fold

fn fold(Vec<int> xs, int init, int -> int -> int folder) -> int

use collections::vec::{fold};

Combines the elements left to right: starts from init and replaces the accumulator with folder(acc)(x) for each x.

folder is curried: it takes the accumulator and returns a function of the element. Only Vec<int> is supported for now.

Parameters#

Returns#

int

Examples#

use collections::vec::{fold};
use tests::assert;
let xs: Vec<int> = [1, 2, 3, 4];
let total = fold(xs, 0, fn (int acc) => fn (int x) use (acc) => acc + x);
assert!(total == 10);

See also#

• Vec
• fold_int: The same as fold; kept for older code.
• contains: Returns true when needle is in xs.
• index_of: Returns the index of the first needle in xs, or -1.
• binary_search: Finds needle in the ascending vector xs by halving, and returns an index holding it.
• dedup: Returns xs with runs of equal neighbours collapsed to one value.
• map: Returns a new vector with mapper applied to each element, in order.
• filter: Returns the elements for which pred is true, in order.