Wrap higher order function into progress bar - scala

Question

I have an iteration module which can apply an arbitrary function (Build generic reusable iteration module from higher order function) and would love to wrap it into a progressbar.
val things = Range(1,10)
def iterationModule[A](
iterationItems: Seq[A],
functionToApply: A => Any
): Unit = {
iterationItems.foreach(functionToApply)
}
def foo(s:Int) = println(s)
iterationModule[Int](things, foo)
A basic progressbar could look like:
import me.tongfei.progressbar.ProgressBar
val pb = new ProgressBar("Test", things.size)
things.foreach(t=> {
println(t)
pb.step
})
But how can the function which is passed to the iterator module be intercepted and surrounded with a progressbar, i.e. call the pb.step?
An annoying possibility would be to pass the mutable pb object into each function (have it implement an interface).
But is it also possible to intercept and surround the function being passed by this stepping logic?
However, when looping with Seq().par.foreach, this might be problematic.
I need the code to work in Scala 2.11.
edit
A more complex example:
val things = Range(1,100).map(_.toString)
def iterationModule[A](
iterationItems: Seq[A],
functionToApply: A => Any,
parallel: Boolean = false
): Unit = {
val pb = new ProgressBar(functionToApply.toString(), iterationItems.size)
if (parallel) {
iterationItems.par.foreach(functionToApply)
} else {
iterationItems.foreach(functionToApply)
}
}
def doStuff(inputDay: String, inputConfigSomething: String): Unit = println(inputDay + "__"+ inputConfigSomething)
iterationModule[String](things, doStuff(_, "foo"))
The function should be able to take the iteration item and additional parameters.
edit 2
import me.tongfei.progressbar.ProgressBar
val things = Range(1,100).map(_.toString)
def doStuff(inputDay: String, inputConfigSomething: String): Unit = println(inputDay + "__"+ inputConfigSomething)
def iterationModulePb[A](items: Seq[A], f: A => Any, parallel: Boolean = false): Unit = {
val pb = new ProgressBar(f.toString, items.size)
val it = if (parallel) {
items.par.iterator
} else {
items.iterator
}
it.foreach { x =>
f(x)
pb.step()
}
}
iterationModulePb[String](things, doStuff(_, "foo"))
After a little discussion I figured out how to use a Seq with standard iterators.

Answer 1

For Scala 2.13 this would be the most general form.
import me.tongfei.progressbar.ProgressBar
def iterationModule[A](items: IterableOnce[A], f: A => Any): Unit = {
val (it, pb) =
if (items.knowSize != -1)
items.iterator -> new ProgressBar("Test", items.knowSize)
else {
val (iter1, iter2) = items.iterator.split
iter1 -> new ProgressBar("Test", iter2.size)
}
it.foreach { x =>
f(x)
pb.step()
}
}
Note: most of the changes are just to make the code more generic, but the general idea is just to create a function that wraps both the original function and the call to the ProgressBar.
Edit
A simplified solution for 2.11
def iterationModule[A](items: Seq[A], parallel: Boolean = false)
(f: A => Any): Unit = {
val pb = new ProgressBar("test", items.size)
val it = if (parallel) {
items.iterator.par
} else {
items.iterator
}
it.foreach { a =>
f(a)
pb.step()
}
}