Struct undo::Checkpoint

pub struct Checkpoint<'a, T, R> { /* fields omitted */ }

A checkpoint wrapper.

Wraps a record or history and gives it checkpoint functionality. This allows the record or history to cancel all changes made since creating the checkpoint.

Examples

let mut record = Record::default();
let mut cp = record.checkpoint();
cp.apply(Add('a'))?;
cp.apply(Add('b'))?;
cp.apply(Add('c'))?;
assert_eq!(cp.as_receiver(), "abc");
cp.cancel()?;
assert_eq!(record.as_receiver(), "");

Methods

impl<'a, T, R> Checkpoint<'a, T, R>

pub fn new(inner: &'a mut T) -> Checkpoint<'a, T, R>

Returns a checkpoint.

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more commands in the checkpoint.

Panics

Panics if the new capacity overflows usize.

pub fn capacity(&self) -> usize

Returns the capacity of the checkpoint.

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the checkpoint as much as possible.

pub fn len(&self) -> usize

Returns the number of commands in the checkpoint.

pub fn is_empty(&self) -> bool

Returns true if the checkpoint is empty.

pub fn commit(self)

Commits the changes and consumes the checkpoint.

impl<'_, R> Checkpoint<'_, Record<R>, R>

pub fn apply(&mut self, command: impl Command<R> + 'static) -> Result where
    R: 'static, 

Calls the apply method.

pub fn undo(&mut self) -> Option<Result>

Calls the undo method.

pub fn redo(&mut self) -> Option<Result>

Calls the redo method.

pub fn go_to(&mut self, current: usize) -> Option<Result>

Calls the go_to method.

pub fn extend<C: Command<R> + 'static>(
    &mut self,
    commands: impl IntoIterator<Item = C>
) -> Result where
    R: 'static, 

Calls the extend method.

pub fn cancel(self) -> Result

Cancels the changes and consumes the checkpoint.

Errors

If an error occur when canceling the changes, the error is returned and the remaining commands are not canceled.

pub fn checkpoint(&mut self) -> Checkpoint<Record<R>, R>

Returns a checkpoint.

pub fn queue(&mut self) -> Queue<Record<R>, R>

Returns a queue.

pub fn as_receiver(&self) -> &R

Returns a reference to the receiver.

pub fn as_mut_receiver(&mut self) -> &mut R

Returns a mutable reference to the receiver.

This method should only be used when doing changes that should not be able to be undone.

impl<'_, R> Checkpoint<'_, History<R>, R>

pub fn apply(&mut self, command: impl Command<R> + 'static) -> Result where
    R: 'static, 

Calls the apply method.

pub fn undo(&mut self) -> Option<Result>

Calls the undo method.

pub fn redo(&mut self) -> Option<Result>

Calls the redo method.

pub fn go_to(&mut self, branch: usize, current: usize) -> Option<Result> where
    R: 'static, 

Calls the go_to method.

pub fn extend<C: Command<R> + 'static>(
    &mut self,
    commands: impl IntoIterator<Item = C>
) -> Result where
    R: 'static, 

Calls the extend method.

pub fn cancel(self) -> Result where
    R: 'static, 

Cancels the changes and consumes the checkpoint.

Errors

If an error occur when canceling the changes, the error is returned and the remaining commands are not canceled.

pub fn checkpoint(&mut self) -> Checkpoint<History<R>, R>

Returns a checkpoint.

pub fn queue(&mut self) -> Queue<History<R>, R>

Returns a queue.

pub fn as_receiver(&self) -> &R

Returns a reference to the receiver.

pub fn as_mut_receiver(&mut self) -> &mut R

Returns a mutable reference to the receiver.

This method should only be used when doing changes that should not be able to be undone.

Trait Implementations

impl<'_, R> AsRef<R> for Checkpoint<'_, Record<R>, R>

fn as_ref(&self) -> &R

Performs the conversion.

impl<'_, R> AsRef<R> for Checkpoint<'_, History<R>, R>

fn as_ref(&self) -> &R

Performs the conversion.

impl<'_, R> AsMut<R> for Checkpoint<'_, Record<R>, R>

fn as_mut(&mut self) -> &mut R

Performs the conversion.

impl<'_, R> AsMut<R> for Checkpoint<'_, History<R>, R>

fn as_mut(&mut self) -> &mut R

Performs the conversion.

impl<'a, T, R> From<&'a mut T> for Checkpoint<'a, T, R>

fn from(inner: &'a mut T) -> Self

Performs the conversion.

impl<'a, T: Debug, R: Debug> Debug for Checkpoint<'a, T, R>

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

Formats the value using the given formatter.