A higher-order function accepts function values as arguments, returns function values, or does both. In Elixir, it hides recursive iteration behind reusable operations such as Enum.each/2, reducing repetitive loop and tail-recursion code. section 3.4.3
Common Enum operations apply function values to enumerable data:
- Enum.each/2 invokes a lambda for every element without returning a transformed collection. section 3.4.3
- Enum.map/2 performs one-to-one transformation, while capture syntax such as &(2 * &1) makes short functions denser. section 3.4.3
- Enum.filter/2 retains elements selected by a predicate, including reporting missing fields with Map.has_key?/2. section 3.4.3
- Enum.reduce/3 passes each element and accumulator to a function, supporting sums, validation guards, and custom accumulation. section 3.4.3
iex(4)> Enum.reduce(
[1, 2, 3],
0, #1
fn element, sum -> sum + element end #2
)
6
A runnable Enum.reduce/3 example shows a higher-order function receiving an enumerable, an initial accumulator, and a callback that computes the sum. section 3.4.3
