Struct RunTextChange 

pub struct RunTextChange {
    pub run: u32,
    pub start: u32,
    pub end: u32,
    pub inserted: u32,
}

Fields

run: u32

The run (GraphemeClusterId::source_run) whose text changed.

start: u32

First changed byte of the old text.

end: u32

One past the last changed byte of the old text (== start for a pure insert).

inserted: u32

How many bytes replaced start..end.

Implementations

impl RunTextChange

pub fn between(run: u32, old: &str, new: &str) -> Option<Self>

The smallest change between two versions of one run’s text: the common prefix and the common suffix are unchanged, what lies between was replaced. None when the texts are identical.

Byte-level, then backed off to char boundaries on BOTH sides so a change never starts or ends inside a multi-byte character. When the inserted text repeats its neighbour (aa -> aaa) the position is ambiguous by nature; the prefix wins, which puts the change AFTER the existing copy - the only carets that can tell the difference sit between identical characters.

pub fn transform(&self, byte: u32) -> u32

Where a caret that sat at byte of the OLD text sits in the new one.

The user’s rule (2026-09-03): a caret is anchored at a LOGICAL position, so a change entirely before it shifts it by the delta, a change entirely after it leaves it alone, and a change that spans it collapses it to the change’s start - the only position that still exists. A caret AT a pure insert’s position counts as after it: it is attached to the character that follows, and that character moved.

Trait Implementations

impl Clone for RunTextChange

fn clone(&self) -> RunTextChange

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for RunTextChange

impl Debug for RunTextChange

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for RunTextChange

impl Hash for RunTextChange

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for RunTextChange

fn eq(&self, other: &RunTextChange) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for RunTextChange