Struct StepIndex 

pub struct StepIndex { /* private fields */ }

A document’s history read once and kept up to date: its changes in causal order and what each one was to the steps of its author. A change’s kind never changes, so it is read once; new changes are read as they arrive.

Implementations

impl StepIndex

pub fn refresh(&mut self, doc: &AutoCommit)

Bring the index up to doc’s committed heads.

pub fn len(&self) -> usize

How many changes the index holds.

pub fn is_empty(&self) -> bool

Whether the index holds no change.

pub fn hash(&self, position: usize) -> Option<ChangeHash>

The hash of the change at position in causal order.

pub fn full(&self, doc: &AutoCommit, position: usize) -> Option<Version>

The change at position with everything its entry records, read again from doc.

pub fn brought_back( &mut self, doc: &AutoCommit, version: &Version, ) -> Vec<String>

What the redo change version brought back, by full hash; empty for any other change (brought_back, kept per change).

pub fn position(&self, hash: &ChangeHash) -> Option<usize>

Where a change sits in causal order.

pub fn steps( &mut self, doc: &AutoCommit, owns: &dyn Fn(&Version) -> bool, step_of: &dyn Fn(&Version) -> Option<String>, limit: usize, ) -> Vec<Vec<Version>>

The steps in effect that owns claims, newest first, at most limit: each step the consecutive changes step_of puts together (one gesture), newest first. A step undone, or superseded by a redo that stands for it, is not in effect. What one engine undoes, whoever asks (Ctrl+Z, an agent’s or a script’s undo).

pub fn undos( &mut self, doc: &AutoCommit, owns: &dyn Fn(&Version) -> bool, limit: usize, ) -> Vec<Version>

The undos in effect that owns claims, newest first, at most limit: what redo brings back. A newer step of the same owner ends them.

Trait Implementations

impl Default for StepIndex

fn default() -> StepIndex

Returns the “default value” for a type.