automerge/rust/automerge/src/query/list_vals.rs

36 lines
917 B
Rust

use crate::op_tree::OpTreeNode;
use crate::query::{QueryResult, TreeQuery};
use crate::types::{ElemId, Op};
use std::fmt::Debug;
#[derive(Debug, Clone, PartialEq)]
pub(crate) struct ListVals {
last_elem: Option<ElemId>,
pub(crate) ops: Vec<Op>,
}
impl ListVals {
pub(crate) fn new() -> Self {
ListVals {
last_elem: None,
ops: vec![],
}
}
}
impl<'a> TreeQuery<'a> for ListVals {
fn query_node(&mut self, child: &OpTreeNode, ops: &[Op]) -> QueryResult {
let start = 0;
for pos in start..child.len() {
let op = &ops[child.get(pos).unwrap()];
if op.insert {
self.last_elem = None;
}
if self.last_elem.is_none() && op.visible() {
self.last_elem = op.elemid();
self.ops.push(op.clone());
}
}
QueryResult::Finish
}
}