just/src/range_ext.rs

83 lines
2.0 KiB
Rust

use super::*;
pub(crate) trait RangeExt<T> {
fn range_contains(&self, i: &T) -> bool;
fn display(&self) -> DisplayRange<&Self> {
DisplayRange(self)
}
}
pub(crate) struct DisplayRange<T>(T);
impl Display for DisplayRange<&Range<usize>> {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
if self.0.start == self.0.end {
write!(f, "{}", self.0.start)?;
} else if self.0.end == usize::MAX {
write!(f, "{} or more", self.0.start)?;
} else {
write!(f, "{} to {}", self.0.start, self.0.end)?;
}
Ok(())
}
}
impl<T> RangeExt<T> for Range<T>
where
T: PartialOrd,
{
fn range_contains(&self, i: &T) -> bool {
i >= &self.start && i < &self.end
}
}
impl<T> RangeExt<T> for RangeInclusive<T>
where
T: PartialOrd,
{
fn range_contains(&self, i: &T) -> bool {
i >= self.start() && i <= self.end()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn exclusive() {
assert!(!(0..0).range_contains(&0));
assert!(!(0..0).range_contains(&0));
assert!(!(1..10).range_contains(&0));
assert!(!(1..10).range_contains(&10));
assert!(!(1..10).range_contains(&0));
assert!(!(1..10).range_contains(&10));
assert!((0..1).range_contains(&0));
assert!((0..1).range_contains(&0));
assert!((10..20).range_contains(&15));
assert!((10..20).range_contains(&15));
}
#[test]
fn inclusive() {
assert!(!(0..=10).range_contains(&11));
assert!(!(1..=10).range_contains(&0));
assert!(!(5..=10).range_contains(&4));
assert!((0..=0).range_contains(&0));
assert!((0..=1).range_contains(&0));
assert!((0..=10).range_contains(&0));
assert!((0..=10).range_contains(&10));
assert!((0..=10).range_contains(&7));
assert!((1..=10).range_contains(&10));
assert!((10..=20).range_contains(&15));
}
#[test]
fn display() {
assert_eq!((1..1).display().to_string(), "1");
assert_eq!((1..2).display().to_string(), "1 to 2");
assert_eq!((1..usize::MAX).display().to_string(), "1 or more");
}
}