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use serde::{Deserialize, Serialize};
use crate::crdt::crdt::*;
/// Deletable object (once deleted, cannot go back)
#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub enum Deletable<T> {
Present(T),
Deleted,
}
impl<T: Crdt> Deletable<T> {
/// Create a new deletable object that isn't deleted
pub fn present(v: T) -> Self {
Self::Present(v)
}
/// Create a new deletable object that is deleted
pub fn delete() -> Self {
Self::Deleted
}
/// As option
pub fn as_option(&self) -> Option<&T> {
match self {
Self::Present(v) => Some(v),
Self::Deleted => None,
}
}
/// As option, mutable
pub fn as_option_mut(&mut self) -> Option<&mut T> {
match self {
Self::Present(v) => Some(v),
Self::Deleted => None,
}
}
/// Into option
pub fn into_option(self) -> Option<T> {
match self {
Self::Present(v) => Some(v),
Self::Deleted => None,
}
}
/// Is object deleted?
pub fn is_deleted(&self) -> bool {
matches!(self, Self::Deleted)
}
}
impl<T> From<Option<T>> for Deletable<T> {
fn from(v: Option<T>) -> Self {
v.map(Self::Present).unwrap_or(Self::Deleted)
}
}
impl<T> From<Deletable<T>> for Option<T> {
fn from(v: Deletable<T>) -> Option<T> {
match v {
Deletable::Present(v) => Some(v),
Deletable::Deleted => None,
}
}
}
impl<T: Crdt> Crdt for Deletable<T> {
fn merge(&mut self, other: &Self) {
if let Deletable::Present(v) = self {
match other {
Deletable::Deleted => *self = Deletable::Deleted,
Deletable::Present(v2) => v.merge(v2),
}
}
}
}
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