mirror of
https://gitlab.torproject.org/tpo/core/tor.git
synced 2024-11-10 21:23:58 +01:00
rust/protover: add ProtoSet::and_not_in()
This is a way more efficient version of retain().
This commit is contained in:
parent
281854bab7
commit
578f7326ed
@ -4,6 +4,8 @@
|
||||
|
||||
//! Sets for lazily storing ordered, non-overlapping ranges of integers.
|
||||
|
||||
use std::cmp;
|
||||
use std::iter;
|
||||
use std::slice;
|
||||
use std::str::FromStr;
|
||||
use std::u32;
|
||||
@ -269,6 +271,57 @@ impl ProtoSet {
|
||||
expanded.retain(f);
|
||||
*self = expanded.into();
|
||||
}
|
||||
|
||||
/// Returns all the `Version`s in `self` which are not also in the `other`
|
||||
/// `ProtoSet`.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// ```
|
||||
/// # use protover::errors::ProtoverError;
|
||||
/// use protover::protoset::ProtoSet;
|
||||
///
|
||||
/// # fn do_test() -> Result<bool, ProtoverError> {
|
||||
/// let protoset: ProtoSet = "1,3-6,10-12,15-16".parse()?;
|
||||
/// let other: ProtoSet = "2,5-7,9-11,14-20".parse()?;
|
||||
///
|
||||
/// let subset: ProtoSet = protoset.and_not_in(&other);
|
||||
///
|
||||
/// assert_eq!(subset.expand(), vec![1, 3, 4, 12]);
|
||||
/// #
|
||||
/// # Ok(true)
|
||||
/// # }
|
||||
/// # fn main() { do_test(); } // wrap the test so we can use the ? operator
|
||||
/// ```
|
||||
pub fn and_not_in(&self, other: &Self) -> Self {
|
||||
if self.is_empty() || other.is_empty() {
|
||||
return self.clone();
|
||||
}
|
||||
|
||||
let pairs = self.iter().flat_map(|&(lo, hi)| {
|
||||
let the_end = (hi + 1, hi + 1); // special case to mark the end of the range.
|
||||
let excluded_ranges = other
|
||||
.iter()
|
||||
.cloned() // have to be owned tuples, to match iter::once(the_end).
|
||||
.skip_while(move|&(_, hi2)| hi2 < lo) // skip the non-overlapping ranges.
|
||||
.take_while(move|&(lo2, _)| lo2 <= hi) // take all the overlapping ones.
|
||||
.chain(iter::once(the_end));
|
||||
|
||||
let mut nextlo = lo;
|
||||
excluded_ranges.filter_map(move |(excluded_lo, excluded_hi)| {
|
||||
let pair = if nextlo < excluded_lo {
|
||||
Some((nextlo, excluded_lo - 1))
|
||||
} else {
|
||||
None
|
||||
};
|
||||
nextlo = cmp::min(excluded_hi, u32::MAX - 1) + 1;
|
||||
pair
|
||||
})
|
||||
});
|
||||
|
||||
let pairs = pairs.collect();
|
||||
ProtoSet::is_ok(ProtoSet{ pairs }).expect("should be already sorted")
|
||||
}
|
||||
}
|
||||
|
||||
impl FromStr for ProtoSet {
|
||||
|
Loading…
Reference in New Issue
Block a user