use std;

import std::vec::*;
import std::option;

#[test]
fn test_init_elt() {
    let v: vec[uint] = init_elt[uint](5u, 3u);
    assert (len[uint](v) == 3u);
    assert (v.(0) == 5u);
    assert (v.(1) == 5u);
    assert (v.(2) == 5u);
}

fn id(x: uint) -> uint { ret x; }

#[test]
fn test_init_fn() {
    let op: fn(uint) -> uint  = id;
    let v: vec[uint] = init_fn[uint](op, 5u);
    assert (len[uint](v) == 5u);
    assert (v.(0) == 0u);
    assert (v.(1) == 1u);
    assert (v.(2) == 2u);
    assert (v.(3) == 3u);
    assert (v.(4) == 4u);
}

#[test]
fn test_slice() {
    let v: vec[int] = [1, 2, 3, 4, 5];
    let v2 = slice[int](v, 2u, 4u);
    assert (len[int](v2) == 2u);
    assert (v2.(0) == 3);
    assert (v2.(1) == 4);
}

#[test]
fn test_map() {
    fn square(x: &int) -> int { ret x * x; }
    let v: vec[int] = [1, 2, 3, 4, 5];
    let s: vec[int] = map(square, v);
    let i: int = 0;
    while i < 5 { assert (v.(i) * v.(i) == s.(i)); i += 1; }
}

#[test]
fn test_map2() {
    fn times(x: &int, y: &int) -> int { ret x * y; }
    let f = times;
    let v0 = [1, 2, 3, 4, 5];
    let v1 = [5, 4, 3, 2, 1];
    let u = map2[int, int, int](f, v0, v1);
    let i = 0;
    while i < 5 { assert (v0.(i) * v1.(i) == u.(i)); i += 1; }
}

#[test]
fn test_filter_map() {
    fn halve(i: &int) -> option::t[int] {
        if i % 2 == 0 {
            ret option::some[int](i / 2);
        } else { ret option::none[int]; }
    }
    fn halve_for_sure(i: &int) -> int { ret i / 2; }
    let all_even: vec[int] = [0, 2, 8, 6];
    let all_odd1: vec[int] = [1, 7, 3];
    let all_odd2: vec[int] = [];
    let mix: vec[int] = [9, 2, 6, 7, 1, 0, 0, 3];
    let mix_dest: vec[int] = [1, 3, 0, 0];
    assert (filter_map(halve, all_even) == map(halve_for_sure, all_even));
    assert (filter_map(halve, all_odd1) == empty[int]());
    assert (filter_map(halve, all_odd2) == empty[int]());
    assert (filter_map(halve, mix) == mix_dest);
}

#[test]
fn test_position() {
    let v1: vec[int] = [1, 2, 3, 3, 2, 5];
    assert (position(1, v1) == option::some[uint](0u));
    assert (position(2, v1) == option::some[uint](1u));
    assert (position(5, v1) == option::some[uint](5u));
    assert (position(4, v1) == option::none[uint]);
}

#[test]
fn test_position_pred() {
    fn less_than_three(i: &int) -> bool { ret i < 3; }
    fn is_eighteen(i: &int) -> bool { ret i == 18; }
    let v1: vec[int] = [5, 4, 3, 2, 1];
    assert (position_pred(less_than_three, v1) == option::some[uint](3u));
    assert (position_pred(is_eighteen, v1) == option::none[uint]);
}