blob: 3d047424a9b3f257d4a7140ac4df9d112cd13c80 [file] [log] [blame]
//! `GraphMap<N, E, Ty>` is a graph datastructure where node values are mapping
//! keys.
use indexmap::map::Keys;
use indexmap::map::{Iter as IndexMapIter, IterMut as IndexMapIterMut};
use indexmap::IndexMap;
use std::cmp::Ordering;
use std::collections::HashSet;
use std::fmt;
use std::hash::{self, Hash};
use std::iter::FromIterator;
use std::iter::{Cloned, DoubleEndedIterator};
use std::marker::PhantomData;
use std::mem;
use std::ops::{Deref, Index, IndexMut};
use std::slice::Iter;
use crate::{Directed, Direction, EdgeType, Incoming, Outgoing, Undirected};
use crate::graph::node_index;
use crate::graph::Graph;
use crate::visit;
use crate::IntoWeightedEdge;
/// A `GraphMap` with undirected edges.
///
/// For example, an edge between *1* and *2* is equivalent to an edge between
/// *2* and *1*.
pub type UnGraphMap<N, E> = GraphMap<N, E, Undirected>;
/// A `GraphMap` with directed edges.
///
/// For example, an edge from *1* to *2* is distinct from an edge from *2* to
/// *1*.
pub type DiGraphMap<N, E> = GraphMap<N, E, Directed>;
/// `GraphMap<N, E, Ty>` is a graph datastructure using an associative array
/// of its node weights `N`.
///
/// It uses an combined adjacency list and sparse adjacency matrix
/// representation, using **O(|V| + |E|)** space, and allows testing for edge
/// existence in constant time.
///
/// `GraphMap` is parameterized over:
///
/// - Associated data `N` for nodes and `E` for edges, called *weights*.
/// - The node weight `N` must implement `Copy` and will be used as node
/// identifier, duplicated into several places in the data structure.
/// It must be suitable as a hash table key (implementing `Eq + Hash`).
/// The node type must also implement `Ord` so that the implementation can
/// order the pair (`a`, `b`) for an edge connecting any two nodes `a` and `b`.
/// - `E` can be of arbitrary type.
/// - Edge type `Ty` that determines whether the graph edges are directed or
/// undirected.
///
/// You can use the type aliases `UnGraphMap` and `DiGraphMap` for convenience.
///
/// `GraphMap` does not allow parallel edges, but self loops are allowed.
///
/// Depends on crate feature `graphmap` (default).
#[derive(Clone)]
pub struct GraphMap<N, E, Ty> {
nodes: IndexMap<N, Vec<(N, CompactDirection)>>,
edges: IndexMap<(N, N), E>,
ty: PhantomData<Ty>,
}
impl<N: Eq + Hash + fmt::Debug, E: fmt::Debug, Ty: EdgeType> fmt::Debug for GraphMap<N, E, Ty> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.nodes.fmt(f)
}
}
/// A trait group for `GraphMap`'s node identifier.
pub trait NodeTrait: Copy + Ord + Hash {}
impl<N> NodeTrait for N where N: Copy + Ord + Hash {}
// non-repr(usize) version of Direction
#[derive(Copy, Clone, Debug, PartialEq)]
enum CompactDirection {
Outgoing,
Incoming,
}
impl CompactDirection {
/// Return the opposite `CompactDirection`.
#[inline]
pub fn opposite(self) -> CompactDirection {
match self {
CompactDirection::Outgoing => CompactDirection::Incoming,
CompactDirection::Incoming => CompactDirection::Outgoing,
}
}
}
impl From<Direction> for CompactDirection {
fn from(d: Direction) -> Self {
match d {
Outgoing => CompactDirection::Outgoing,
Incoming => CompactDirection::Incoming,
}
}
}
impl From<CompactDirection> for Direction {
fn from(d: CompactDirection) -> Self {
match d {
CompactDirection::Outgoing => Outgoing,
CompactDirection::Incoming => Incoming,
}
}
}
impl PartialEq<Direction> for CompactDirection {
fn eq(&self, rhs: &Direction) -> bool {
(*self as usize) == (*rhs as usize)
}
}
impl<N, E, Ty> GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
/// Create a new `GraphMap`
pub fn new() -> Self {
Self::default()
}
/// Create a new `GraphMap` with estimated capacity.
pub fn with_capacity(nodes: usize, edges: usize) -> Self {
GraphMap {
nodes: IndexMap::with_capacity(nodes),
edges: IndexMap::with_capacity(edges),
ty: PhantomData,
}
}
/// Return the current node and edge capacity of the graph.
pub fn capacity(&self) -> (usize, usize) {
(self.nodes.capacity(), self.edges.capacity())
}
/// Use their natural order to map the node pair (a, b) to a canonical edge id.
#[inline]
fn edge_key(a: N, b: N) -> (N, N) {
if Ty::is_directed() || a <= b {
(a, b)
} else {
(b, a)
}
}
/// Whether the graph has directed edges.
pub fn is_directed(&self) -> bool {
Ty::is_directed()
}
/// Create a new `GraphMap` from an iterable of edges.
///
/// Node values are taken directly from the list.
/// Edge weights `E` may either be specified in the list,
/// or they are filled with default values.
///
/// Nodes are inserted automatically to match the edges.
///
/// ```
/// use petgraph::graphmap::UnGraphMap;
///
/// // Create a new undirected GraphMap.
/// // Use a type hint to have `()` be the edge weight type.
/// let gr = UnGraphMap::<_, ()>::from_edges(&[
/// (0, 1), (0, 2), (0, 3),
/// (1, 2), (1, 3),
/// (2, 3),
/// ]);
/// ```
pub fn from_edges<I>(iterable: I) -> Self
where
I: IntoIterator,
I::Item: IntoWeightedEdge<E, NodeId = N>,
{
Self::from_iter(iterable)
}
/// Return the number of nodes in the graph.
pub fn node_count(&self) -> usize {
self.nodes.len()
}
/// Return the number of edges in the graph.
pub fn edge_count(&self) -> usize {
self.edges.len()
}
/// Remove all nodes and edges
pub fn clear(&mut self) {
self.nodes.clear();
self.edges.clear();
}
/// Add node `n` to the graph.
pub fn add_node(&mut self, n: N) -> N {
self.nodes.entry(n).or_insert(Vec::new());
n
}
/// Return `true` if node `n` was removed.
///
/// Computes in **O(V)** time, due to the removal of edges with other nodes.
pub fn remove_node(&mut self, n: N) -> bool {
let links = match self.nodes.swap_remove(&n) {
None => return false,
Some(sus) => sus,
};
for (succ, dir) in links {
let edge = if dir == CompactDirection::Outgoing {
Self::edge_key(n, succ)
} else {
Self::edge_key(succ, n)
};
// remove all successor links
self.remove_single_edge(&succ, &n, dir.opposite());
// Remove all edge values
self.edges.swap_remove(&edge);
}
true
}
/// Return `true` if the node is contained in the graph.
pub fn contains_node(&self, n: N) -> bool {
self.nodes.contains_key(&n)
}
/// Add an edge connecting `a` and `b` to the graph, with associated
/// data `weight`. For a directed graph, the edge is directed from `a`
/// to `b`.
///
/// Inserts nodes `a` and/or `b` if they aren't already part of the graph.
///
/// Return `None` if the edge did not previously exist, otherwise,
/// the associated data is updated and the old value is returned
/// as `Some(old_weight)`.
///
/// ```
/// // Create a GraphMap with directed edges, and add one edge to it
/// use petgraph::graphmap::DiGraphMap;
///
/// let mut g = DiGraphMap::new();
/// g.add_edge("x", "y", -1);
/// assert_eq!(g.node_count(), 2);
/// assert_eq!(g.edge_count(), 1);
/// assert!(g.contains_edge("x", "y"));
/// assert!(!g.contains_edge("y", "x"));
/// ```
pub fn add_edge(&mut self, a: N, b: N, weight: E) -> Option<E> {
if let old @ Some(_) = self.edges.insert(Self::edge_key(a, b), weight) {
old
} else {
// insert in the adjacency list if it's a new edge
self.nodes
.entry(a)
.or_insert_with(|| Vec::with_capacity(1))
.push((b, CompactDirection::Outgoing));
if a != b {
// self loops don't have the Incoming entry
self.nodes
.entry(b)
.or_insert_with(|| Vec::with_capacity(1))
.push((a, CompactDirection::Incoming));
}
None
}
}
/// Remove edge relation from a to b
///
/// Return `true` if it did exist.
fn remove_single_edge(&mut self, a: &N, b: &N, dir: CompactDirection) -> bool {
match self.nodes.get_mut(a) {
None => false,
Some(sus) => {
if Ty::is_directed() {
match sus.iter().position(|elt| elt == &(*b, dir)) {
Some(index) => {
sus.swap_remove(index);
true
}
None => false,
}
} else {
match sus.iter().position(|elt| &elt.0 == b) {
Some(index) => {
sus.swap_remove(index);
true
}
None => false,
}
}
}
}
}
/// Remove edge from `a` to `b` from the graph and return the edge weight.
///
/// Return `None` if the edge didn't exist.
///
/// ```
/// // Create a GraphMap with undirected edges, and add and remove an edge.
/// use petgraph::graphmap::UnGraphMap;
///
/// let mut g = UnGraphMap::new();
/// g.add_edge("x", "y", -1);
///
/// let edge_data = g.remove_edge("y", "x");
/// assert_eq!(edge_data, Some(-1));
/// assert_eq!(g.edge_count(), 0);
/// ```
pub fn remove_edge(&mut self, a: N, b: N) -> Option<E> {
let exist1 = self.remove_single_edge(&a, &b, CompactDirection::Outgoing);
let exist2 = if a != b {
self.remove_single_edge(&b, &a, CompactDirection::Incoming)
} else {
exist1
};
let weight = self.edges.remove(&Self::edge_key(a, b));
debug_assert!(exist1 == exist2 && exist1 == weight.is_some());
weight
}
/// Return `true` if the edge connecting `a` with `b` is contained in the graph.
pub fn contains_edge(&self, a: N, b: N) -> bool {
self.edges.contains_key(&Self::edge_key(a, b))
}
/// Return an iterator over the nodes of the graph.
///
/// Iterator element type is `N`.
pub fn nodes(&self) -> Nodes<N> {
Nodes {
iter: self.nodes.keys().cloned(),
}
}
/// Return an iterator of all nodes with an edge starting from `a`.
///
/// - `Directed`: Outgoing edges from `a`.
/// - `Undirected`: All edges from or to `a`.
///
/// Produces an empty iterator if the node doesn't exist.<br>
/// Iterator element type is `N`.
pub fn neighbors(&self, a: N) -> Neighbors<N, Ty> {
Neighbors {
iter: match self.nodes.get(&a) {
Some(neigh) => neigh.iter(),
None => [].iter(),
},
ty: self.ty,
}
}
/// Return an iterator of all neighbors that have an edge between them and
/// `a`, in the specified direction.
/// If the graph's edges are undirected, this is equivalent to *.neighbors(a)*.
///
/// - `Directed`, `Outgoing`: All edges from `a`.
/// - `Directed`, `Incoming`: All edges to `a`.
/// - `Undirected`: All edges from or to `a`.
///
/// Produces an empty iterator if the node doesn't exist.<br>
/// Iterator element type is `N`.
pub fn neighbors_directed(&self, a: N, dir: Direction) -> NeighborsDirected<N, Ty> {
NeighborsDirected {
iter: match self.nodes.get(&a) {
Some(neigh) => neigh.iter(),
None => [].iter(),
},
start_node: a,
dir,
ty: self.ty,
}
}
/// Return an iterator of target nodes with an edge starting from `a`,
/// paired with their respective edge weights.
///
/// - `Directed`: Outgoing edges from `a`.
/// - `Undirected`: All edges from or to `a`.
///
/// Produces an empty iterator if the node doesn't exist.<br>
/// Iterator element type is `(N, &E)`.
pub fn edges(&self, from: N) -> Edges<N, E, Ty> {
Edges {
from,
iter: self.neighbors(from),
edges: &self.edges,
}
}
/// Return an iterator of target nodes with an edge starting from `a`,
/// paired with their respective edge weights.
///
/// - `Directed`, `Outgoing`: All edges from `a`.
/// - `Directed`, `Incoming`: All edges to `a`.
/// - `Undirected`, `Outgoing`: All edges connected to `a`, with `a` being the source of each
/// edge.
/// - `Undirected`, `Incoming`: All edges connected to `a`, with `a` being the target of each
/// edge.
///
/// Produces an empty iterator if the node doesn't exist.<br>
/// Iterator element type is `(N, &E)`.
pub fn edges_directed(&self, from: N, dir: Direction) -> EdgesDirected<N, E, Ty> {
EdgesDirected {
from,
iter: self.neighbors_directed(from, dir),
dir,
edges: &self.edges,
}
}
/// Return a reference to the edge weight connecting `a` with `b`, or
/// `None` if the edge does not exist in the graph.
pub fn edge_weight(&self, a: N, b: N) -> Option<&E> {
self.edges.get(&Self::edge_key(a, b))
}
/// Return a mutable reference to the edge weight connecting `a` with `b`, or
/// `None` if the edge does not exist in the graph.
pub fn edge_weight_mut(&mut self, a: N, b: N) -> Option<&mut E> {
self.edges.get_mut(&Self::edge_key(a, b))
}
/// Return an iterator over all edges of the graph with their weight in arbitrary order.
///
/// Iterator element type is `(N, N, &E)`
pub fn all_edges(&self) -> AllEdges<N, E, Ty> {
AllEdges {
inner: self.edges.iter(),
ty: self.ty,
}
}
/// Return an iterator over all edges of the graph in arbitrary order, with a mutable reference
/// to their weight.
///
/// Iterator element type is `(N, N, &mut E)`
pub fn all_edges_mut(&mut self) -> AllEdgesMut<N, E, Ty> {
AllEdgesMut {
inner: self.edges.iter_mut(),
ty: self.ty,
}
}
/// Return a `Graph` that corresponds to this `GraphMap`.
///
/// 1. Note that node and edge indices in the `Graph` have nothing in common
/// with the `GraphMap`s node weights `N`. The node weights `N` are used as
/// node weights in the resulting `Graph`, too.
/// 2. Note that the index type is user-chosen.
///
/// Computes in **O(|V| + |E|)** time (average).
///
/// **Panics** if the number of nodes or edges does not fit with
/// the resulting graph's index type.
pub fn into_graph<Ix>(self) -> Graph<N, E, Ty, Ix>
where
Ix: crate::graph::IndexType,
{
// assuming two successive iterations of the same hashmap produce the same order
let mut gr = Graph::with_capacity(self.node_count(), self.edge_count());
for (&node, _) in &self.nodes {
gr.add_node(node);
}
for ((a, b), edge_weight) in self.edges {
let (ai, _, _) = self.nodes.get_full(&a).unwrap();
let (bi, _, _) = self.nodes.get_full(&b).unwrap();
gr.add_edge(node_index(ai), node_index(bi), edge_weight);
}
gr
}
}
/// Create a new `GraphMap` from an iterable of edges.
impl<N, E, Ty, Item> FromIterator<Item> for GraphMap<N, E, Ty>
where
Item: IntoWeightedEdge<E, NodeId = N>,
N: NodeTrait,
Ty: EdgeType,
{
fn from_iter<I>(iterable: I) -> Self
where
I: IntoIterator<Item = Item>,
{
let iter = iterable.into_iter();
let (low, _) = iter.size_hint();
let mut g = Self::with_capacity(0, low);
g.extend(iter);
g
}
}
/// Extend the graph from an iterable of edges.
///
/// Nodes are inserted automatically to match the edges.
impl<N, E, Ty, Item> Extend<Item> for GraphMap<N, E, Ty>
where
Item: IntoWeightedEdge<E, NodeId = N>,
N: NodeTrait,
Ty: EdgeType,
{
fn extend<I>(&mut self, iterable: I)
where
I: IntoIterator<Item = Item>,
{
let iter = iterable.into_iter();
let (low, _) = iter.size_hint();
self.edges.reserve(low);
for elt in iter {
let (source, target, weight) = elt.into_weighted_edge();
self.add_edge(source, target, weight);
}
}
}
iterator_wrap! {
impl (Iterator DoubleEndedIterator ExactSizeIterator) for
#[derive(Debug, Clone)]
struct Nodes <'a, N> where { N: 'a + NodeTrait }
item: N,
iter: Cloned<Keys<'a, N, Vec<(N, CompactDirection)>>>,
}
#[derive(Debug, Clone)]
pub struct Neighbors<'a, N, Ty = Undirected>
where
N: 'a,
Ty: EdgeType,
{
iter: Iter<'a, (N, CompactDirection)>,
ty: PhantomData<Ty>,
}
impl<'a, N, Ty> Iterator for Neighbors<'a, N, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type Item = N;
fn next(&mut self) -> Option<N> {
if Ty::is_directed() {
(&mut self.iter)
.filter_map(|&(n, dir)| if dir == Outgoing { Some(n) } else { None })
.next()
} else {
self.iter.next().map(|&(n, _)| n)
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let (lower, upper) = self.iter.size_hint();
if Ty::is_directed() {
(0, upper)
} else {
(lower, upper)
}
}
}
#[derive(Debug, Clone)]
pub struct NeighborsDirected<'a, N, Ty>
where
N: 'a,
Ty: EdgeType,
{
iter: Iter<'a, (N, CompactDirection)>,
start_node: N,
dir: Direction,
ty: PhantomData<Ty>,
}
impl<'a, N, Ty> Iterator for NeighborsDirected<'a, N, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type Item = N;
fn next(&mut self) -> Option<N> {
if Ty::is_directed() {
let self_dir = self.dir;
let start_node = self.start_node;
(&mut self.iter)
.filter_map(move |&(n, dir)| {
if dir == self_dir || n == start_node {
Some(n)
} else {
None
}
})
.next()
} else {
self.iter.next().map(|&(n, _)| n)
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let (lower, upper) = self.iter.size_hint();
if Ty::is_directed() {
(0, upper)
} else {
(lower, upper)
}
}
}
#[derive(Debug, Clone)]
pub struct Edges<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
Ty: EdgeType,
{
from: N,
edges: &'a IndexMap<(N, N), E>,
iter: Neighbors<'a, N, Ty>,
}
impl<'a, N, E, Ty> Iterator for Edges<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = (N, N, &'a E);
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|b| {
let a = self.from;
match self.edges.get(&GraphMap::<N, E, Ty>::edge_key(a, b)) {
None => unreachable!(),
Some(edge) => (a, b, edge),
}
})
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
#[derive(Debug, Clone)]
pub struct EdgesDirected<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
Ty: EdgeType,
{
from: N,
dir: Direction,
edges: &'a IndexMap<(N, N), E>,
iter: NeighborsDirected<'a, N, Ty>,
}
impl<'a, N, E, Ty> Iterator for EdgesDirected<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = (N, N, &'a E);
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|mut b| {
let mut a = self.from;
if self.dir == Direction::Incoming {
mem::swap(&mut a, &mut b);
}
match self.edges.get(&GraphMap::<N, E, Ty>::edge_key(a, b)) {
None => unreachable!(),
Some(edge) => (a, b, edge),
}
})
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
#[derive(Debug, Clone)]
pub struct AllEdges<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
{
inner: IndexMapIter<'a, (N, N), E>,
ty: PhantomData<Ty>,
}
impl<'a, N, E, Ty> Iterator for AllEdges<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = (N, N, &'a E);
fn next(&mut self) -> Option<Self::Item> {
self.inner.next().map(|(&(a, b), v)| (a, b, v))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
fn count(self) -> usize {
self.inner.count()
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
self.inner
.nth(n)
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
fn last(self) -> Option<Self::Item> {
self.inner
.last()
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
}
impl<'a, N, E, Ty> DoubleEndedIterator for AllEdges<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
fn next_back(&mut self) -> Option<Self::Item> {
self.inner
.next_back()
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
}
pub struct AllEdgesMut<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
{
inner: IndexMapIterMut<'a, (N, N), E>, // TODO: change to something that implements Debug + Clone?
ty: PhantomData<Ty>,
}
impl<'a, N, E, Ty> Iterator for AllEdgesMut<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = (N, N, &'a mut E);
fn next(&mut self) -> Option<Self::Item> {
self.inner
.next()
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
fn count(self) -> usize {
self.inner.count()
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
self.inner
.nth(n)
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
fn last(self) -> Option<Self::Item> {
self.inner
.last()
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
}
impl<'a, N, E, Ty> DoubleEndedIterator for AllEdgesMut<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
fn next_back(&mut self) -> Option<Self::Item> {
self.inner
.next_back()
.map(|(&(n1, n2), weight)| (n1, n2, weight))
}
}
/// Index `GraphMap` by node pairs to access edge weights.
impl<N, E, Ty> Index<(N, N)> for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type Output = E;
fn index(&self, index: (N, N)) -> &E {
let index = Self::edge_key(index.0, index.1);
self.edge_weight(index.0, index.1)
.expect("GraphMap::index: no such edge")
}
}
/// Index `GraphMap` by node pairs to access edge weights.
impl<N, E, Ty> IndexMut<(N, N)> for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
fn index_mut(&mut self, index: (N, N)) -> &mut E {
let index = Self::edge_key(index.0, index.1);
self.edge_weight_mut(index.0, index.1)
.expect("GraphMap::index: no such edge")
}
}
/// Create a new empty `GraphMap`.
impl<N, E, Ty> Default for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
fn default() -> Self {
GraphMap::with_capacity(0, 0)
}
}
/// A reference that is hashed and compared by its pointer value.
///
/// `Ptr` is used for certain configurations of `GraphMap`,
/// in particular in the combination where the node type for
/// `GraphMap` is something of type for example `Ptr(&Cell<T>)`,
/// with the `Cell<T>` being `TypedArena` allocated.
pub struct Ptr<'b, T: 'b>(pub &'b T);
impl<'b, T> Copy for Ptr<'b, T> {}
impl<'b, T> Clone for Ptr<'b, T> {
fn clone(&self) -> Self {
*self
}
}
fn ptr_eq<T>(a: *const T, b: *const T) -> bool {
a == b
}
impl<'b, T> PartialEq for Ptr<'b, T> {
/// Ptr compares by pointer equality, i.e if they point to the same value
fn eq(&self, other: &Ptr<'b, T>) -> bool {
ptr_eq(self.0, other.0)
}
}
impl<'b, T> PartialOrd for Ptr<'b, T> {
fn partial_cmp(&self, other: &Ptr<'b, T>) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl<'b, T> Ord for Ptr<'b, T> {
/// Ptr is ordered by pointer value, i.e. an arbitrary but stable and total order.
fn cmp(&self, other: &Ptr<'b, T>) -> Ordering {
let a: *const T = self.0;
let b: *const T = other.0;
a.cmp(&b)
}
}
impl<'b, T> Deref for Ptr<'b, T> {
type Target = T;
fn deref(&self) -> &T {
self.0
}
}
impl<'b, T> Eq for Ptr<'b, T> {}
impl<'b, T> Hash for Ptr<'b, T> {
fn hash<H: hash::Hasher>(&self, st: &mut H) {
let ptr = (self.0) as *const T;
ptr.hash(st)
}
}
impl<'b, T: fmt::Debug> fmt::Debug for Ptr<'b, T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.0.fmt(f)
}
}
#[derive(Debug, Clone)]
pub struct NodeIdentifiers<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
{
iter: IndexMapIter<'a, N, Vec<(N, CompactDirection)>>,
ty: PhantomData<Ty>,
edge_ty: PhantomData<E>,
}
impl<'a, N, E, Ty> Iterator for NodeIdentifiers<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = N;
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|(&n, _)| n)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
#[derive(Debug, Clone)]
pub struct NodeReferences<'a, N, E: 'a, Ty>
where
N: 'a + NodeTrait,
{
iter: IndexMapIter<'a, N, Vec<(N, CompactDirection)>>,
ty: PhantomData<Ty>,
edge_ty: PhantomData<E>,
}
impl<'a, N, E, Ty> Iterator for NodeReferences<'a, N, E, Ty>
where
N: 'a + NodeTrait,
E: 'a,
Ty: EdgeType,
{
type Item = (N, &'a N);
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|(n, _)| (*n, n))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<N, E, Ty> visit::GraphBase for GraphMap<N, E, Ty>
where
N: Copy + PartialEq,
{
type NodeId = N;
type EdgeId = (N, N);
}
impl<N, E, Ty> visit::Data for GraphMap<N, E, Ty>
where
N: Copy + PartialEq,
Ty: EdgeType,
{
type NodeWeight = N;
type EdgeWeight = E;
}
impl<N, E, Ty> visit::Visitable for GraphMap<N, E, Ty>
where
N: Copy + Ord + Hash,
Ty: EdgeType,
{
type Map = HashSet<N>;
fn visit_map(&self) -> HashSet<N> {
HashSet::with_capacity(self.node_count())
}
fn reset_map(&self, map: &mut Self::Map) {
map.clear();
}
}
impl<N, E, Ty> visit::GraphProp for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type EdgeType = Ty;
}
impl<'a, N, E, Ty> visit::IntoNodeReferences for &'a GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type NodeRef = (N, &'a N);
type NodeReferences = NodeReferences<'a, N, E, Ty>;
fn node_references(self) -> Self::NodeReferences {
NodeReferences {
iter: self.nodes.iter(),
ty: self.ty,
edge_ty: PhantomData,
}
}
}
impl<'a, N, E: 'a, Ty> visit::IntoNodeIdentifiers for &'a GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type NodeIdentifiers = NodeIdentifiers<'a, N, E, Ty>;
fn node_identifiers(self) -> Self::NodeIdentifiers {
NodeIdentifiers {
iter: self.nodes.iter(),
ty: self.ty,
edge_ty: PhantomData,
}
}
}
impl<N, E, Ty> visit::NodeCount for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
fn node_count(&self) -> usize {
(*self).node_count()
}
}
impl<N, E, Ty> visit::NodeIndexable for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
fn node_bound(&self) -> usize {
self.node_count()
}
fn to_index(&self, ix: Self::NodeId) -> usize {
let (i, _, _) = self.nodes.get_full(&ix).unwrap();
i
}
fn from_index(&self, ix: usize) -> Self::NodeId {
assert!(
ix < self.nodes.len(),
"The requested index {} is out-of-bounds.",
ix
);
let (&key, _) = self.nodes.get_index(ix).unwrap();
key
}
}
impl<N, E, Ty> visit::NodeCompactIndexable for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
}
impl<'a, N: 'a, E, Ty> visit::IntoNeighbors for &'a GraphMap<N, E, Ty>
where
N: Copy + Ord + Hash,
Ty: EdgeType,
{
type Neighbors = Neighbors<'a, N, Ty>;
fn neighbors(self, n: Self::NodeId) -> Self::Neighbors {
self.neighbors(n)
}
}
impl<'a, N: 'a, E, Ty> visit::IntoNeighborsDirected for &'a GraphMap<N, E, Ty>
where
N: Copy + Ord + Hash,
Ty: EdgeType,
{
type NeighborsDirected = NeighborsDirected<'a, N, Ty>;
fn neighbors_directed(self, n: N, dir: Direction) -> Self::NeighborsDirected {
self.neighbors_directed(n, dir)
}
}
impl<N, E, Ty> visit::EdgeIndexable for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
fn edge_bound(&self) -> usize {
self.edge_count()
}
fn to_index(&self, ix: Self::EdgeId) -> usize {
let (i, _, _) = self.edges.get_full(&ix).unwrap();
i
}
fn from_index(&self, ix: usize) -> Self::EdgeId {
assert!(
ix < self.edges.len(),
"The requested index {} is out-of-bounds.",
ix
);
let (&key, _) = self.edges.get_index(ix).unwrap();
key
}
}
impl<'a, N: 'a, E: 'a, Ty> visit::IntoEdges for &'a GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type Edges = Edges<'a, N, E, Ty>;
fn edges(self, a: Self::NodeId) -> Self::Edges {
self.edges(a)
}
}
impl<'a, N: 'a, E: 'a, Ty> visit::IntoEdgesDirected for &'a GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type EdgesDirected = EdgesDirected<'a, N, E, Ty>;
fn edges_directed(self, a: Self::NodeId, dir: Direction) -> Self::EdgesDirected {
self.edges_directed(a, dir)
}
}
impl<'a, N: 'a, E: 'a, Ty> visit::IntoEdgeReferences for &'a GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
type EdgeRef = (N, N, &'a E);
type EdgeReferences = AllEdges<'a, N, E, Ty>;
fn edge_references(self) -> Self::EdgeReferences {
self.all_edges()
}
}
impl<N, E, Ty> visit::EdgeCount for GraphMap<N, E, Ty>
where
N: NodeTrait,
Ty: EdgeType,
{
#[inline]
fn edge_count(&self) -> usize {
self.edge_count()
}
}
/// The `GraphMap` keeps an adjacency matrix internally.
impl<N, E, Ty> visit::GetAdjacencyMatrix for GraphMap<N, E, Ty>
where
N: Copy + Ord + Hash,
Ty: EdgeType,
{
type AdjMatrix = ();
#[inline]
fn adjacency_matrix(&self) {}
#[inline]
fn is_adjacent(&self, _: &(), a: N, b: N) -> bool {
self.contains_edge(a, b)
}
}