Function undo::from_fn

pub fn from_fn<T, F>(f: F) -> FromFn<T, F>

Creates a command from the provided function.

The undo functionality is provided by cloning the original data before editing it.

Examples

let mut record = Record::default();
record.apply(from_fn(|s: &mut String| s.push('a')))?;
record.apply(from_fn(|s: &mut String| s.push('b')))?;
record.apply(from_fn(|s: &mut String| s.push('c')))?;
assert_eq!(record.target(), "abc");
record.undo()?;
record.undo()?;
record.undo()?;
assert_eq!(record.target(), "");
record.redo()?;
record.redo()?;
record.redo()?;
assert_eq!(record.target(), "abc");