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scalastreamscala-collectionslazylist

What's the difference between LazyList and Stream in Scala?

I noticed that Stream is deprecated in Scala 2.13 and they suggest using LazyList. They also say "Use LazyList (which is fully lazy) instead of Stream (which has a lazy tail only)".
What does it exactly mean ? Why did they deprecate Stream ?

Solution

  • NthPortal, a contributor to LazyList, states in Update and improve LazyList docs #7842

    The key difference between LazyList and Stream - and its key feature - is that whether or not it is lazy is evaluated lazily. I'm not sure how best to convey that.

    jwvh states in related question

    Stream elements are realized lazily except for the 1st (head) element. That was seen as a deficiency.

    Scala 2.13 release notes state

    immutable.LazyList replaces immutable.Stream. Stream had different laziness behavior and is now deprecated. (#7558, #7000)