Lists

Lists

OCaml lists are immutable, singly-linked, and homogeneous. Create them with square brackets and semicolons:

let nums = [1; 2; 3; 4; 5]

Basic Operations

let first = List.hd nums         (* 1 *)
let rest = List.tl nums          (* [2; 3; 4; 5] *)
let len = List.length nums       (* 5 *)
let third = List.nth nums 2      (* 3 *)

Cons Operator (::)

Prepend an element to a list:

let more = 0 :: nums   (* [0; 1; 2; 3; 4; 5] *)

Append (@)

let combined = [1; 2] @ [3; 4]   (* [1; 2; 3; 4] *)

Your Task

Write a recursive function sum_list that computes the sum of a list of integers.