A quick comparison of Enum and Stream in Elixir!

Enum and Stream are two powerful modules in the Elixir language that provide collection processing functions. They are similar in many ways but have some key differences. In this article, we'll compare Enum and Stream and help you understand when to use each one.

Enum is the core collection processing module in Elixir. It provides a wide range of functions for processing collections, such as lists, maps, and ranges. Enum functions are designed to be used with finite collections and are optimized for this use case. The Enum functions return the result of the processing as a new collection.

Stream, on the other hand, is a lazy collection processing module. Stream functions also process collections, but instead of returning the result as a new collection, they return a Stream that can be used to generate the result. This allows Stream functions to be used with infinite collections and be more memory efficient.

One of the key differences between Enum and Stream is that Enum functions are eager, meaning that they process the entire collection before returning a result. This can be useful when you need to perform operations on a collection that requires processing the entire collection, such as finding the maximum value. However, it can also be less efficient when processing large collections, since it requires processing the entire collection before returning a result.

Stream functions, on the other hand, are lazy. This means that they only process the collection as it is being consumed. This can be much more efficient when processing large collections, as it allows you to process the collection in smaller chunks, rather than having to process the entire collection at once.

Another difference between Enum and Stream is that Enum functions return the result as a new collection, whereas Stream functions return a Stream that can be used to generate the result. This means that you can't use Enum functions to process infinite collections, since the result would be an infinite collection as well. Stream functions, however, can be used with infinite collections, since they only generate the result as it is being consumed.

In conclusion, both Enum and Stream are powerful collection processing modules in Elixir, each with its own strengths and weaknesses. Enum functions are optimized for processing finite collections and returning the result as a new collection, while Stream functions are optimized for processing infinite collections and being more memory efficient. When choosing between Enum and Stream, consider the size of the collection and whether you need to process the entire collection before returning a result.