  mapseq([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], fn(item) { item * item })
})

In "just" two and a half minutes, where timeseq() is based on whileseq() which is the above, and mapseq() runs forseq() which is again based on whileseq(). So... Not so bad. Well, terrible, but still...

[jandrese]

So what if you need to iterate over a list with side effects? What if you want to sort the list? What if there is an error halfway through and you need to abort cleanly, like a device went offline and now you need to stop processing and not pound the poor thing with a million further requests? map() is a nice tool, but it has a lot of limitations in the real world. Generally it has to be used judiciously to avoid runaway code.