Trait undo::Action

pub trait Action {
    type Target;
    type Output;
    type Error;
    fn apply(&mut self, target: &mut Self::Target) -> Result<Self>;
    fn undo(&mut self, target: &mut Self::Target) -> Result<Self>;

    fn redo(&mut self, target: &mut Self::Target) -> Result<Self> { ... }
    fn merge(&mut self, _: &mut Self) -> Merged
    where
        Self: Sized,
    { ... }
}

Base functionality for all actions.

Associated Types

type Target

The target type.

type Output

The output type.

type Error

The error type.

Required methods

fn apply(&mut self, target: &mut Self::Target) -> Result<Self>

Applies the action on the target and returns Ok if everything went fine, and Err if something went wrong.

fn undo(&mut self, target: &mut Self::Target) -> Result<Self>

Restores the state of the target as it was before the action was applied and returns Ok if everything went fine, and Err if something went wrong.

Provided methods

fn redo(&mut self, target: &mut Self::Target) -> Result<Self>

Reapplies the action on the target and return Ok if everything went fine, and Err if something went wrong.

The default implementation uses the apply implementation.

fn merge(&mut self, _: &mut Self) -> Merged where
    Self: Sized, 

Used for manual merging of actions.

Implementors