constraints.rs

use std::io::timer;
use std::time::Duration;
use std::sync::Future;

trait Constraint {
    fn is_satisfied(&self) -> bool;
}
#[deriving(Send)]
struct Foo {
    name: &'static str,
    a: bool,
    b: bool,
}
#[deriving(Send)]
struct Bar {
    name: &'static str,
    a: bool,
}
impl Constraint for Foo {
    fn is_satisfied(&self) -> bool {
        let res = self.a && self.b;
        timer::sleep(Duration::seconds(0));
        println!("{} is {}" , self . name , res);
        res
    }
}
impl Constraint for Bar {
    fn is_satisfied(&self) -> bool {
        let res = self.a;
        println!("{} is {}" , self . name , res);
        res
    }
}
fn main() {
    let mut cs: Vec<Box<Constraint+Send>> = Vec::with_capacity(10);
    cs.push(box() Foo{name: "c1", a: true, b: true,} as Box<Constraint+Send>);
    cs.push(box() Foo{name: "c2", a: true, b: true,} as Box<Constraint+Send>);
    cs.push(box() Foo{name: "c3", a: true, b: true,} as Box<Constraint+Send>);
    cs.push(box() Bar{name: "c4", a: true,} as Box<Constraint+Send>);
    cs.push(box() Bar{name: "c5", a: false,} as Box<Constraint+Send>);
    cs.push(box() Foo{name: "c6", a: true, b: true,} as Box<Constraint+Send>);
    cs.push(box() Foo{name: "c7", a: true, b: true,} as Box<Constraint+Send>);
    cs.push(box() Bar{name: "c8", a: true,} as Box<Constraint+Send>);
    cs.push(box() Bar{name: "c9", a: true,} as Box<Constraint+Send>);
    cs.push(box() Foo{name: "c10", a: true, b: true,} as Box<Constraint+Send>);
    
    let par : Vec<Future<bool>> = cs.into_iter().map(|constraint| Future::spawn(proc(){ constraint.is_satisfied() })).collect();
    let result = par.into_iter().all(|future|future.unwrap());
    if result {
        println!("All conditions satisfied.");
    } else {
        println!("Not all conditions satisfied.");
    }
}