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use std::{fmt, iter::Iterator};
use crate::errors::*;
/// Assert that the elements of the given iterables are equal and `Panics` when when not.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_iter_eq(vec![1, 2, 3].into_iter(), vec![1, 2, 3].into_iter());
/// ```
pub fn assert_iter_eq<T, U>(x: T, y: U)
where
T: IntoIterator,
U: IntoIterator,
T::Item: fmt::Debug + PartialEq<U::Item>,
U::Item: fmt::Debug,
{
let mut x = x.into_iter();
let mut y = y.into_iter();
loop {
let (a, b) = (x.next(), y.next());
if a.is_none() && b.is_none() {
return;
}
let equal = match (&a, &b) {
// Compare the two items
(Some(a), Some(b)) => a == b,
// Different lengths
_ => false,
};
assert!(equal, "Iterators not equal {:?} != {:?}", a, b);
}
}
/// Provides extensions for the [`Iterator`] trait
pub trait IteratorExt: Iterator {
/// Consume the entire iterator eagerly up until but not including the last call to
/// get None. Allows caller to then call next and get None.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!(vec![0, 1, 2].into_iter().consume().next(), None);
/// ```
fn consume(self) -> Self
where
Self: Sized;
/// Drop the first `n` items if positive from the iterator eagerly and then return the
/// iterator. Drop the last `|n|` items if negative from the iterator eagerly and then
/// return the iterator.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_iter_eq(vec![1, 2, 3].into_iter().drop(1), vec![2, 3]);
/// assert_iter_eq(vec![1, 2, 3].into_iter().drop(-1), vec![1, 2]);
/// ```
fn drop(self, n: isize) -> Self
where
Self: Sized,
Self: DoubleEndedIterator;
/// Returns the first element of the iterator. Alias to nth(0).
///
/// `first()` will return [`None`] if `n` is greater than or equal to the length of the
/// iterator.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!((0..10).filter(|&x| x == 2).first().unwrap(), 2);
/// ```
fn first(self) -> Option<Self::Item>
where
Self: Sized;
/// If the iterator yields at least one element, the first element will be returned,
/// otherwise an error will be returned.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!((0..10).filter(|&x| x == 2).first().unwrap(), 2);
/// ```
fn first_result(self) -> RvResult<Self::Item>
where
Self: Sized;
/// If the iterator yields at least one element, the last element will be returned,
/// otherwise an error will be returned.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!((0..10).filter(|&x| x == 2).last().unwrap(), 2);
/// ```
fn last_result(self) -> RvResult<Self::Item>
where
Self: Sized;
/// If the iterator yields a single element, that element will be returned, otherwise an
/// error will be returned.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!((0..10).filter(|&x| x == 2).single().unwrap(), 2);
/// ```
fn single(self) -> RvResult<Self::Item>
where
Self: Sized;
/// Slice returns this iterator eagerly to only iterate over the range of elements called out
/// by the given indices. Allows for negative notation.
///
/// Note this operation uses count() to determine length which means cost O(n) out of the gate.
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// let mut iter = vec![0, 1, 2].into_iter().slice(0, 0);
/// assert_eq!(iter.next(), Some(0));
/// assert_eq!(iter.next(), None);
///
/// let mut iter = vec![0, 1, 2].into_iter().slice(-1, -1);
/// assert_eq!(iter.next(), Some(2));
/// assert_eq!(iter.next(), None);
///
/// let mut iter = vec![0, 1, 2].into_iter().slice(-2, -1);
/// assert_eq!(iter.next(), Some(1));
/// assert_eq!(iter.next(), Some(2));
/// assert_eq!(iter.next(), None);
/// ```
fn slice(self, left: isize, right: isize) -> Self
where
Self: Sized,
Self: Clone,
Self: DoubleEndedIterator;
/// If the iterator yields at least one element, true will be returned else false
///
/// # Examples
/// ```
/// use rivia::prelude::*;
///
/// assert_eq!((0..10).filter(|&x| x == 2).some(), true);
/// ```
fn some(self) -> bool
where
Self: Sized;
}
impl<T: ?Sized> IteratorExt for T
where
T: Iterator,
{
#[allow(clippy::all)]
fn consume(mut self) -> Self
where
Self: Sized,
{
let mut iter = (&mut self).peekable();
while let Some(_) = iter.next() {}
self
}
fn drop(mut self, n: isize) -> Self
where
Self: Sized,
Self: DoubleEndedIterator,
{
// Drop left
if n > 0 {
self.nth(n as usize - 1);
}
// Drop right
if n < 0 {
(&mut self).rev().nth(n.unsigned_abs() - 1);
}
self
}
fn first(mut self) -> Option<Self::Item>
where
Self: Sized,
{
self.next()
}
fn first_result(mut self) -> RvResult<Self::Item>
where
Self: Sized,
{
match self.next() {
Some(first) => Ok(first),
None => Err(IterError::item_not_found().into()),
}
}
fn last_result(self) -> RvResult<Self::Item>
where
Self: Sized,
{
match self.last() {
Some(item) => Ok(item),
None => Err(IterError::item_not_found().into()),
}
}
fn single(mut self) -> RvResult<Self::Item>
where
Self: Sized,
{
match self.next() {
Some(item) => match self.next() {
Some(_) => Err(IterError::multiple_items_found().into()),
None => Ok(item),
},
None => Err(IterError::item_not_found().into()),
}
}
fn slice(mut self, left: isize, right: isize) -> Self
where
Self: Sized,
Self: Clone,
Self: DoubleEndedIterator,
{
// Convert left to postive notation and trim
let (mut l, mut r): (usize, usize) = (left as usize, 0);
let len = (self.clone()).count() as isize;
if left < 0 {
l = (len + left) as usize;
}
if l > 0 {
self.nth(l - 1);
}
// Convert right to negative notation and trim.
// Offset to have inclusive behavior.
if right > 0 && right < len {
r = (right - len + 1).unsigned_abs();
} else if right < 0 && right.abs() <= len {
r = (right.abs() - 1).unsigned_abs();
} else if right < 0 {
r = len as usize;
}
if r > 0 {
(&mut self).rev().nth(r - 1);
}
// Get first or last
if left == 0 && right == 0 {
let i = len - 2;
if i > 0 {
(&mut self).rev().nth(i as usize);
}
}
self
}
fn some(mut self) -> bool
where
Self: Sized,
{
self.next().is_some()
}
}
#[cfg(test)]
mod tests {
use std::ffi::OsStr;
use std::path::{Component, PathBuf};
use crate::core::*;
use crate::errors::*;
#[test]
fn test_slice() {
// Both negative
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(-1, -5).next(), None); // right out of bounds negatively consumes all
assert_iter_eq(vec![0, 1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(-4, -1)); // get all
assert_iter_eq(vec![0, 1, 2], vec![0, 1, 2, 3].into_iter().slice(-4, -2)); // get all but last
assert_iter_eq(vec![0, 1], vec![0, 1, 2, 3].into_iter().slice(-4, -3)); // get all but last 2
assert_iter_eq(vec![3], vec![0, 1, 2, 3].into_iter().slice(-1, -1)); // get last
assert_iter_eq(vec![2], vec![0, 1, 2, 3].into_iter().slice(-2, -2)); // get index 2
assert_iter_eq(vec![1], vec![0, 1, 2, 3].into_iter().slice(-3, -3)); // get index 1
assert_iter_eq(vec![0], vec![0, 1, 2, 3].into_iter().slice(-4, -4)); // get first
assert_iter_eq(vec![1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(-3, -1)); // get all but first
assert_iter_eq(vec![1, 2], vec![0, 1, 2, 3].into_iter().slice(-3, -2)); // get middle
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(-1, -2).next(), None); // mutually exclusive consumes everything
// Both positive
assert_iter_eq(vec![0, 1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(0, 4)); // right out of bounds positively gets moved in
assert_iter_eq(vec![0, 1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(0, 3)); // get all
assert_iter_eq(vec![0, 1, 2], vec![0, 1, 2, 3].into_iter().slice(0, 2)); // get all but last
assert_iter_eq(vec![0, 1], vec![0, 1, 2, 3].into_iter().slice(0, 1)); // get all but last 2
assert_iter_eq(vec![3], vec![0, 1, 2, 3].into_iter().slice(3, 3)); // get last
assert_iter_eq(vec![2], vec![0, 1, 2, 3].into_iter().slice(2, 2)); // get index 2
assert_iter_eq(vec![1], vec![0, 1, 2, 3].into_iter().slice(1, 1)); // get index 1
assert_iter_eq(vec![0], vec![0, 1, 2, 3].into_iter().slice(0, 0)); // get first
assert_iter_eq(vec![1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(1, 3)); // get all but first
assert_iter_eq(vec![1, 2], vec![0, 1, 2, 3].into_iter().slice(1, 2)); // get middle
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(3, 2).next(), None); // mutually exclusive consumes everything
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(4, 3).next(), None); // left out of bounds consumes everything
// Left postive and right negative
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(0, -5).next(), None); // right out of bounds negatively consumes all
assert_iter_eq(vec![0, 1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(0, -1)); // get all
assert_iter_eq(vec![0, 1, 2], vec![0, 1, 2, 3].into_iter().slice(0, -2)); // get all but last
assert_iter_eq(vec![0, 1], vec![0, 1, 2, 3].into_iter().slice(0, -3)); // get all but last 2
assert_iter_eq(vec![3], vec![0, 1, 2, 3].into_iter().slice(3, -1)); // get last
assert_iter_eq(vec![2], vec![0, 1, 2, 3].into_iter().slice(2, -2)); // get index 2
assert_iter_eq(vec![1], vec![0, 1, 2, 3].into_iter().slice(1, -3)); // get index 1
assert_iter_eq(vec![0], vec![0, 1, 2, 3].into_iter().slice(0, -4)); // get first
assert_iter_eq(vec![1, 2, 3], vec![0, 1, 2, 3].into_iter().slice(1, -1)); // get all but first
assert_iter_eq(vec![1, 2], vec![0, 1, 2, 3].into_iter().slice(1, -2)); // get middle
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(3, -2).next(), None); // mutually exclusive consumes everything
assert_eq!(vec![0, 1, 2, 3].into_iter().slice(4, -1).next(), None); // left out of bounds
// consumes everything
}
#[test]
fn test_consume() {
assert_eq!(vec![0].into_iter().nth(0), Some(0));
assert_eq!(vec![0, 1, 2].into_iter().consume().nth(0), None);
}
#[test]
fn test_drop() {
// Start
assert_iter_eq(vec![2, 3], vec![1, 2, 3].into_iter().drop(1));
assert_iter_eq(PathBuf::from("bar").components(), PathBuf::from("foo/bar").components().drop(1));
assert_iter_eq(PathBuf::from("bar").components(), PathBuf::from("/foo/bar").components().drop(2));
// End
assert_iter_eq(vec![1, 2], vec![1, 2, 3].into_iter().drop(-1));
assert_eq!(1, vec![1, 2, 3].into_iter().drop(-1).next().unwrap());
assert_iter_eq(PathBuf::from("foo").components(), PathBuf::from("foo/bar").components().drop(-1));
assert_iter_eq(PathBuf::from("/").components(), PathBuf::from("/foo/bar").components().drop(-2));
}
#[test]
fn test_eq() {
assert_iter_eq(vec![1, 2], vec![1, 2]);
assert!(std::panic::catch_unwind(|| assert_iter_eq(vec![1, 2], vec![1])).is_err());
assert!(std::panic::catch_unwind(|| assert_iter_eq(vec![1, 2], vec![1, 3])).is_err());
assert_iter_eq(PathBuf::from("foo/bar").components(), PathBuf::from("foo/bar").components());
assert!(std::panic::catch_unwind(|| assert_iter_eq(
PathBuf::from("foo/bar").components(),
PathBuf::from("bar").components()
))
.is_err());
}
#[test]
fn test_first() {
assert_eq!(Component::Normal(OsStr::new("foo")), PathBuf::from("foo/bar").components().first().unwrap());
assert_ne!(Component::Normal(OsStr::new("bar")), PathBuf::from("foo/bar").components().first().unwrap());
}
#[test]
fn test_first_result() {
assert_eq!(
Component::Normal(OsStr::new("foo")),
PathBuf::from("foo/bar").components().first_result().unwrap()
);
assert_ne!(
Component::Normal(OsStr::new("bar")),
PathBuf::from("foo/bar").components().first_result().unwrap()
);
}
#[test]
fn test_last_result() {
assert_eq!(
Component::Normal(OsStr::new("bar")),
PathBuf::from("foo/bar").components().last_result().unwrap()
);
assert_ne!(
Component::Normal(OsStr::new("foo")),
PathBuf::from("foo/bar").components().last_result().unwrap()
);
}
#[test]
fn test_single() {
assert_eq!((0..10).filter(|&x| x == 2).single().unwrap(), 2);
assert_eq!(
(0..10).filter(|&x| x > 2).single().unwrap_err().downcast_ref::<IterError>(),
Some(&IterError::multiple_items_found())
);
assert_eq!(
(0..10).filter(|&x| x > 2 && x < 5).single().unwrap_err().downcast_ref::<IterError>(),
Some(&IterError::multiple_items_found())
);
}
#[test]
fn test_some() {
assert_eq!((0..10).filter(|&x| x == 2).some(), true);
assert_eq!((0..10).filter(|&x| x == 11).some(), false);
}
}