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use std;
use std::rand;
use uint::range;
// random uint less than n
fn under(r : rand::rng, n : uint) -> uint {
assert n != 0u; r.next() as uint % n
}
// random choice from a vec
fn choice<T: copy>(r : rand::rng, v : ~[const T]) -> T {
assert vec::len(v) != 0u; v[under(r, vec::len(v))]
}
// k in n chance of being true
fn likelihood(r : rand::rng, k : uint, n : uint) -> bool { under(r, n) < k }
const iters : uint = 1000u;
const vlen : uint = 100u;
enum maybe_pointy {
none,
p(@pointy)
}
type pointy = {
mut a : maybe_pointy,
mut b : ~maybe_pointy,
mut c : @maybe_pointy,
mut f : fn@()->(),
mut g : fn~()->(),
mut m : ~[maybe_pointy],
mut n : ~[mut maybe_pointy],
mut o : {x : int, y : maybe_pointy}
};
// To add: objects; traits; anything type-parameterized?
fn empty_pointy() -> @pointy {
return @{
mut a : none,
mut b : ~none,
mut c : @none,
mut f : fn@()->(){},
mut g : fn~()->(){},
mut m : ~[],
mut n : ~[mut],
mut o : {x : 0, y : none}
}
}
fn nopP(_x : @pointy) { }
fn nop<T>(_x: T) { }
fn test_cycles(r : rand::rng, k: uint, n: uint)
{
let v : ~[mut @pointy] = ~[mut];
// Create a graph with no edges
range(0u, vlen) {|_i|
v.push(empty_pointy());
}
// Fill in the graph with random edges, with density k/n
range(0u, vlen) {|i|
if (likelihood(r, k, n)) { v[i].a = p(choice(r, v)); }
if (likelihood(r, k, n)) { v[i].b = ~p(choice(r, v)); }
if (likelihood(r, k, n)) { v[i].c = @p(choice(r, v)); }
if (likelihood(r, k, n)) { v[i].f = bind nopP(choice(r, v)); }
//if (false) { v[i].g = bind (fn~(_x: @pointy) { })(
// choice(r, v)); }
// https://github.com/mozilla/rust/issues/1899
if (likelihood(r, k, n)) { v[i].m = [p(choice(r, v))]; }
if (likelihood(r, k, n)) { v[i].n.push(mut p(choice(r, v))); }
if (likelihood(r, k, n)) { v[i].o = {x: 0, y: p(choice(r, v))}; }
}
// Drop refs one at a time
range(0u, vlen) {|i|
v[i] = empty_pointy()
}
}
fn main()
{
let r = rand::rng();
range(0u, iters) {|i|
test_cycles(r, i, iters);
}
}
|
