1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227

//! **petgraph** is a graph data structure library.
//!
//! - [`Graph`](./graph/struct.Graph.html) which is an adjacency list graph with
//! arbitrary associated data.
//!
//! - [`StableGraph`](./stable_graph/struct.StableGraph.html) is similar
//! to `Graph`, but it keeps indices stable across removals.
//!
//! - [`GraphMap`](./graphmap/struct.GraphMap.html) is an adjacency list graph
//! which is backed by a hash table and the node identifiers are the keys
//! into the table.
//! - [`CSR`](./csr/struct.Csr.html) is a sparse adjacency matrix graph with
//! arbitrary associated data.
//!
//! Optional crate feature: `"serde-1"`, see the Readme for more information.
//!
#![doc(html_root_url = "https://docs.rs/petgraph/0.4/")]

extern crate fixedbitset;
#[cfg(feature = "graphmap")]
extern crate ordermap;

#[cfg(feature = "serde-1")]
extern crate serde;
#[cfg(feature = "serde-1")]
#[macro_use]
extern crate serde_derive;

#[cfg(all(feature = "serde-1", test))]
extern crate itertools;

#[doc(no_inline)]
pub use graph::Graph;

pub use Direction::{Outgoing, Incoming};

#[macro_use]
mod macros;
mod scored;

// these modules define trait-implementing macros
#[macro_use]
pub mod visit;
#[macro_use]
pub mod data;

pub mod algo;
#[cfg(feature = "generate")]
pub mod generate;
#[cfg(feature = "graphmap")]
pub mod graphmap;
mod graph_impl;
pub mod dot;
pub mod unionfind;
mod dijkstra;
mod astar;
pub mod csr;
mod iter_format;
mod iter_utils;
mod isomorphism;
mod traits_graph;
mod util;
#[cfg(feature = "quickcheck")]
mod quickcheck;
#[cfg(feature = "serde-1")]
mod serde_utils;

pub mod prelude;

/// `Graph<N, E, Ty, Ix>` is a graph datastructure using an adjacency list representation.
pub mod graph {
    pub use graph_impl::{
        Edge,
        EdgeIndex,
        EdgeIndices,
        EdgeReference,
        EdgeReferences,
        EdgeWeightsMut,
        Edges,
        Externals,
        Frozen,
        Graph,
        Neighbors,
        Node,
        NodeIndex,
        NodeIndices,
        NodeWeightsMut,
        NodeReferences,
        WalkNeighbors,
        GraphIndex,
        IndexType,
        edge_index,
        node_index,
        DefaultIx,
        DiGraph,
        UnGraph,
    };
}

#[cfg(feature = "stable_graph")]
pub use graph_impl::stable_graph;

macro_rules! copyclone {
    ($name:ident) => {
        impl Clone for $name {
            #[inline]
            fn clone(&self) -> Self { *self }
        }
    }
}

// Index into the NodeIndex and EdgeIndex arrays
/// Edge direction.
#[derive(Copy, Debug, PartialEq, PartialOrd, Ord, Eq, Hash)]
#[repr(usize)]
pub enum Direction {
    /// An `Outgoing` edge is an outward edge *from* the current node.
    Outgoing = 0,
    /// An `Incoming` edge is an inbound edge *to* the current node.
    Incoming = 1
}

copyclone!(Direction);

impl Direction {
    /// Return the opposite `Direction`.
    #[inline]
    pub fn opposite(&self) -> Direction {
        match *self {
            Outgoing => Incoming,
            Incoming => Outgoing,
        }
    }

    /// Return `0` for `Outgoing` and `1` for `Incoming`.
    #[inline]
    pub fn index(&self) -> usize {
        (*self as usize) & 0x1
    }
}

#[doc(hidden)]
pub use Direction as EdgeDirection;

/// Marker type for a directed graph.
#[derive(Copy, Debug)]
pub enum Directed { }
copyclone!(Directed);

/// Marker type for an undirected graph.
#[derive(Copy, Debug)]
pub enum Undirected { }
copyclone!(Undirected);

/// A graph's edge type determines whether is has directed edges or not.
pub trait EdgeType {
    fn is_directed() -> bool;
}

impl EdgeType for Directed {
    #[inline]
    fn is_directed() -> bool { true }
}

impl EdgeType for Undirected {
    #[inline]
    fn is_directed() -> bool { false }
}


/// Convert an element like `(i, j)` or `(i, j, w)` into
/// a triple of source, target, edge weight.
///
/// For `Graph::from_edges` and `GraphMap::from_edges`.
pub trait IntoWeightedEdge<E> {
    type NodeId;
    fn into_weighted_edge(self) -> (Self::NodeId, Self::NodeId, E);
}

impl<Ix, E> IntoWeightedEdge<E> for (Ix, Ix)
    where E: Default
{
    type NodeId = Ix;

    fn into_weighted_edge(self) -> (Ix, Ix, E) {
        let (s, t) = self;
        (s, t, E::default())
    }
}

impl<Ix, E> IntoWeightedEdge<E> for (Ix, Ix, E)
{
    type NodeId = Ix;
    fn into_weighted_edge(self) -> (Ix, Ix, E) {
        self
    }
}

impl<'a, Ix, E> IntoWeightedEdge<E> for (Ix, Ix, &'a E)
    where E: Clone
{
    type NodeId = Ix;
    fn into_weighted_edge(self) -> (Ix, Ix, E) {
        let (a, b, c) = self;
        (a, b, c.clone())
    }
}

impl<'a, Ix, E> IntoWeightedEdge<E> for &'a (Ix, Ix)
    where Ix: Copy, E: Default
{
    type NodeId = Ix;
    fn into_weighted_edge(self) -> (Ix, Ix, E) {
        let (s, t) = *self;
        (s, t, E::default())
    }
}

impl<'a, Ix, E> IntoWeightedEdge<E> for &'a (Ix, Ix, E)
    where Ix: Copy, E: Clone
{
    type NodeId = Ix;
    fn into_weighted_edge(self) -> (Ix, Ix, E) {
        self.clone()
    }
}