Copyright	(c) Marcelo Garlet Milani 2026
License	MIT
Maintainer	mgmilani@pm.me
Stability	stable
Safe Haskell	Safe-Inferred
Language	Haskell2010

Nauty

Contents

Graph structure
Parsing
Encoding

Description

This module functions for encoding and decoding graphs in any of the supported formats. In particular, encodeMany is capable of using the incremental sparse6 format as well.

If you want instead to work with a specific format, use Nauty.Graph6, Nauty.Sparse6 or Nauty.Digraph6 instead.

Synopsis

data Graph = Graph {
- numberOfVertices :: Word64
- graphType :: GraphType
- adjacencyList :: UArray Word64 Word64
- adjacencyMatrix :: UArray Word64 Word8
- format :: Format
}
data GraphType
- = Undirected
- | Directed
edgeExists :: Graph -> Word64 -> Word64 -> Bool
toEdgeList :: Graph -> (Word64, [(Word64, Word64)])
data Format
- = Graph6
- | Sparse6
- | Digraph6
- | Incremental
parse :: Text -> [Either Text Graph]
parse' :: Maybe Graph -> [Text] -> [Either Text Graph]
encode :: Graph -> Text
encodeMany :: [Graph] -> Text
encodeMany' :: Maybe Graph -> [Graph] -> [Text]

Graph structure

data Graph Source #

A directed or undirected graph. See nauty documentation for an explanation of the format used by the adjacency matrix.

Constructors

Graph
Fields numberOfVertices :: Word64 graphType :: GraphType adjacencyList :: UArray Word64 Word64 List of edges. Computed from adjacency matrix in graph6 and digraph6 formats. Edges have the form (A[2i], A[2i + 1]), for every i from 0 to half the array size. adjacencyMatrix :: UArray Word64 Word8 Adjacency matrix. Computed from edge list in sparse6 formats. format :: Format

Instances

Instances details

Show Graph Source #
Instance details Defined in Nauty.Internal Methods showsPrec :: Int -> Graph -> ShowS # show :: Graph -> String # showList :: [Graph] -> ShowS #
Eq Graph Source #
Instance details Defined in Nauty.Internal Methods (==) :: Graph -> Graph -> Bool # (/=) :: Graph -> Graph -> Bool #

data GraphType Source #

Whether the graph has undirected or directed edges.

Constructors

Undirected
Directed

Instances

Instances details

Show GraphType Source #
Instance details Defined in Nauty.Internal Methods showsPrec :: Int -> GraphType -> ShowS # show :: GraphType -> String # showList :: [GraphType] -> ShowS #
Eq GraphType Source #
Instance details Defined in Nauty.Internal Methods (==) :: GraphType -> GraphType -> Bool # (/=) :: GraphType -> GraphType -> Bool #

edgeExists Source #

Arguments

:: Graph
-> Word64	From vertex in directed graphs.
-> Word64	To vertex in directed graphs.
-> Bool

Whether the graph contains and edge between two vertices. In digraph6 format, the edge is a directed edge from the first to the second vertex.

toEdgeList :: Graph -> (Word64, [(Word64, Word64)]) Source #

The number of vertices and the list of (potentially directed) edges of a graph.

Parsing

data Format Source #

Format in used for encoding and decoding.

Constructors

Graph6
Sparse6
Digraph6
Incremental

Instances

Instances details

Show Format Source #
Instance details Defined in Nauty.Internal Methods showsPrec :: Int -> Format -> ShowS # show :: Format -> String # showList :: [Format] -> ShowS #
Eq Format Source #
Instance details Defined in Nauty.Internal Methods (==) :: Format -> Format -> Bool # (/=) :: Format -> Format -> Bool #

parse :: Text -> [Either Text Graph] Source #

Parse a list of graphs encoded in graph6, sparse6 or digraph6 format. Each line encodes one graph. Optionally, the first line might be a header of the form >>graph6<<, >>sparse6<< or >>digraph6<<.

parse' Source #

Arguments

:: Maybe Graph	Used in case the first graph of the list uses incremental sparse6 format.
-> [Text]
-> [Either Text Graph]

Parse a list of graphs in graph6, digraph6, sparse6 or incremental sparse6 format.

Encoding

encode :: Graph -> Text Source #

Encode a graph using the format given by the format field. Graphs with the Incremental format are encoded using sparse6.

encodeMany :: [Graph] -> Text Source #

Encode a sequence of graphs using the given formats. Graphs may be encoded with the incremental format, but only if the previous graph is encoded with sparse6.

encodeMany' Source #

Arguments

:: Maybe Graph	Used as a predecessor in case the first graph of the list is to be encoded in incremental sparse6 format.
-> [Graph]
-> [Text]

Encode a sequence of graphs using the given formats. Graphs may be encoded with the incremental format, but only if the previous graph is encoded with sparse6.