elixir enum flat_map

The Enum.flat_map/2 function in Elixir is used to transform each element of a collection into a new collection, and then flatten the resulting collections into a single list. It takes two arguments: the collection to be transformed, and a function that specifies how each element should be transformed.

Here is the syntax for using Enum.flat_map/2:

Enum.flat_map(collection, fun)
  • collection is the input collection that will be transformed.
  • fun is the function that will be applied to each element in the collection.

The fun function should accept a single argument, which represents each element in the collection. It should return a collection as its result. The resulting collections from each element will be combined into a single list.

Here is an example to illustrate how Enum.flat_map/2 works:

list = [1, 2, 3, 4]
result = Enum.flat_map(list, fn(x) -> [x, x * 2] end)
IO.inspect(result) # Output: [1, 2, 2, 4, 3, 6, 4, 8]

In this example, each element in the list is transformed into a new collection containing both the original element and its double. The resulting collections are then flattened into a single list.

Note that Enum.flat_map/2 does not modify the original collection. Instead, it returns a new list with the transformed elements.

This function is useful when you need to apply a transformation to each element of a collection and then combine the results into a single list. It can be used in various scenarios, such as flattening nested lists or generating a new list based on the elements of an existing one.

That's the basic explanation of Enum.flat_map/2 in Elixir. Let me know if you have any further questions.