1 files changed, 55 insertions, 29 deletions

diff --git a/src/parse/regex/byte_range.rs b/src/parse/regex/byte_range.rs
index 86b2c2b..0151f0c 100644
--- a/src/parse/regex/byte_range.rs
+++ b/src/parse/regex/byte_range.rs
@@ -16,7 +16,7 @@ impl From<RangeInclusive<u8>> for ByteRange {
 
 impl ByteRange {
     pub fn new_range(from: u8, to: u8) -> Self {
-        assert!(from <= to);
+        assert!(from <= to, "{from} <= {to}");
         Self { from, to }
     }
 
@@ -33,42 +33,68 @@ impl ByteRange {
         self.from.max(other.from) <= self.to.min(other.to)
     }
 
-    pub fn non_overlapping(sets: Vec<ByteRange>) -> Vec<ByteRange> {
-        let begins = sets.iter().map(|cs| (cs.from, 1));
-        let ends = sets.iter().map(|cs| (cs.to, 2));
-        let mut edges: Vec<_> = begins.chain(ends).collect();
-        edges.sort();
-        edges.iter_mut().for_each(|c| {
-            if c.1 == 2 {
-                c.1 = -1;
+    pub fn split_to_disjoint(ranges: Vec<ByteRange>) -> Vec<ByteRange> {
+        if ranges.is_empty() {
+            return vec![];
+        }
+    
+        let mut points: Vec<u8> = Vec::new();
+        for r in &ranges {
+            points.push(r.from);
+            if r.to != u8::MAX {
+                points.push(r.to + 1);
             }
-        });
-
-        let mut last = None;
-        let mut depth = 0;
+        }
+    
+        points.sort_unstable();
+        points.dedup();
+    
         let mut out = Vec::new();
-
-        for (mut loc, delta) in edges {
-            if let Some(last) = last
-                && last <= loc
-            {
-                out.push(ByteRange::new_range(last, loc));
-                loc += 1;
+    
+        for window in points.windows(2) {
+            let start = window[0];
+            let end_exclusive = window[1];
+    
+            if start >= end_exclusive {
+                continue;
             }
-
-            depth += delta;
-
-            if depth > 0 {
-                last = Some(loc);
-            } else {
-                last = None;
+    
+            let mut active = false;
+    
+            for r in &ranges {
+                if r.from <= start && start <= r.to {
+                    active = true;
+                    break;
+                }
+            }
+    
+            if active {
+                out.push(ByteRange {
+                    from: start,
+                    to: end_exclusive - 1,
+                });
             }
         }
-
+    
         out
     }
 }
 
+#[test]
+fn byterange_test() {
+    assert_eq!(
+        ByteRange::split_to_disjoint(vec![
+            ByteRange::new_range(b'a', b'z'),
+            ByteRange::new_single(b'm')
+        ]),
+        vec![
+            ByteRange::new_range(b'a', b'l'),
+            ByteRange::new_single(b'm'),
+            ByteRange::new_range(b'n', b'z'),
+        ]
+    );
+}
+
 impl std::fmt::Debug for ByteRange {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         if self.from == self.to {
@@ -106,7 +132,7 @@ mod non_overlapping_tests {
 
     fn run(ranges: Vec<RangeInclusive<u8>>) {
         let ranges1: Vec<ByteRange> = ranges.into_iter().map(Into::into).collect();
-        let ranges2 = ByteRange::non_overlapping(ranges1.clone());
+        let ranges2 = ByteRange::split_to_disjoint(ranges1.clone());
 
         let r1 = |c| ranges1.iter().any(|cr| cr.contains(c));
         let r2 = |c| ranges2.iter().any(|cr| cr.contains(c));