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Diffstat (limited to 'src/libcore/tests/iter.rs')
| -rw-r--r-- | src/libcore/tests/iter.rs | 1084 |
1 files changed, 1084 insertions, 0 deletions
diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs new file mode 100644 index 00000000000..08442f9bcbf --- /dev/null +++ b/src/libcore/tests/iter.rs @@ -0,0 +1,1084 @@ +// 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::iter::*; +use core::{i8, i16, isize}; +use core::usize; + +#[test] +fn test_lt() { + let empty: [isize; 0] = []; + let xs = [1,2,3]; + let ys = [1,2,0]; + + assert!(!xs.iter().lt(ys.iter())); + assert!(!xs.iter().le(ys.iter())); + assert!( xs.iter().gt(ys.iter())); + assert!( xs.iter().ge(ys.iter())); + + assert!( ys.iter().lt(xs.iter())); + assert!( ys.iter().le(xs.iter())); + assert!(!ys.iter().gt(xs.iter())); + assert!(!ys.iter().ge(xs.iter())); + + assert!( empty.iter().lt(xs.iter())); + assert!( empty.iter().le(xs.iter())); + assert!(!empty.iter().gt(xs.iter())); + assert!(!empty.iter().ge(xs.iter())); + + // Sequence with NaN + let u = [1.0f64, 2.0]; + let v = [0.0f64/0.0, 3.0]; + + assert!(!u.iter().lt(v.iter())); + assert!(!u.iter().le(v.iter())); + assert!(!u.iter().gt(v.iter())); + assert!(!u.iter().ge(v.iter())); + + let a = [0.0f64/0.0]; + let b = [1.0f64]; + let c = [2.0f64]; + + assert!(a.iter().lt(b.iter()) == (a[0] < b[0])); + assert!(a.iter().le(b.iter()) == (a[0] <= b[0])); + assert!(a.iter().gt(b.iter()) == (a[0] > b[0])); + assert!(a.iter().ge(b.iter()) == (a[0] >= b[0])); + + assert!(c.iter().lt(b.iter()) == (c[0] < b[0])); + assert!(c.iter().le(b.iter()) == (c[0] <= b[0])); + assert!(c.iter().gt(b.iter()) == (c[0] > b[0])); + assert!(c.iter().ge(b.iter()) == (c[0] >= b[0])); +} + +#[test] +fn test_multi_iter() { + let xs = [1,2,3,4]; + let ys = [4,3,2,1]; + assert!(xs.iter().eq(ys.iter().rev())); + assert!(xs.iter().lt(xs.iter().skip(2))); +} + +#[test] +fn test_counter_from_iter() { + let it = (0..).step_by(5).take(10); + let xs: Vec<isize> = FromIterator::from_iter(it); + assert_eq!(xs, [0, 5, 10, 15, 20, 25, 30, 35, 40, 45]); +} + +#[test] +fn test_iterator_chain() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [30, 40, 50, 60]; + let expected = [0, 1, 2, 3, 4, 5, 30, 40, 50, 60]; + let it = xs.iter().chain(&ys); + let mut i = 0; + for &x in it { + assert_eq!(x, expected[i]); + i += 1; + } + assert_eq!(i, expected.len()); + + let ys = (30..).step_by(10).take(4); + let it = xs.iter().cloned().chain(ys); + let mut i = 0; + for x in it { + assert_eq!(x, expected[i]); + i += 1; + } + assert_eq!(i, expected.len()); +} + +#[test] +fn test_iterator_chain_nth() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [30, 40, 50, 60]; + let zs = []; + let expected = [0, 1, 2, 3, 4, 5, 30, 40, 50, 60]; + for (i, x) in expected.iter().enumerate() { + assert_eq!(Some(x), xs.iter().chain(&ys).nth(i)); + } + assert_eq!(zs.iter().chain(&xs).nth(0), Some(&0)); + + let mut it = xs.iter().chain(&zs); + assert_eq!(it.nth(5), Some(&5)); + assert_eq!(it.next(), None); +} + +#[test] +fn test_iterator_chain_last() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [30, 40, 50, 60]; + let zs = []; + assert_eq!(xs.iter().chain(&ys).last(), Some(&60)); + assert_eq!(zs.iter().chain(&ys).last(), Some(&60)); + assert_eq!(ys.iter().chain(&zs).last(), Some(&60)); + assert_eq!(zs.iter().chain(&zs).last(), None); +} + +#[test] +fn test_iterator_chain_count() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [30, 40, 50, 60]; + let zs = []; + assert_eq!(xs.iter().chain(&ys).count(), 10); + assert_eq!(zs.iter().chain(&ys).count(), 4); +} + +#[test] +fn test_iterator_chain_find() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [30, 40, 50, 60]; + let mut iter = xs.iter().chain(&ys); + assert_eq!(iter.find(|&&i| i == 4), Some(&4)); + assert_eq!(iter.next(), Some(&5)); + assert_eq!(iter.find(|&&i| i == 40), Some(&40)); + assert_eq!(iter.next(), Some(&50)); + assert_eq!(iter.find(|&&i| i == 100), None); + assert_eq!(iter.next(), None); +} + +#[test] +fn test_filter_map() { + let it = (0..).step_by(1).take(10) + .filter_map(|x| if x % 2 == 0 { Some(x*x) } else { None }); + assert_eq!(it.collect::<Vec<usize>>(), [0*0, 2*2, 4*4, 6*6, 8*8]); +} + +#[test] +fn test_iterator_enumerate() { + let xs = [0, 1, 2, 3, 4, 5]; + let it = xs.iter().enumerate(); + for (i, &x) in it { + assert_eq!(i, x); + } +} + +#[test] +fn test_iterator_enumerate_nth() { + let xs = [0, 1, 2, 3, 4, 5]; + for (i, &x) in xs.iter().enumerate() { + assert_eq!(i, x); + } + + let mut it = xs.iter().enumerate(); + while let Some((i, &x)) = it.nth(0) { + assert_eq!(i, x); + } + + let mut it = xs.iter().enumerate(); + while let Some((i, &x)) = it.nth(1) { + assert_eq!(i, x); + } + + let (i, &x) = xs.iter().enumerate().nth(3).unwrap(); + assert_eq!(i, x); + assert_eq!(i, 3); +} + +#[test] +fn test_iterator_enumerate_count() { + let xs = [0, 1, 2, 3, 4, 5]; + assert_eq!(xs.iter().count(), 6); +} + +#[test] +fn test_iterator_filter_count() { + let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8]; + assert_eq!(xs.iter().filter(|&&x| x % 2 == 0).count(), 5); +} + +#[test] +fn test_iterator_peekable() { + let xs = vec![0, 1, 2, 3, 4, 5]; + let mut it = xs.iter().cloned().peekable(); + + assert_eq!(it.len(), 6); + assert_eq!(it.peek().unwrap(), &0); + assert_eq!(it.len(), 6); + assert_eq!(it.next().unwrap(), 0); + assert_eq!(it.len(), 5); + assert_eq!(it.next().unwrap(), 1); + assert_eq!(it.len(), 4); + assert_eq!(it.next().unwrap(), 2); + assert_eq!(it.len(), 3); + assert_eq!(it.peek().unwrap(), &3); + assert_eq!(it.len(), 3); + assert_eq!(it.peek().unwrap(), &3); + assert_eq!(it.len(), 3); + assert_eq!(it.next().unwrap(), 3); + assert_eq!(it.len(), 2); + assert_eq!(it.next().unwrap(), 4); + assert_eq!(it.len(), 1); + assert_eq!(it.peek().unwrap(), &5); + assert_eq!(it.len(), 1); + assert_eq!(it.next().unwrap(), 5); + assert_eq!(it.len(), 0); + assert!(it.peek().is_none()); + assert_eq!(it.len(), 0); + assert!(it.next().is_none()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_iterator_peekable_count() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [10]; + let zs: [i32; 0] = []; + + assert_eq!(xs.iter().peekable().count(), 6); + + let mut it = xs.iter().peekable(); + assert_eq!(it.peek(), Some(&&0)); + assert_eq!(it.count(), 6); + + assert_eq!(ys.iter().peekable().count(), 1); + + let mut it = ys.iter().peekable(); + assert_eq!(it.peek(), Some(&&10)); + assert_eq!(it.count(), 1); + + assert_eq!(zs.iter().peekable().count(), 0); + + let mut it = zs.iter().peekable(); + assert_eq!(it.peek(), None); + +} + +#[test] +fn test_iterator_peekable_nth() { + let xs = [0, 1, 2, 3, 4, 5]; + let mut it = xs.iter().peekable(); + + assert_eq!(it.peek(), Some(&&0)); + assert_eq!(it.nth(0), Some(&0)); + assert_eq!(it.peek(), Some(&&1)); + assert_eq!(it.nth(1), Some(&2)); + assert_eq!(it.peek(), Some(&&3)); + assert_eq!(it.nth(2), Some(&5)); + assert_eq!(it.next(), None); +} + +#[test] +fn test_iterator_peekable_last() { + let xs = [0, 1, 2, 3, 4, 5]; + let ys = [0]; + + let mut it = xs.iter().peekable(); + assert_eq!(it.peek(), Some(&&0)); + assert_eq!(it.last(), Some(&5)); + + let mut it = ys.iter().peekable(); + assert_eq!(it.peek(), Some(&&0)); + assert_eq!(it.last(), Some(&0)); + + let mut it = ys.iter().peekable(); + assert_eq!(it.next(), Some(&0)); + assert_eq!(it.peek(), None); + assert_eq!(it.last(), None); +} + +/// This is an iterator that follows the Iterator contract, +/// but it is not fused. After having returned None once, it will start +/// producing elements if .next() is called again. +pub struct CycleIter<'a, T: 'a> { + index: usize, + data: &'a [T], +} + +pub fn cycle<T>(data: &[T]) -> CycleIter<T> { + CycleIter { + index: 0, + data: data, + } +} + +impl<'a, T> Iterator for CycleIter<'a, T> { + type Item = &'a T; + fn next(&mut self) -> Option<Self::Item> { + let elt = self.data.get(self.index); + self.index += 1; + self.index %= 1 + self.data.len(); + elt + } +} + +#[test] +fn test_iterator_peekable_remember_peek_none_1() { + // Check that the loop using .peek() terminates + let data = [1, 2, 3]; + let mut iter = cycle(&data).peekable(); + + let mut n = 0; + while let Some(_) = iter.next() { + let is_the_last = iter.peek().is_none(); + assert_eq!(is_the_last, n == data.len() - 1); + n += 1; + if n > data.len() { break; } + } + assert_eq!(n, data.len()); +} + +#[test] +fn test_iterator_peekable_remember_peek_none_2() { + let data = [0]; + let mut iter = cycle(&data).peekable(); + iter.next(); + assert_eq!(iter.peek(), None); + assert_eq!(iter.last(), None); +} + +#[test] +fn test_iterator_peekable_remember_peek_none_3() { + let data = [0]; + let mut iter = cycle(&data).peekable(); + iter.peek(); + assert_eq!(iter.nth(0), Some(&0)); + + let mut iter = cycle(&data).peekable(); + iter.next(); + assert_eq!(iter.peek(), None); + assert_eq!(iter.nth(0), None); +} + +#[test] +fn test_iterator_take_while() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [0, 1, 2, 3, 5, 13]; + let it = xs.iter().take_while(|&x| *x < 15); + let mut i = 0; + for x in it { + assert_eq!(*x, ys[i]); + i += 1; + } + assert_eq!(i, ys.len()); +} + +#[test] +fn test_iterator_skip_while() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [15, 16, 17, 19]; + let it = xs.iter().skip_while(|&x| *x < 15); + let mut i = 0; + for x in it { + assert_eq!(*x, ys[i]); + i += 1; + } + assert_eq!(i, ys.len()); +} + +#[test] +fn test_iterator_skip() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + let ys = [13, 15, 16, 17, 19, 20, 30]; + let mut it = xs.iter().skip(5); + let mut i = 0; + while let Some(&x) = it.next() { + assert_eq!(x, ys[i]); + i += 1; + assert_eq!(it.len(), xs.len()-5-i); + } + assert_eq!(i, ys.len()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_iterator_skip_doubleended() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + let mut it = xs.iter().rev().skip(5); + assert_eq!(it.next(), Some(&15)); + assert_eq!(it.by_ref().rev().next(), Some(&0)); + assert_eq!(it.next(), Some(&13)); + assert_eq!(it.by_ref().rev().next(), Some(&1)); + assert_eq!(it.next(), Some(&5)); + assert_eq!(it.by_ref().rev().next(), Some(&2)); + assert_eq!(it.next(), Some(&3)); + assert_eq!(it.next(), None); + let mut it = xs.iter().rev().skip(5).rev(); + assert_eq!(it.next(), Some(&0)); + assert_eq!(it.rev().next(), Some(&15)); + let mut it_base = xs.iter(); + { + let mut it = it_base.by_ref().skip(5).rev(); + assert_eq!(it.next(), Some(&30)); + assert_eq!(it.next(), Some(&20)); + assert_eq!(it.next(), Some(&19)); + assert_eq!(it.next(), Some(&17)); + assert_eq!(it.next(), Some(&16)); + assert_eq!(it.next(), Some(&15)); + assert_eq!(it.next(), Some(&13)); + assert_eq!(it.next(), None); + } + // make sure the skipped parts have not been consumed + assert_eq!(it_base.next(), Some(&0)); + assert_eq!(it_base.next(), Some(&1)); + assert_eq!(it_base.next(), Some(&2)); + assert_eq!(it_base.next(), Some(&3)); + assert_eq!(it_base.next(), Some(&5)); + assert_eq!(it_base.next(), None); + let it = xs.iter().skip(5).rev(); + assert_eq!(it.last(), Some(&13)); +} + +#[test] +fn test_iterator_skip_nth() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + + let mut it = xs.iter().skip(0); + assert_eq!(it.nth(0), Some(&0)); + assert_eq!(it.nth(1), Some(&2)); + + let mut it = xs.iter().skip(5); + assert_eq!(it.nth(0), Some(&13)); + assert_eq!(it.nth(1), Some(&16)); + + let mut it = xs.iter().skip(12); + assert_eq!(it.nth(0), None); + +} + +#[test] +fn test_iterator_skip_count() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + + assert_eq!(xs.iter().skip(0).count(), 12); + assert_eq!(xs.iter().skip(1).count(), 11); + assert_eq!(xs.iter().skip(11).count(), 1); + assert_eq!(xs.iter().skip(12).count(), 0); + assert_eq!(xs.iter().skip(13).count(), 0); +} + +#[test] +fn test_iterator_skip_last() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + + assert_eq!(xs.iter().skip(0).last(), Some(&30)); + assert_eq!(xs.iter().skip(1).last(), Some(&30)); + assert_eq!(xs.iter().skip(11).last(), Some(&30)); + assert_eq!(xs.iter().skip(12).last(), None); + assert_eq!(xs.iter().skip(13).last(), None); + + let mut it = xs.iter().skip(5); + assert_eq!(it.next(), Some(&13)); + assert_eq!(it.last(), Some(&30)); +} + +#[test] +fn test_iterator_take() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [0, 1, 2, 3, 5]; + let mut it = xs.iter().take(5); + let mut i = 0; + assert_eq!(it.len(), 5); + while let Some(&x) = it.next() { + assert_eq!(x, ys[i]); + i += 1; + assert_eq!(it.len(), 5-i); + } + assert_eq!(i, ys.len()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_iterator_take_nth() { + let xs = [0, 1, 2, 4, 5]; + let mut it = xs.iter(); + { + let mut take = it.by_ref().take(3); + let mut i = 0; + while let Some(&x) = take.nth(0) { + assert_eq!(x, i); + i += 1; + } + } + assert_eq!(it.nth(1), Some(&5)); + assert_eq!(it.nth(0), None); + + let xs = [0, 1, 2, 3, 4]; + let mut it = xs.iter().take(7); + let mut i = 1; + while let Some(&x) = it.nth(1) { + assert_eq!(x, i); + i += 2; + } +} + +#[test] +fn test_iterator_take_short() { + let xs = [0, 1, 2, 3]; + let ys = [0, 1, 2, 3]; + let mut it = xs.iter().take(5); + let mut i = 0; + assert_eq!(it.len(), 4); + while let Some(&x) = it.next() { + assert_eq!(x, ys[i]); + i += 1; + assert_eq!(it.len(), 4-i); + } + assert_eq!(i, ys.len()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_iterator_scan() { + // test the type inference + fn add(old: &mut isize, new: &usize) -> Option<f64> { + *old += *new as isize; + Some(*old as f64) + } + let xs = [0, 1, 2, 3, 4]; + let ys = [0f64, 1.0, 3.0, 6.0, 10.0]; + + let it = xs.iter().scan(0, add); + let mut i = 0; + for x in it { + assert_eq!(x, ys[i]); + i += 1; + } + assert_eq!(i, ys.len()); +} + +#[test] +fn test_iterator_flat_map() { + let xs = [0, 3, 6]; + let ys = [0, 1, 2, 3, 4, 5, 6, 7, 8]; + let it = xs.iter().flat_map(|&x| (x..).step_by(1).take(3)); + let mut i = 0; + for x in it { + assert_eq!(x, ys[i]); + i += 1; + } + assert_eq!(i, ys.len()); +} + +#[test] +fn test_inspect() { + let xs = [1, 2, 3, 4]; + let mut n = 0; + + let ys = xs.iter() + .cloned() + .inspect(|_| n += 1) + .collect::<Vec<usize>>(); + + assert_eq!(n, xs.len()); + assert_eq!(&xs[..], &ys[..]); +} + +#[test] +fn test_cycle() { + let cycle_len = 3; + let it = (0..).step_by(1).take(cycle_len).cycle(); + assert_eq!(it.size_hint(), (usize::MAX, None)); + for (i, x) in it.take(100).enumerate() { + assert_eq!(i % cycle_len, x); + } + + let mut it = (0..).step_by(1).take(0).cycle(); + assert_eq!(it.size_hint(), (0, Some(0))); + assert_eq!(it.next(), None); +} + +#[test] +fn test_iterator_nth() { + let v: &[_] = &[0, 1, 2, 3, 4]; + for i in 0..v.len() { + assert_eq!(v.iter().nth(i).unwrap(), &v[i]); + } + assert_eq!(v.iter().nth(v.len()), None); +} + +#[test] +fn test_iterator_last() { + let v: &[_] = &[0, 1, 2, 3, 4]; + assert_eq!(v.iter().last().unwrap(), &4); + assert_eq!(v[..1].iter().last().unwrap(), &0); +} + +#[test] +fn test_iterator_len() { + let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + assert_eq!(v[..4].iter().count(), 4); + assert_eq!(v[..10].iter().count(), 10); + assert_eq!(v[..0].iter().count(), 0); +} + +#[test] +fn test_iterator_sum() { + let v: &[i32] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + assert_eq!(v[..4].iter().cloned().sum::<i32>(), 6); + assert_eq!(v.iter().cloned().sum::<i32>(), 55); + assert_eq!(v[..0].iter().cloned().sum::<i32>(), 0); +} + +#[test] +fn test_iterator_sum_result() { + let v: &[Result<i32, ()>] = &[Ok(1), Ok(2), Ok(3), Ok(4)]; + assert_eq!(v.iter().cloned().sum::<Result<i32, _>>(), Ok(10)); + let v: &[Result<i32, ()>] = &[Ok(1), Err(()), Ok(3), Ok(4)]; + assert_eq!(v.iter().cloned().sum::<Result<i32, _>>(), Err(())); +} + +#[test] +fn test_iterator_product() { + let v: &[i32] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + assert_eq!(v[..4].iter().cloned().product::<i32>(), 0); + assert_eq!(v[1..5].iter().cloned().product::<i32>(), 24); + assert_eq!(v[..0].iter().cloned().product::<i32>(), 1); +} + +#[test] +fn test_iterator_product_result() { + let v: &[Result<i32, ()>] = &[Ok(1), Ok(2), Ok(3), Ok(4)]; + assert_eq!(v.iter().cloned().product::<Result<i32, _>>(), Ok(24)); + let v: &[Result<i32, ()>] = &[Ok(1), Err(()), Ok(3), Ok(4)]; + assert_eq!(v.iter().cloned().product::<Result<i32, _>>(), Err(())); +} + +#[test] +fn test_iterator_max() { + let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + assert_eq!(v[..4].iter().cloned().max(), Some(3)); + assert_eq!(v.iter().cloned().max(), Some(10)); + assert_eq!(v[..0].iter().cloned().max(), None); +} + +#[test] +fn test_iterator_min() { + let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; + assert_eq!(v[..4].iter().cloned().min(), Some(0)); + assert_eq!(v.iter().cloned().min(), Some(0)); + assert_eq!(v[..0].iter().cloned().min(), None); +} + +#[test] +fn test_iterator_size_hint() { + let c = (0..).step_by(1); + let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; + let v2 = &[10, 11, 12]; + let vi = v.iter(); + + assert_eq!(c.size_hint(), (usize::MAX, None)); + assert_eq!(vi.clone().size_hint(), (10, Some(10))); + + assert_eq!(c.clone().take(5).size_hint(), (5, Some(5))); + assert_eq!(c.clone().skip(5).size_hint().1, None); + assert_eq!(c.clone().take_while(|_| false).size_hint(), (0, None)); + assert_eq!(c.clone().skip_while(|_| false).size_hint(), (0, None)); + assert_eq!(c.clone().enumerate().size_hint(), (usize::MAX, None)); + assert_eq!(c.clone().chain(vi.clone().cloned()).size_hint(), (usize::MAX, None)); + assert_eq!(c.clone().zip(vi.clone()).size_hint(), (10, Some(10))); + assert_eq!(c.clone().scan(0, |_,_| Some(0)).size_hint(), (0, None)); + assert_eq!(c.clone().filter(|_| false).size_hint(), (0, None)); + assert_eq!(c.clone().map(|_| 0).size_hint(), (usize::MAX, None)); + assert_eq!(c.filter_map(|_| Some(0)).size_hint(), (0, None)); + + assert_eq!(vi.clone().take(5).size_hint(), (5, Some(5))); + assert_eq!(vi.clone().take(12).size_hint(), (10, Some(10))); + assert_eq!(vi.clone().skip(3).size_hint(), (7, Some(7))); + assert_eq!(vi.clone().skip(12).size_hint(), (0, Some(0))); + assert_eq!(vi.clone().take_while(|_| false).size_hint(), (0, Some(10))); + assert_eq!(vi.clone().skip_while(|_| false).size_hint(), (0, Some(10))); + assert_eq!(vi.clone().enumerate().size_hint(), (10, Some(10))); + assert_eq!(vi.clone().chain(v2).size_hint(), (13, Some(13))); + assert_eq!(vi.clone().zip(v2).size_hint(), (3, Some(3))); + assert_eq!(vi.clone().scan(0, |_,_| Some(0)).size_hint(), (0, Some(10))); + assert_eq!(vi.clone().filter(|_| false).size_hint(), (0, Some(10))); + assert_eq!(vi.clone().map(|&i| i+1).size_hint(), (10, Some(10))); + assert_eq!(vi.filter_map(|_| Some(0)).size_hint(), (0, Some(10))); +} + +#[test] +fn test_collect() { + let a = vec![1, 2, 3, 4, 5]; + let b: Vec<isize> = a.iter().cloned().collect(); + assert!(a == b); +} + +#[test] +fn test_all() { + let v: Box<[isize]> = Box::new([1, 2, 3, 4, 5]); + assert!(v.iter().all(|&x| x < 10)); + assert!(!v.iter().all(|&x| x % 2 == 0)); + assert!(!v.iter().all(|&x| x > 100)); + assert!(v[..0].iter().all(|_| panic!())); +} + +#[test] +fn test_any() { + let v: Box<[isize]> = Box::new([1, 2, 3, 4, 5]); + assert!(v.iter().any(|&x| x < 10)); + assert!(v.iter().any(|&x| x % 2 == 0)); + assert!(!v.iter().any(|&x| x > 100)); + assert!(!v[..0].iter().any(|_| panic!())); +} + +#[test] +fn test_find() { + let v: &[isize] = &[1, 3, 9, 27, 103, 14, 11]; + assert_eq!(*v.iter().find(|&&x| x & 1 == 0).unwrap(), 14); + assert_eq!(*v.iter().find(|&&x| x % 3 == 0).unwrap(), 3); + assert!(v.iter().find(|&&x| x % 12 == 0).is_none()); +} + +#[test] +fn test_position() { + let v = &[1, 3, 9, 27, 103, 14, 11]; + assert_eq!(v.iter().position(|x| *x & 1 == 0).unwrap(), 5); + assert_eq!(v.iter().position(|x| *x % 3 == 0).unwrap(), 1); + assert!(v.iter().position(|x| *x % 12 == 0).is_none()); +} + +#[test] +fn test_count() { + let xs = &[1, 2, 2, 1, 5, 9, 0, 2]; + assert_eq!(xs.iter().filter(|x| **x == 2).count(), 3); + assert_eq!(xs.iter().filter(|x| **x == 5).count(), 1); + assert_eq!(xs.iter().filter(|x| **x == 95).count(), 0); +} + +#[test] +fn test_max_by_key() { + let xs: &[isize] = &[-3, 0, 1, 5, -10]; + assert_eq!(*xs.iter().max_by_key(|x| x.abs()).unwrap(), -10); +} + +#[test] +fn test_max_by() { + let xs: &[isize] = &[-3, 0, 1, 5, -10]; + assert_eq!(*xs.iter().max_by(|x, y| x.abs().cmp(&y.abs())).unwrap(), -10); +} + +#[test] +fn test_min_by_key() { + let xs: &[isize] = &[-3, 0, 1, 5, -10]; + assert_eq!(*xs.iter().min_by_key(|x| x.abs()).unwrap(), 0); +} + +#[test] +fn test_min_by() { + let xs: &[isize] = &[-3, 0, 1, 5, -10]; + assert_eq!(*xs.iter().min_by(|x, y| x.abs().cmp(&y.abs())).unwrap(), 0); +} + +#[test] +fn test_by_ref() { + let mut xs = 0..10; + // sum the first five values + let partial_sum = xs.by_ref().take(5).fold(0, |a, b| a + b); + assert_eq!(partial_sum, 10); + assert_eq!(xs.next(), Some(5)); +} + +#[test] +fn test_rev() { + let xs = [2, 4, 6, 8, 10, 12, 14, 16]; + let mut it = xs.iter(); + it.next(); + it.next(); + assert!(it.rev().cloned().collect::<Vec<isize>>() == + vec![16, 14, 12, 10, 8, 6]); +} + +#[test] +fn test_cloned() { + let xs = [2, 4, 6, 8]; + + let mut it = xs.iter().cloned(); + assert_eq!(it.len(), 4); + assert_eq!(it.next(), Some(2)); + assert_eq!(it.len(), 3); + assert_eq!(it.next(), Some(4)); + assert_eq!(it.len(), 2); + assert_eq!(it.next_back(), Some(8)); + assert_eq!(it.len(), 1); + assert_eq!(it.next_back(), Some(6)); + assert_eq!(it.len(), 0); + assert_eq!(it.next_back(), None); +} + +#[test] +fn test_double_ended_map() { + let xs = [1, 2, 3, 4, 5, 6]; + let mut it = xs.iter().map(|&x| x * -1); + assert_eq!(it.next(), Some(-1)); + assert_eq!(it.next(), Some(-2)); + assert_eq!(it.next_back(), Some(-6)); + assert_eq!(it.next_back(), Some(-5)); + assert_eq!(it.next(), Some(-3)); + assert_eq!(it.next_back(), Some(-4)); + assert_eq!(it.next(), None); +} + +#[test] +fn test_double_ended_enumerate() { + let xs = [1, 2, 3, 4, 5, 6]; + let mut it = xs.iter().cloned().enumerate(); + assert_eq!(it.next(), Some((0, 1))); + assert_eq!(it.next(), Some((1, 2))); + assert_eq!(it.next_back(), Some((5, 6))); + assert_eq!(it.next_back(), Some((4, 5))); + assert_eq!(it.next_back(), Some((3, 4))); + assert_eq!(it.next_back(), Some((2, 3))); + assert_eq!(it.next(), None); +} + +#[test] +fn test_double_ended_zip() { + let xs = [1, 2, 3, 4, 5, 6]; + let ys = [1, 2, 3, 7]; + let a = xs.iter().cloned(); + let b = ys.iter().cloned(); + let mut it = a.zip(b); + assert_eq!(it.next(), Some((1, 1))); + assert_eq!(it.next(), Some((2, 2))); + assert_eq!(it.next_back(), Some((4, 7))); + assert_eq!(it.next_back(), Some((3, 3))); + assert_eq!(it.next(), None); +} + +#[test] +fn test_double_ended_filter() { + let xs = [1, 2, 3, 4, 5, 6]; + let mut it = xs.iter().filter(|&x| *x & 1 == 0); + assert_eq!(it.next_back().unwrap(), &6); + assert_eq!(it.next_back().unwrap(), &4); + assert_eq!(it.next().unwrap(), &2); + assert_eq!(it.next_back(), None); +} + +#[test] +fn test_double_ended_filter_map() { + let xs = [1, 2, 3, 4, 5, 6]; + let mut it = xs.iter().filter_map(|&x| if x & 1 == 0 { Some(x * 2) } else { None }); + assert_eq!(it.next_back().unwrap(), 12); + assert_eq!(it.next_back().unwrap(), 8); + assert_eq!(it.next().unwrap(), 4); + assert_eq!(it.next_back(), None); +} + +#[test] +fn test_double_ended_chain() { + let xs = [1, 2, 3, 4, 5]; + let ys = [7, 9, 11]; + let mut it = xs.iter().chain(&ys).rev(); + assert_eq!(it.next().unwrap(), &11); + assert_eq!(it.next().unwrap(), &9); + assert_eq!(it.next_back().unwrap(), &1); + assert_eq!(it.next_back().unwrap(), &2); + assert_eq!(it.next_back().unwrap(), &3); + assert_eq!(it.next_back().unwrap(), &4); + assert_eq!(it.next_back().unwrap(), &5); + assert_eq!(it.next_back().unwrap(), &7); + assert_eq!(it.next_back(), None); + + + // test that .chain() is well behaved with an unfused iterator + struct CrazyIterator(bool); + impl CrazyIterator { fn new() -> CrazyIterator { CrazyIterator(false) } } + impl Iterator for CrazyIterator { + type Item = i32; + fn next(&mut self) -> Option<i32> { + if self.0 { Some(99) } else { self.0 = true; None } + } + } + + impl DoubleEndedIterator for CrazyIterator { + fn next_back(&mut self) -> Option<i32> { + self.next() + } + } + + assert_eq!(CrazyIterator::new().chain(0..10).rev().last(), Some(0)); + assert!((0..10).chain(CrazyIterator::new()).rev().any(|i| i == 0)); +} + +#[test] +fn test_rposition() { + fn f(xy: &(isize, char)) -> bool { let (_x, y) = *xy; y == 'b' } + fn g(xy: &(isize, char)) -> bool { let (_x, y) = *xy; y == 'd' } + let v = [(0, 'a'), (1, 'b'), (2, 'c'), (3, 'b')]; + + assert_eq!(v.iter().rposition(f), Some(3)); + assert!(v.iter().rposition(g).is_none()); +} + +#[test] +#[should_panic] +fn test_rposition_panic() { + let v: [(Box<_>, Box<_>); 4] = + [(box 0, box 0), (box 0, box 0), + (box 0, box 0), (box 0, box 0)]; + let mut i = 0; + v.iter().rposition(|_elt| { + if i == 2 { + panic!() + } + i += 1; + false + }); +} + + +#[test] +fn test_double_ended_flat_map() { + let u = [0,1]; + let v = [5,6,7,8]; + let mut it = u.iter().flat_map(|x| &v[*x..v.len()]); + assert_eq!(it.next_back().unwrap(), &8); + assert_eq!(it.next().unwrap(), &5); + assert_eq!(it.next_back().unwrap(), &7); + assert_eq!(it.next_back().unwrap(), &6); + assert_eq!(it.next_back().unwrap(), &8); + assert_eq!(it.next().unwrap(), &6); + assert_eq!(it.next_back().unwrap(), &7); + assert_eq!(it.next_back(), None); + assert_eq!(it.next(), None); + assert_eq!(it.next_back(), None); +} + +#[test] +fn test_double_ended_range() { + assert_eq!((11..14).rev().collect::<Vec<_>>(), [13, 12, 11]); + for _ in (10..0).rev() { + panic!("unreachable"); + } + + assert_eq!((11..14).rev().collect::<Vec<_>>(), [13, 12, 11]); + for _ in (10..0).rev() { + panic!("unreachable"); + } +} + +#[test] +fn test_range() { + assert_eq!((0..5).collect::<Vec<_>>(), [0, 1, 2, 3, 4]); + assert_eq!((-10..-1).collect::<Vec<_>>(), [-10, -9, -8, -7, -6, -5, -4, -3, -2]); + assert_eq!((0..5).rev().collect::<Vec<_>>(), [4, 3, 2, 1, 0]); + assert_eq!((200..-5).count(), 0); + assert_eq!((200..-5).rev().count(), 0); + assert_eq!((200..200).count(), 0); + assert_eq!((200..200).rev().count(), 0); + + assert_eq!((0..100).size_hint(), (100, Some(100))); + // this test is only meaningful when sizeof usize < sizeof u64 + assert_eq!((usize::MAX - 1..usize::MAX).size_hint(), (1, Some(1))); + assert_eq!((-10..-1).size_hint(), (9, Some(9))); + assert_eq!((-1..-10).size_hint(), (0, Some(0))); + + assert_eq!((-70..58).size_hint(), (128, Some(128))); + assert_eq!((-128..127).size_hint(), (255, Some(255))); + assert_eq!((-2..isize::MAX).size_hint(), + (isize::MAX as usize + 2, Some(isize::MAX as usize + 2))); +} + +#[test] +fn test_range_step() { + assert_eq!((0..20).step_by(5).collect::<Vec<isize>>(), [0, 5, 10, 15]); + assert_eq!((20..0).step_by(-5).collect::<Vec<isize>>(), [20, 15, 10, 5]); + assert_eq!((20..0).step_by(-6).collect::<Vec<isize>>(), [20, 14, 8, 2]); + assert_eq!((200..255).step_by(50).collect::<Vec<u8>>(), [200, 250]); + assert_eq!((200..-5).step_by(1).collect::<Vec<isize>>(), []); + assert_eq!((200..200).step_by(1).collect::<Vec<isize>>(), []); + + assert_eq!((0..20).step_by(1).size_hint(), (20, Some(20))); + assert_eq!((0..20).step_by(21).size_hint(), (1, Some(1))); + assert_eq!((0..20).step_by(5).size_hint(), (4, Some(4))); + assert_eq!((20..0).step_by(-5).size_hint(), (4, Some(4))); + assert_eq!((20..0).step_by(-6).size_hint(), (4, Some(4))); + assert_eq!((20..-5).step_by(1).size_hint(), (0, Some(0))); + assert_eq!((20..20).step_by(1).size_hint(), (0, Some(0))); + assert_eq!((0..1).step_by(0).size_hint(), (0, None)); + assert_eq!((i8::MAX..i8::MIN).step_by(i8::MIN).size_hint(), (2, Some(2))); + assert_eq!((i16::MIN..i16::MAX).step_by(i16::MAX).size_hint(), (3, Some(3))); + assert_eq!((isize::MIN..isize::MAX).step_by(1).size_hint(), (usize::MAX, Some(usize::MAX))); +} + +#[test] +fn test_repeat() { + let mut it = repeat(42); + assert_eq!(it.next(), Some(42)); + assert_eq!(it.next(), Some(42)); + assert_eq!(it.next(), Some(42)); +} + +#[test] +fn test_fuse() { + let mut it = 0..3; + assert_eq!(it.len(), 3); + assert_eq!(it.next(), Some(0)); + assert_eq!(it.len(), 2); + assert_eq!(it.next(), Some(1)); + assert_eq!(it.len(), 1); + assert_eq!(it.next(), Some(2)); + assert_eq!(it.len(), 0); + assert_eq!(it.next(), None); + assert_eq!(it.len(), 0); + assert_eq!(it.next(), None); + assert_eq!(it.len(), 0); + assert_eq!(it.next(), None); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_fuse_nth() { + let xs = [0, 1, 2]; + let mut it = xs.iter(); + + assert_eq!(it.len(), 3); + assert_eq!(it.nth(2), Some(&2)); + assert_eq!(it.len(), 0); + assert_eq!(it.nth(2), None); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_fuse_last() { + let xs = [0, 1, 2]; + let it = xs.iter(); + + assert_eq!(it.len(), 3); + assert_eq!(it.last(), Some(&2)); +} + +#[test] +fn test_fuse_count() { + let xs = [0, 1, 2]; + let it = xs.iter(); + + assert_eq!(it.len(), 3); + assert_eq!(it.count(), 3); + // Can't check len now because count consumes. +} + +#[test] +fn test_once() { + let mut it = once(42); + assert_eq!(it.next(), Some(42)); + assert_eq!(it.next(), None); +} + +#[test] +fn test_empty() { + let mut it = empty::<i32>(); + assert_eq!(it.next(), None); +} + +#[test] +fn test_chain_fold() { + let xs = [1, 2, 3]; + let ys = [1, 2, 0]; + + let mut iter = xs.iter().chain(&ys); + iter.next(); + let mut result = Vec::new(); + iter.fold((), |(), &elt| result.push(elt)); + assert_eq!(&[2, 3, 1, 2, 0], &result[..]); +} + |