Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/span/src/map.rs')
| -rw-r--r-- | crates/span/src/map.rs | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/crates/span/src/map.rs b/crates/span/src/map.rs index 2680e5036c..f80de05ec6 100644 --- a/crates/span/src/map.rs +++ b/crates/span/src/map.rs @@ -13,6 +13,7 @@ use crate::{ /// Maps absolute text ranges for the corresponding file to the relevant span data. #[derive(Debug, PartialEq, Eq, Clone, Hash)] pub struct SpanMap<S> { + /// The offset stored here is the *end* of the node. spans: Vec<(TextSize, SpanData<S>)>, /// Index of the matched macro arm on successful expansion for declarative macros. // FIXME: Does it make sense to have this here? @@ -109,11 +110,32 @@ where /// /// The length of the replacement node needs to be `other_size`. pub fn merge(&mut self, other_range: TextRange, other_size: TextSize, other: &SpanMap<S>) { + // I find the following diagram helpful to illustrate the bounds and why we use `<` or `<=`: + // -------------------------------------------------------------------- + // 1 3 5 6 7 10 11 <-- offsets we store + // 0-1 1-3 3-5 5-6 6-7 7-10 10-11 <-- ranges these offsets refer to + // 3 .. 7 <-- other_range + // 3-5 5-6 6-7 <-- ranges we replace (len = 7-3 = 4) + // ^^^^^^^^^^^ ^^^^^^^^^^ + // remove shift + // 2 3 5 9 <-- offsets we insert + // 0-2 2-3 3-5 5-9 <-- ranges we insert (other_size = 9-0 = 9) + // ------------------------------------ + // 1 3 + // 0-1 1-3 <-- these remain intact + // 5 6 8 12 + // 3-5 5-6 6-8 8-12 <-- we shift these by other_range.start() and insert them + // 15 16 + // 12-15 15-16 <-- we shift these by other_size-other_range.len() = 9-4 = 5 + // ------------------------------------ + // 1 3 5 6 8 12 15 16 <-- final offsets we store + // 0-1 1-3 3-5 5-6 6-8 8-12 12-15 15-16 <-- final ranges + self.spans.retain_mut(|(offset, _)| { - if other_range.contains(*offset) { + if other_range.start() < *offset && *offset <= other_range.end() { false } else { - if *offset >= other_range.end() { + if *offset > other_range.end() { *offset += other_size; *offset -= other_range.len(); } |