rust/src/libcoretest/option.rs

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use core::option::*;
use core::kinds::marker;
use core::mem;

#[test]
fn test_get_ptr() {
    unsafe {
        let x = box 0i;
        let addr_x: *const int = mem::transmute(&*x);
        let opt = Some(x);
        let y = opt.unwrap();
        let addr_y: *const int = mem::transmute(&*y);
        assert_eq!(addr_x, addr_y);
    }
}

#[test]
fn test_get_str() {
    let x = "test".to_string();
    let addr_x = x.as_slice().as_ptr();
    let opt = Some(x);
    let y = opt.unwrap();
    let addr_y = y.as_slice().as_ptr();
    assert_eq!(addr_x, addr_y);
}

#[test]
fn test_get_resource() {
    use std::rc::Rc;
    use core::cell::RefCell;

    struct R {
       i: Rc<RefCell<int>>,
    }

    #[unsafe_destructor]
    impl Drop for R {
       fn drop(&mut self) {
            let ii = &*self.i;
            let i = *ii.borrow();
            *ii.borrow_mut() = i + 1;
        }
    }

    fn r(i: Rc<RefCell<int>>) -> R {
        R {
            i: i
        }
    }

    let i = Rc::new(RefCell::new(0i));
    {
        let x = r(i.clone());
        let opt = Some(x);
        let _y = opt.unwrap();
    }
    assert_eq!(*i.borrow(), 1);
}

#[test]
fn test_option_dance() {
    let x = Some(());
    let mut y = Some(5i);
    let mut y2 = 0;
    for _x in x.iter() {
        y2 = y.take_unwrap();
    }
    assert_eq!(y2, 5);
    assert!(y.is_none());
}

#[test] #[should_fail]
fn test_option_too_much_dance() {
    let mut y = Some(marker::NoCopy);
    let _y2 = y.take_unwrap();
    let _y3 = y.take_unwrap();
}

#[test]
fn test_and() {
    let x: Option<int> = Some(1i);
    assert_eq!(x.and(Some(2i)), Some(2));
    assert_eq!(x.and(None::<int>), None);

    let x: Option<int> = None;
    assert_eq!(x.and(Some(2i)), None);
    assert_eq!(x.and(None::<int>), None);
}

#[test]
fn test_and_then() {
    let x: Option<int> = Some(1);
    assert_eq!(x.and_then(|x| Some(x + 1)), Some(2));
    assert_eq!(x.and_then(|_| None::<int>), None);

    let x: Option<int> = None;
    assert_eq!(x.and_then(|x| Some(x + 1)), None);
    assert_eq!(x.and_then(|_| None::<int>), None);
}

#[test]
fn test_or() {
    let x: Option<int> = Some(1);
    assert_eq!(x.or(Some(2)), Some(1));
    assert_eq!(x.or(None), Some(1));

    let x: Option<int> = None;
    assert_eq!(x.or(Some(2)), Some(2));
    assert_eq!(x.or(None), None);
}

#[test]
fn test_or_else() {
    let x: Option<int> = Some(1);
    assert_eq!(x.or_else(|| Some(2)), Some(1));
    assert_eq!(x.or_else(|| None), Some(1));

    let x: Option<int> = None;
    assert_eq!(x.or_else(|| Some(2)), Some(2));
    assert_eq!(x.or_else(|| None), None);
}

#[test]
fn test_option_while_some() {
    let mut i = 0i;
    Some(10i).while_some(|j| {
        i += 1;
        if j > 0 {
            Some(j-1)
        } else {
            None
        }
    });
    assert_eq!(i, 11);
}

#[test]
fn test_unwrap() {
    assert_eq!(Some(1i).unwrap(), 1);
    let s = Some("hello".to_string()).unwrap();
    assert_eq!(s.as_slice(), "hello");
}

#[test]
#[should_fail]
fn test_unwrap_fail1() {
    let x: Option<int> = None;
    x.unwrap();
}

#[test]
#[should_fail]
fn test_unwrap_fail2() {
    let x: Option<String> = None;
    x.unwrap();
}

#[test]
fn test_unwrap_or() {
    let x: Option<int> = Some(1);
    assert_eq!(x.unwrap_or(2), 1);

    let x: Option<int> = None;
    assert_eq!(x.unwrap_or(2), 2);
}

#[test]
fn test_unwrap_or_else() {
    let x: Option<int> = Some(1);
    assert_eq!(x.unwrap_or_else(|| 2), 1);

    let x: Option<int> = None;
    assert_eq!(x.unwrap_or_else(|| 2), 2);
}

#[test]
fn test_filtered() {
    let some_stuff = Some(42i);
    let modified_stuff = some_stuff.filtered(|&x| {x < 10});
    assert_eq!(some_stuff.unwrap(), 42);
    assert!(modified_stuff.is_none());
}

#[test]
fn test_iter() {
    let val = 5i;

    let x = Some(val);
    let mut it = x.iter();

    assert_eq!(it.size_hint(), (1, Some(1)));
    assert_eq!(it.next(), Some(&val));
    assert_eq!(it.size_hint(), (0, Some(0)));
    assert!(it.next().is_none());
}

#[test]
fn test_mut_iter() {
    let val = 5i;
    let new_val = 11i;

    let mut x = Some(val);
    {
        let mut it = x.mut_iter();

        assert_eq!(it.size_hint(), (1, Some(1)));

        match it.next() {
            Some(interior) => {
                assert_eq!(*interior, val);
                *interior = new_val;
            }
            None => assert!(false),
        }

        assert_eq!(it.size_hint(), (0, Some(0)));
        assert!(it.next().is_none());
    }
    assert_eq!(x, Some(new_val));
}

#[test]
fn test_ord() {
    let small = Some(1.0f64);
    let big = Some(5.0f64);
    let nan = Some(0.0f64/0.0);
    assert!(!(nan < big));
    assert!(!(nan > big));
    assert!(small < big);
    assert!(None < big);
    assert!(big > None);
}

#[test]
fn test_mutate() {
    let mut x = Some(3i);
    assert!(x.mutate(|i| i+1));
    assert_eq!(x, Some(4i));
    assert!(x.mutate_or_set(0, |i| i+1));
    assert_eq!(x, Some(5i));
    x = None;
    assert!(!x.mutate(|i| i+1));
    assert_eq!(x, None);
    assert!(!x.mutate_or_set(0i, |i| i+1));
    assert_eq!(x, Some(0i));
}

#[test]
fn test_collect() {
    let v: Option<Vec<int>> = collect(range(0i, 0)
                                      .map(|_| Some(0i)));
    assert!(v == Some(vec![]));

    let v: Option<Vec<int>> = collect(range(0i, 3)
                                      .map(|x| Some(x)));
    assert!(v == Some(vec![0, 1, 2]));

    let v: Option<Vec<int>> = collect(range(0i, 3)
                                      .map(|x| if x > 1 { None } else { Some(x) }));
    assert!(v == None);

    // test that it does not take more elements than it needs
    let mut functions = [|| Some(()), || None, || fail!()];

    let v: Option<Vec<()>> = collect(functions.mut_iter().map(|f| (*f)()));

    assert!(v == None);
}