Skip to content

Fix meet_into keeping its own focus value when the meet is the source's #179

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
luketpeterson merged 2 commits into from
Nov 5, 2026
Merged

Fix meet_into keeping its own focus value when the meet is the source's #179

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7faa9ab
Fix meet_into keeping its own focus value when the meet is the source's
imlvts Oct 27, 2026
f725487
Merge branch 'master' into fix/meet-into-focus-value
imlvts Nov 4, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 17 additions & 1 deletion src/write_zipper.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2136,7 +2136,9 @@ impl <'a, 'path, V: Clone + Send + Sync + Unpin, A: Allocator + 'a> WriteZipperC
let new_status = match self_val.pmeet(src_val) {
AlgebraicResult::Element(new_val) => {self.set_val(new_val); AlgebraicStatus::Element },
AlgebraicResult::None => {self.remove_val(prune); AlgebraicStatus::None },
AlgebraicResult::Identity(_) => { AlgebraicStatus::Identity }
AlgebraicResult::Identity(mask) if mask & SELF_IDENT > 0 => { AlgebraicStatus::Identity },
//The meet is the source's value
AlgebraicResult::Identity(_) => { self.set_val(src_val.clone()); AlgebraicStatus::Element },
};
(new_status, false)
},
Expand Down Expand Up @@ -8310,6 +8312,20 @@ mod tests {
assert!(map.into_write_zipper(b"missing").fork_read_zipper().is_none());
}

/// `meet_into` must store the meet of the focus values even when it equals the source's value
/// (`pmeet` reports that as `Identity(COUNTER_IDENT)`)
#[test]
fn write_zipper_meet_into_focus_value_from_source() {
let mut dst = PathMap::<ByteMask>::new();
dst.set_val_at(b"", ByteMask::from_iter([1u8, 2]));
let mut src = PathMap::<ByteMask>::new();
src.set_val_at(b"", ByteMask::from_iter([2u8]));
let status = dst.write_zipper().meet_into(&src.read_zipper(), false);
assert_eq!(status, AlgebraicStatus::Element);
assert_eq!(dst.val_at(b""), Some(&ByteMask::from_iter([2u8])));
assert_eq!(dst.val_at(b""), src.meet(&dst).val_at(b""));
}

/// `take_map` of a focus holding only a value returns a map with that value at its root, and the
/// map must take writes below the root. The empty node left at the focus used to come along,
/// and the first write panicked on it ("make_unique on an empty sentinel node")
Expand Down