CODEWITHSUNDEEP
scalaiterator
jaywalker
jaywalker

Reputation: 1146

Scala - Iterator being 'consumed'

I am trying to learn Scala through a sample project that I have. In it there is a variable record defined as:

val records: Iterator[Product2[K, V]]

It is passed around in different methods. I explore its contents using :

records.foreach(println)

However, when I try to print the contents using this iterator again, even in successive lines of code, I get no results. It seems as if the iterator is consumed. How do prevent it from happening and be able to explore the contents of the iterator without rendering it useless for the rest of the code?

Upvotes: 1

Views: 284

Answers (1)

Arne Claassen
Arne Claassen

Reputation: 14404

An Iterator extends TraversableOnce and hence can only be iterated over once, as it represents a mutating pointer into an Iterable. If you want something that can be traversable repeatedly and without affecting multiple, parallel accesses, you need to use the Iterable instead, which extends Traversable and on foreach creates a new Iterator for that specific context

Upvotes: 8

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