Function find_target_vertex

atomic-core/src/apply/edge.rs:296–307

Find the target span for an edge operation. Given a position, finds the span that contains it. For edge targets, we want the span starting at or containing the position. # Arguments `txn` - Transaction for graph lookups `pos` - Position to find # Returns The span containing the position. # Errors Returns `BlockNotFound` if no span contains this position.

(
    txn: &T,
    pos: Position<NodeId>,
)

///
/// Returns `BlockNotFound` if no span contains this position.
pub fn find_target_vertex<T: GraphTxnT>(
    txn: &T,
    pos: Position<NodeId>,
) -> Result<GraphNode<NodeId>, LocalApplyError> {
    if pos.change.is_root() {
        // ROOT span is empty at position 0
        return Ok(GraphNode::root());
    }

    txn.find_block(pos)
        .map_err(|_| LocalApplyError::BlockNotFound { position: pos })
}

// Deletion Handling