Lists and Pipelines

Lists use square brackets.

code

let names = ["Nikolas", "Donna"]
let numbers = [1, 2, 3]

List patterns can pull out the head and tail.

code

fn first_or_default(items: List(String)) -> String:
  case items:
    [] -> "none"
    [head, .._] -> head

The pipe operator sends a value into the next function call.

code

import donna/string

fn join_greetings(names: List(String)) -> String:
  string.join(names, ", ")

pub fn main() -> Nil:
  ["Nikolas", "Donna"]
  |> join_greetings
  |> echo

Use pipes when each step has a clear name. If the direct function call is easier to read, use that. Good taste wins.

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