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use crate::{Edge, EdgeID, EdgeInsertID, EdgeQuery, GraphKind, NodeID};
pub mod weighted;
use crate::{edges::typed_edges::IndeterminateEdge, errors::GraphError, vertexes::NodeDegree};
use std::{
mem::size_of,
ops::{Deref, DerefMut},
};
pub mod named;
/// Represent a graph storage, with a set of nodes and edges.
///
/// # Examples
///
/// ```
/// use graph_theory::GraphEngine;
/// ```
#[allow(unused_variables)]
pub trait GraphEngine<'a>
where
Self: Sized,
{
/// According to a given vertex, find all neighbor nodes
type NeighborIterator: DoubleEndedIterator<Item = NodeID>;
/// An iterator over the edges.
type BridgeIterator: DoubleEndedIterator<Item = IndeterminateEdge>;
/// An iterator over the nodes.
type NodeTraverser: DoubleEndedIterator<Item = NodeID>;
/// An iterator over the edges.
type EdgeTraverser: DoubleEndedIterator<Item = EdgeID>;
/// An iterator over the edges.
type BridgeTraverser: DoubleEndedIterator<Item = IndeterminateEdge>;
/// Check the graph kind, it can be directed or undirected.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).get_node(5), true);
/// assert_eq!(CompleteGraph::one_way(5).get_node(6), false);
/// ```
fn graph_kind(&self) -> GraphKind;
/// Check if the node exists, return the node id if exists.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).get_node(5), true);
/// assert_eq!(CompleteGraph::one_way(5).get_node(6), false);
/// ```
fn get_node(&self, node: NodeID) -> Result<NodeID, GraphError>;
/// Traverse all nodes in the graph.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// let mut graph = CompleteGraph::one_way(5);
/// assert_eq!(graph.all_nodes().count(), 20)
/// ```
fn all_nodes(&'a self) -> Self::NodeTraverser;
/// Count the number of nodes in the graph.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).count_nodes(), 5);
/// ```
fn count_nodes(&'a self) -> usize {
self.all_nodes().count()
}
/// Check if the node exists, return the node id if exists.
///
/// Return [None] if the node does not exist.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).count_nodes(), 5);
/// ```
fn all_neighbors(&'a self, node: NodeID) -> Self::NeighborIterator;
/// Find all vertices ending at a given point
///
/// Return [None] if the node does not exist.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).count_nodes(), 5);
/// ```
fn get_outgoing(&'a self, node: NodeID) -> Self::NeighborIterator {
debug_assert!(self.graph_kind() == GraphKind::Undirected);
self.all_neighbors(node)
}
/// Check if the node exists, return the node id if exists.
///
/// Return [None] if the node does not exist.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).count_nodes(), 5);
/// ```
fn get_incoming(&'a self, node: NodeID) -> Self::NeighborIterator {
debug_assert!(self.graph_kind() == GraphKind::Undirected);
self.all_neighbors(node)
}
/// Check if the node exists, return the node id if exists.
///
/// Return [None] if the node does not exist.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).count_nodes(), 5);
/// ```
fn count_degree(&'a self, node: NodeID) -> NodeDegree {
match self.graph_kind() {
GraphKind::Directed => {
NodeDegree::Directed { in_coming: self.get_incoming(node).count(), out_going: self.get_outgoing(node).count() }
}
GraphKind::Undirected => NodeDegree::Undirected { total: self.all_neighbors(node).count() },
}
}
/// Check if the edge exists, return the node id if exists.
///
/// At most one element will be returned, even if there are multiple edges with the same starting point and ending point.
///
/// If you need to return all eligible edges, use [Self::get_bridges].
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).get_node(5), true);
/// assert_eq!(CompleteGraph::one_way(5).get_node(6), false);
/// ```
fn get_edge(&self, edge: EdgeID) -> Result<EdgeID, GraphError>;
/// Get the edges of the graph.
///
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// let mut graph = CompleteGraph::one_way(5);
/// assert_eq!(graph.all_nodes().count(), 20)
/// ```
fn all_edges(&'a self) -> Self::EdgeTraverser;
/// Count the number of edges in the graph.
///
/// # Examples
///
/// ```
/// # use graph_theory::{GraphEngine};
/// # use graph_theory::graph_engines::{CycleGraph, StarGraph, CompleteGraph};
/// assert_eq!(CycleGraph::one_way(5).count_edges(), 5);
/// assert_eq!(CycleGraph::two_way(5).count_edges(), 10);
/// assert_eq!(StarGraph::one_way(5).count_edges(), 5);
/// assert_eq!(StarGraph::two_way(5).count_edges(), 10);
/// assert_eq!(CompleteGraph::one_way(5).count_edges(), 5);
/// assert_eq!(CompleteGraph::one_way(5).count_edges(), 10);
/// ```
fn count_edges(&'a self) -> usize {
self.all_edges().count()
}
fn get_bridge(&self, edge: EdgeID) -> Result<IndeterminateEdge, GraphError>;
/// Give all edges matching the start and end points
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// assert_eq!(CompleteGraph::one_way(5).get_node(5), true);
/// assert_eq!(CompleteGraph::one_way(5).get_node(6), false);
/// ```
fn get_bridges(&'a self, from: NodeID, goto: NodeID) -> Self::BridgeIterator;
/// Get the edges of the graph.
///
///
/// ```
/// use graph_theory::{graph_engines::CompleteGraph, GraphEngine};
/// let mut graph = CompleteGraph::one_way(5);
/// assert_eq!(graph.all_nodes().count(), 20)
/// ```
fn all_bridges(&'a self) -> Self::BridgeTraverser;
/// Query the total space occupied by the structure, return 0 if failed to query
///
/// Note that this volume contains garbage data, call [GraphEngine::shrink] at the right time to perform garbage collection.
fn size_hint(&self) -> usize {
size_of::<Self>()
}
}
/// Mark a graph engine that can add and delete edges or points
pub trait MutableGraph: for<'a> GraphEngine<'a> {
/// Insert a node without any neighbors (edges).
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::AdjacencyNodeList, GraphEngine};
/// let mut graph = AdjacencyNodeList::default();
/// assert_eq!(graph.count_nodes(), 0);
/// graph.insert_node(5);
/// assert_eq!(graph.count_nodes(), 1);
/// ```
fn insert_node(&mut self, node_id: usize) -> bool;
/// Insert a node without any neighbors (edges).
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::AdjacencyNodeList, GraphEngine};
/// let mut graph = AdjacencyNodeList::default();
/// assert_eq!(graph.count_nodes(), 0);
/// graph.insert_node(5);
/// assert_eq!(graph.count_nodes(), 1);
/// ```
fn create_node(&mut self) -> usize;
/// Remove the given node.
///
/// # Undefined Behavior
///
/// - If the node has any edges, the behavior is undefined.
///
/// It is recommended to remove all edges before removing the node, see [`GraphEngine::remove_node_with_edges`].
///
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::AdjacencyNodeList, GraphEngine};
/// let mut graph = AdjacencyNodeList::default();
/// assert_eq!(graph.count_nodes(), 0);
/// graph.insert_node(5);
/// assert_eq!(graph.count_nodes(), 1);
/// ```
fn remove_node(&mut self, node_id: usize) {
self.remove_node_with_edges(node_id)
}
/// Remove the given node and all edges connected to it.
///
/// # Examples
///
/// ```
/// use graph_theory::{graph_engines::AdjacencyNodeList, GraphEngine};
/// let mut graph = AdjacencyNodeList::default();
/// assert_eq!(graph.count_nodes(), 0);
/// graph.insert_node(5);
/// assert_eq!(graph.count_nodes(), 1);
/// ```
fn remove_node_with_edges(&mut self, node_id: usize);
/// Insert a edge between two nodes.
///
/// # Undefined Behaviors
///
/// - If the nodes does not exist, the behavior is undefined.
///
/// It is recommended to check the existence of the nodes before inserting the edge, see [`GraphEngine::insert_edge_with_nodes`].
///
/// - Insert undirected edge to directed graph.
///
/// Two edges will be inserted, but only return last edge's id.
///
/// # Panics
///
/// - No such ability
///
/// Not all graph engine supports insert edge.
///
/// - Insert disconnected edge
///
/// Meaningless, don't do that.
///
/// # Examples
///
/// ```
/// use graph_theory::GraphEngine;
/// ```
fn insert_edge<E: Edge>(&mut self, edge: E) -> EdgeInsertID {
self.insert_edge_with_nodes(edge)
}
/// Insert edge to graph, if the nodes does not exist, also insert them.
///
/// # Panics
///
/// - No such ability
///
/// Not all graph engine supports insert edge.
///
/// # Examples
///
/// ```
/// use graph_theory::GraphEngine;
/// ```
fn insert_edge_with_nodes<E: Edge>(&mut self, edge: E) -> EdgeInsertID;
/// Remove edge by given edge-id or start and end node-id.
///
/// # Panics
///
/// - No such ability
///
/// Not all graph engine supports insert edge.
///
/// # Examples
///
/// ```
/// use graph_theory::GraphEngine;
/// ```
fn remove_edge<E>(&mut self, edge: E)
where
E: Into<EdgeQuery>;
/// Remove invalid edges and nodes to improve the efficiency of subsequent queries.
fn shrink(&mut self) {}
}