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kotlinlang

In the kotlinx immutable collections library (<https://github.com/Kotlin/kotlinx.collections.immutable>), what is the difference between the persistent classes vs immutable classes?

```
Persistent collections: PersistentList, PersistentSet, etc. They extend immutable collections and provide efficient modification operations that return new instances of persistent collections with the modification applied. The returned collections can share parts of data structure with the original persistent collections.
```

So I guess my next question is why do the immutable collections exist at all? It sounds like persistent is a straight upgrade.

immutable collections are immutable and do not provide any modification operations

This library must have changed since last time I used it. My recollection of the immutable classes is how the persistent ones behave now. Thanks you@

yes, it’s essentially reimplemented from scratch interfaces and implementations

old version of interfaces was not work well with existing Kotlin extensions for collection modification