Data.GraphViz.Types

graphviz-2999.18.1.0: Bindings to Graphviz for graph visualisation.

Copyright | (c) Ivan Lazar Miljenovic
License | 3-Clause BSD-style
Maintainer | Ivan.Miljenovic@gmail.com
Safe Haskell | None
Language | Haskell2010

Data.GraphViz.Types

Contents

- Common sub-types
- Helper types for looking up information within a `DotRepr`.
- Obtaining the `DotNode`s and `DotEdges`.
- Printing and parsing a `DotRepr`.
- Limitations and documentation

Description

Four different representations of Dot graphs are available, all of which are based loosely upon the specifications at: http://graphviz.org/doc/info/lang.html. The `DotRepr` class provides a common interface for them (the `PrintDotRepr`, `ParseDotRepr` and `PPDotRepr` classes are used until class aliases are implemented).

Every representation takes in a type parameter: this indicates the node type (e.g. `DotGraph Int` is a Dot graph with integer nodes). Sum types are allowed, though care must be taken when specifying their `ParseDot` instances if there is the possibility of overlapping definitions. The `GraphID` type is an existing sum type that allows textual and numeric values.

If you require using more than one Dot representation, you will most likely need to import at least one of them qualified, as they typically all use the same names.

As a comparison, all four representations provide how you would define the following Dot graph (or at least one isomorphic to it) (the original of which can be found at http://graphviz.org/content/cluster). Note that in all the examples, they are not necessarily done the best way (variables rather than repeated constants, etc.); they are just there to provide a comparison on the structure of each representation.

    digraph G {

      subgraph cluster_0 {
        style=filled;
        color=lightgrey;
        node [style=filled,color=white];
        a0 -> a1 -> a2 -> a3;
        label = "process #1";
      }

      subgraph cluster_1 {
        node [style=filled];
        b0 -> b1 -> b2 -> b3;
        label = "process #2";
        color=blue
      }
      start -> a0;
      start -> b0;
      a1 -> b3;
      b2 -> a3;
      a3 -> a0;
      a3 -> end;
      b3 -> end;

      start [shape=Mdiamond];
      end [shape=Msquare];
    }

Each representation is suited for different things:

Data.GraphViz.Types.Canonical
  is ideal for converting other graph-like data structures into Dot graphs (the Data.GraphViz module provides some functions for this). It is a structured representation of Dot code.
Data.GraphViz.Types.Generalised
  matches the actual structure of Dot code. As such, it is suited for parsing in existing Dot code.
Data.GraphViz.Types.Graph
  provides graph operations for manipulating Dot graphs; this is suited when you want to edit existing Dot code. It uses generalised Dot graphs for parsing and canonical Dot graphs for printing.
Data.GraphViz.Types.Monadic
  is a much easier representation to use when defining relatively static Dot graphs in Haskell code, and looks vaguely like actual Dot code if you squint a bit.

Please also read the limitations section at the end for advice on how to properly use these Dot representations.

Synopsis

- class Ord n => DotRepr dg n where
  - fromCanonical :: DotGraph n -> dg n
  - getID :: dg n -> Maybe GraphID
  - setID :: GraphID -> dg n -> dg n
  - graphIsDirected :: dg n -> Bool
  - setIsDirected :: Bool -> dg n -> dg n
  - graphIsStrict :: dg n -> Bool
  - setStrictness :: Bool -> dg n -> dg n
  - mapDotGraph :: DotRepr dg n' => (n -> n') -> dg n -> dg n'
  - graphStructureInformation :: dg n -> (GlobalAttributes, ClusterLookup)
  - nodeInformation :: Bool -> dg n -> NodeLookup n
  - edgeInformation :: Bool -> dg n -> [DotEdge n]
  - unAnonymise :: dg n -> dg n
- class PrintDot a where
  - unqtDot :: a -> DotCode
  - toDot :: a -> DotCode
  - unqtListToDot :: [a] -> DotCode
  - listToDot :: [a] -> DotCode
- class ParseDot a where
  - parseUnqt :: Parse a
  - parse :: Parse a
  - parseUnqtList :: Parse [a]
  - parseList :: Parse [a]
- class (DotRepr dg n, PrintDot (dg n)) => PrintDotRepr dg n
- class (DotRepr dg n, ParseDot (dg n)) => ParseDotRepr dg n
- class (PrintDotRepr dg n, ParseDotRepr dg n) => PPDotRepr dg n
- data GraphID
  - = Str Text
  - | Num Number
- data Number
  - = Int Int
  - | Dbl Double
- class ToGraphID a where
  - toGraphID :: a -> GraphID
- textGraphID :: Text -> GraphID
- data GlobalAttributes
  - = GraphAttrs {
    - attrs :: Attributes
    }
  - | NodeAttrs {
    - attrs :: Attributes
    }
  - | EdgeAttrs {
    - attrs :: Attributes
    }
- data DotNode n = DotNode {
  - nodeID :: n
  - nodeAttributes :: Attributes
  }
- data DotEdge n = DotEdge {
  - fromNode :: n
  - toNode :: n
  - edgeAttributes :: Attributes
  }
- type ClusterLookup = Map (Maybe GraphID) ([Path], GlobalAttributes)
- type NodeLookup n = Map n (Path, Attributes)
- type Path = Seq (Maybe GraphID)
- graphStructureInformationClean :: DotRepr dg n => dg n -> (GlobalAttributes, ClusterLookup)
- nodeInformationClean :: DotRepr dg n => Bool -> dg n -> NodeLookup n
- edgeInformationClean :: DotRepr dg n => Bool -> dg n -> [DotEdge n]
- graphNodes :: DotRepr dg n => dg n -> [DotNode n]
- graphEdges :: DotRepr dg n => dg n -> [DotEdge n]
- printDotGraph :: PrintDotRepr dg n => dg n -> Text
- parseDotGraph :: ParseDotRepr dg n => Text -> dg n
- parseDotGraphLiberally :: ParseDotRepr dg n => Text -> dg n

# Documentation

class Ord n => DotRepr dg n where

This class is used to provide a common interface to different ways of representing a graph in Dot form.

You will most probably not need to create your own instances of this class.

The type variable represents the current node type of the Dot graph, and the `Ord` restriction is there because in practice most implementations of some of these methods require it.

Methods

fromCanonical :: DotGraph n -> dg n

Convert from a graph in canonical form. This is especially useful when using the functions from Data.GraphViz.Algorithms.

See `FromGeneralisedDot` in Data.GraphViz.Types.Generalised for a semi-inverse of this function.

getID :: dg n -> Maybe GraphID

Return the ID of the graph.

setID :: GraphID -> dg n -> dg n

Set the ID of the graph.

graphIsDirected :: dg n -> Bool

Is this graph directed?

setIsDirected :: Bool -> dg n -> dg n

Set whether a graph is directed or not.

graphIsStrict :: dg n -> Bool

Is this graph strict? Strict graphs disallow multiple edges.

setStrictness :: Bool -> dg n -> dg n

A strict graph disallows multiple edges.

mapDotGraph :: DotRepr dg n' => (n -> n') -> dg n -> dg n'

Change the node values. This function is assumed to be injective, otherwise the resulting graph will not be identical to the original (modulo labels).

graphStructureInformation :: dg n -> (GlobalAttributes, ClusterLookup)

Return information on all the clusters contained within this `DotRepr`, as well as the top-level `GraphAttrs` for the overall graph.

nodeInformation :: Bool -> dg n -> NodeLookup n

Return information on the `DotNode`s contained within this `DotRepr`. The `Bool` parameter indicates if applicable `NodeAttrs` should be included.

edgeInformation :: Bool -> dg n -> [DotEdge n]

Return information on the `DotEdge`s contained within this `DotRepr`. The `Bool` parameter indicates if applicable `EdgeAttrs` should be included.

unAnonymise :: dg n -> dg n

Give any anonymous sub-graphs or clusters a unique identifier (i.e. there will be no `Nothing` key in the `ClusterLookup` from `graphStructureInformation`).

Instances

Ord n => DotRepr DotGraph n |
Ord n => DotRepr DotGraph n |
Ord n => DotRepr DotGraph n |

class PrintDot a where

A class used to correctly print parts of the Graphviz Dot language. Minimal implementation is `unqtDot`.

Minimal complete definition

unqtDot

Methods

unqtDot :: a -> DotCode

The unquoted representation, for use when composing values to produce a larger printing value.

toDot :: a -> DotCode

The actual quoted representation; this should be quoted if it contains characters not permitted a plain ID String, a number or it is not an HTML string. Defaults to `unqtDot`.

unqtListToDot :: [a] -> DotCode

The correct way of representing a list of this value when printed; not all Dot values require this to be implemented. Defaults to Haskell-like list representation.

listToDot :: [a] -> DotCode

The quoted form of `unqtListToDot`; defaults to wrapping double quotes around the result of `unqtListToDot` (since the default implementation has characters that must be quoted).

Instances

PrintDot Bool |
PrintDot Char |
PrintDot Double |
PrintDot Int |
PrintDot Integer |
PrintDot Word8 |
PrintDot Word16 |
PrintDot Version | Ignores `versionTags` and assumes 'not . null . versionBranch' (usually you want 'length . versionBranch == 2').
PrintDot Text |
PrintDot BrewerName |
PrintDot BrewerScheme |
PrintDot ColorScheme |
PrintDot GraphvizCommand |
PrintDot X11Color |
PrintDot CompassPoint |
PrintDot PortPos |
PrintDot PortName |
PrintDot SVGColor |
PrintDot ArrowSide |
PrintDot ArrowFill |
PrintDot ArrowModifier |
PrintDot ArrowShape |
PrintDot ArrowType |
PrintDot WeightedColor |
PrintDot Color |
PrintDot Scale |
PrintDot VAlign |
PrintDot Align |
PrintDot Attribute |
PrintDot Img |
PrintDot Cell |
PrintDot Row |
PrintDot Table |
PrintDot Format |
PrintDot TextItem |
PrintDot Label |
PrintDot NodeSize |
PrintDot Normalized |
PrintDot Number |
PrintDot Ratios |
PrintDot Justification |
PrintDot ScaleType |
PrintDot Paths |
PrintDot VerticalPlacement |
PrintDot FocusType |
PrintDot ViewPort |
PrintDot StyleName |
PrintDot StyleItem |
PrintDot STStyle |
PrintDot StartType |
PrintDot SmoothType |
PrintDot Shape |
PrintDot RankDir |
PrintDot RankType |
PrintDot Root |
PrintDot QuadType |
PrintDot Spline |
PrintDot PageDir |
PrintDot EdgeType |
PrintDot Pos |
PrintDot PackMode |
PrintDot Pack |
PrintDot OutputMode |
PrintDot Order |
PrintDot LayerList |
PrintDot LayerID |
PrintDot LayerRangeElem |
PrintDot LayerListSep |
PrintDot LayerSep |
PrintDot Overlap |
PrintDot Point |
PrintDot LabelScheme |
PrintDot RecordField |
PrintDot Label |
PrintDot Model |
PrintDot ModeType |
PrintDot GraphSize |
PrintDot SVGFontNames |
PrintDot DPoint |
PrintDot DEConstraints |
PrintDot DirType |
PrintDot ClusterMode |
PrintDot Rect |
PrintDot Attribute |
PrintDot GlobalAttributes |
PrintDot GraphID |
PrintDot a => PrintDot [a] |
PrintDot n => PrintDot (DotEdge n) |
PrintDot n => PrintDot (DotNode n) |
PrintDot n => PrintDot (DotSubGraph n) |
PrintDot n => PrintDot (DotStatements n) |
PrintDot n => PrintDot (DotGraph n) |
PrintDot n => PrintDot (DotSubGraph n) |
PrintDot n => PrintDot (DotStatement n) |
PrintDot n => PrintDot (DotGraph n) |
PrintDot n => PrintDot (DotGraph n) | Uses the PrintDot instance for canonical `DotGraph`s.

class ParseDot a where

Minimal complete definition

parseUnqt

Methods

parseUnqt :: Parse a

parse :: Parse a

parseUnqtList :: Parse [a]

parseList :: Parse [a]

Instances

ParseDot Bool |
ParseDot Char |
ParseDot Double |
ParseDot Int |
ParseDot Integer |
ParseDot Word8 |
ParseDot Word16 |
ParseDot Version | Ignores `versionTags` and assumes 'not . null . versionBranch' (usually you want 'length . versionBranch == 2') and that all such values are non-negative.
ParseDot Text |
ParseDot BrewerName |
ParseDot BrewerScheme |
ParseDot ColorScheme |
ParseDot GraphvizCommand |
ParseDot X11Color |
ParseDot CompassPoint |
ParseDot PortPos |
ParseDot PortName |
ParseDot SVGColor |
ParseDot ArrowSide |
ParseDot ArrowFill |
ParseDot ArrowModifier |
ParseDot ArrowShape |
ParseDot ArrowType |
ParseDot WeightedColor |
ParseDot Color |
ParseDot Scale |
ParseDot VAlign |
ParseDot Align |
ParseDot Attribute |
ParseDot Img |
ParseDot Cell |
ParseDot Row |
ParseDot Table |
ParseDot Format |
ParseDot TextItem |
ParseDot Label |
ParseDot NodeSize |
ParseDot Normalized |
ParseDot Number |
ParseDot Ratios |
ParseDot Justification |
ParseDot ScaleType |
ParseDot Paths |
ParseDot VerticalPlacement |
ParseDot FocusType |
ParseDot ViewPort |
ParseDot StyleName |
ParseDot StyleItem |
ParseDot STStyle |
ParseDot StartType |
ParseDot SmoothType |
ParseDot Shape |
ParseDot RankDir |
ParseDot RankType |
ParseDot Root |
ParseDot QuadType |
ParseDot Spline |
ParseDot PageDir |
ParseDot EdgeType |
ParseDot Pos |
ParseDot PackMode |
ParseDot Pack |
ParseDot OutputMode |
ParseDot Order |
ParseDot LayerList |
ParseDot LayerID |
ParseDot LayerRangeElem |
ParseDot LayerListSep |
ParseDot LayerSep |
ParseDot Overlap | Note that `overlap=false` defaults to ``PrismOverlap` Nothing`, but if the Prism library isn't available then it is equivalent to `VoronoiOverlap`.
ParseDot Point |
ParseDot LabelScheme |
ParseDot RecordField |
ParseDot Label |
ParseDot Model |
ParseDot ModeType |
ParseDot GraphSize |
ParseDot SVGFontNames |
ParseDot DPoint |
ParseDot DEConstraints |
ParseDot DirType |
ParseDot ClusterMode |
ParseDot Rect |
ParseDot Attribute |
ParseDot GlobalAttributes |
ParseDot GraphID |
ParseDot a => ParseDot [a] |
ParseDot n => ParseDot (DotEdge n) |
ParseDot n => ParseDot (DotNode n) |
ParseDot n => ParseDot (DotSubGraph n) |
ParseDot n => ParseDot (DotStatements n) |
ParseDot n => ParseDot (DotGraph n) |
ParseDot n => ParseDot (DotSubGraph n) |
ParseDot n => ParseDot (DotStatement n) |
ParseDot n => ParseDot (DotGraph n) |
(Ord n, ParseDot n) => ParseDot (DotGraph n) | Uses the ParseDot instance for generalised `DotGraph`s.

class (DotRepr dg n, PrintDot (dg n)) => PrintDotRepr dg n

This class exists just to make type signatures nicer; all instances of `DotRepr` should also be an instance of `PrintDotRepr`.

Instances

(Ord n, PrintDot n) => PrintDotRepr DotGraph n |
(Ord n, PrintDot n) => PrintDotRepr DotGraph n |
(Ord n, PrintDot n) => PrintDotRepr DotGraph n |

class (DotRepr dg n, ParseDot (dg n)) => ParseDotRepr dg n

This class exists just to make type signatures nicer; all instances of `DotRepr` should also be an instance of `ParseDotRepr`.

Instances

(Ord n, ParseDot n) => ParseDotRepr DotGraph n |
(Ord n, ParseDot n) => ParseDotRepr DotGraph n |
(Ord n, ParseDot n) => ParseDotRepr DotGraph n |

class (PrintDotRepr dg n, ParseDotRepr dg n) => PPDotRepr dg n

This class exists just to make type signatures nicer; all instances of `DotRepr` should also be an instance of `PPDotRepr`.

Instances

(Ord n, PrintDot n, ParseDot n) => PPDotRepr DotGraph n |
(Ord n, PrintDot n, ParseDot n) => PPDotRepr DotGraph n |
(Ord n, PrintDot n, ParseDot n) => PPDotRepr DotGraph n |

# Common sub-types

data GraphID

A polymorphic type that covers all possible ID values allowed by Dot syntax. Note that whilst the `ParseDot` and `PrintDot` instances for `String` will properly take care of the special cases for numbers, they are treated differently here.

Constructors

Str Text |
Num Number |

Instances

Eq GraphID |
Ord GraphID |
Read GraphID |
Show GraphID |
ParseDot GraphID |
PrintDot GraphID |

data Number

A numeric type with an explicit separation between integers and floating-point values.

Constructors

Int Int |
Dbl Double |

Instances

Eq Number |
Ord Number |
Read Number |
Show Number |
ParseDot Number |
PrintDot Number |

class ToGraphID a where

A convenience class to make it easier to convert data types to `GraphID` values, e.g. for cluster identifiers.

In most cases, conversion would be via the `Text` or `String` instances (e.g. using `show`).

Methods

toGraphID :: a -> GraphID

Instances

ToGraphID Char |
ToGraphID Double |
ToGraphID Int |
ToGraphID Integer | This instance loses precision by going via `Int`.
ToGraphID String |
ToGraphID Text |

textGraphID :: Text -> GraphID

An alias for `toGraphID` for use with the `OverloadedStrings` extension.

data GlobalAttributes

Represents a list of top-level list of `Attribute`s for the entire graph/sub-graph. Note that `GraphAttrs` also applies to `DotSubGraph`s.

Note that Dot allows a single `Attribute` to be listed on a line; if this is the case then when parsing, the type of `Attribute` it is determined and that type of `GlobalAttribute` is created.

Constructors

GraphAttrs |
Fields attrs :: Attributes
NodeAttrs |
Fields attrs :: Attributes
EdgeAttrs |
Fields attrs :: Attributes

Instances

Eq GlobalAttributes |
Ord GlobalAttributes |
Read GlobalAttributes |
Show GlobalAttributes |
ParseDot GlobalAttributes |
PrintDot GlobalAttributes |

data DotNode n

A node in `DotGraph`.

Constructors

DotNode |
Fields nodeID :: n nodeAttributes :: Attributes

Instances

Functor DotNode |
Eq n => Eq (DotNode n) |
Ord n => Ord (DotNode n) |
Read n => Read (DotNode n) |
Show n => Show (DotNode n) |
ParseDot n => ParseDot (DotNode n) |
PrintDot n => PrintDot (DotNode n) |

data DotEdge n

An edge in `DotGraph`.

Constructors

DotEdge |
Fields fromNode :: n toNode :: n edgeAttributes :: Attributes

Instances

Functor DotEdge |
Eq n => Eq (DotEdge n) |
Ord n => Ord (DotEdge n) |
Read n => Read (DotEdge n) |
Show n => Show (DotEdge n) |
ParseDot n => ParseDot (DotEdge n) |
PrintDot n => PrintDot (DotEdge n) |

# Helper types for looking up information within a `DotRepr`.

type ClusterLookup = Map (Maybe GraphID) ([Path], GlobalAttributes)

The available information for each cluster; the `[`Path`]` denotes all locations where that particular cluster is located (more than one location can indicate possible problems).

type NodeLookup n = Map n (Path, Attributes)

The available information on each `DotNode` (both explicit and implicit).

type Path = Seq (Maybe GraphID)

The path of clusters that must be traversed to reach this spot.

graphStructureInformationClean :: DotRepr dg n => dg n -> (GlobalAttributes, ClusterLookup)

A variant of `graphStructureInformation` with default attributes removed and only attributes usable by graph/cluster kept (where applicable).

nodeInformationClean :: DotRepr dg n => Bool -> dg n -> NodeLookup n

A variant of `nodeInformation` with default attributes removed and only attributes used by nodes kept.

edgeInformationClean :: DotRepr dg n => Bool -> dg n -> [DotEdge n]

A variant of `edgeInformation` with default attributes removed and only attributes used by edges kept.

# Obtaining the `DotNode`s and `DotEdges`.

graphNodes :: DotRepr dg n => dg n -> [DotNode n]

Returns all resultant `DotNode`s in the `DotRepr` (not including `NodeAttr`s).

graphEdges :: DotRepr dg n => dg n -> [DotEdge n]

Returns all resultant `DotEdge`s in the `DotRepr` (not including `EdgeAttr`s).

# Printing and parsing a `DotRepr`.

printDotGraph :: PrintDotRepr dg n => dg n -> Text

The actual Dot code for an instance of `DotRepr`. Note that it is expected that ``parseDotGraph` . `printDotGraph` == `id`` (this might not be true the other way around due to un-parseable components).

parseDotGraph :: ParseDotRepr dg n => Text -> dg n

Parse a limited subset of the Dot language to form an instance of `DotRepr`. Each instance may have its own limitations on what may or may not be parseable Dot code.

Also removes any comments, etc. before parsing.

parseDotGraphLiberally :: ParseDotRepr dg n => Text -> dg n

As with `parseDotGraph`, but if an `Attribute` cannot be parsed strictly according to the known rules, let it fall back to being parsed as an `UnknownAttribute`. This is especially useful for when using a version of Graphviz that is either newer (especially for the XDot attributes) or older (when some attributes have changed) but you'd still prefer it to parse rather than throwing an error.

# Limitations and documentation

Printing of Dot code is done as strictly as possible, whilst parsing is as permissive as possible. For example, if the types allow it then `"2"` will be parsed as an `Int` value. Note that quoting and escaping of textual values is done automagically.

A summary of known limitations/differences:

- When creating `GraphID` values for graphs and sub-graphs, you should ensure that none of them have the same printed value as one of the node identifiers values to avoid any possible problems.
- If you want any `GlobalAttributes` in a sub-graph and want them to only apply to that sub-graph, then you must ensure it does indeed have a valid `GraphID`.
- All sub-graphs which represent clusters should have unique identifiers (well, only if you want them to be generated sensibly).
- If eventually outputting to a format such as SVG, then you should make sure to specify an identifier for the overall graph, as that is used as the title of the resulting image.
- Whilst the graphs, etc. are polymorphic in their node type, you should ensure that you use a relatively simple node type (that is, it only covers a single line, etc.).
- Also, whilst Graphviz allows you to mix the types used for nodes, this library requires/assumes that they are all the same type (but you can use a sum-type).
- `DotEdge` defines an edge `(a, b)` (with an edge going from `a` to `b`); in Dot parlance the edge has a head at `a` and a tail at `b`. Care must be taken when using the related `Head*` and `Tail*` `Attribute`s. See the differences section in Data.GraphViz.Attributes for more information.
- It is common to see multiple edges defined on the one line in Dot (e.g. `n1 -> n2 -> n3` means to create a directed edge from `n1` to `n2` and from `n2` to `n3`). These types of edge definitions are parseable; however, they are converted to singleton edges.
- It is not yet possible to create or parse edges with subgraphs/clusters as one of the end points.
- The parser will strip out comments and pre-processor lines, join together multiline statements and concatenate split strings together. However, pre-processing within HTML-like labels is currently not supported.
- Graphviz allows a node to be "defined" twice (e.g. the actual node definition, and then in a subgraph with extra global attributes applied to it). This actually represents the same node, but when parsing they will be considered as separate `DotNode`s (such that `graphNodes` will return both "definitions"). `canonicalise` from Data.GraphViz.Algorithms can be used to fix this.

See Data.GraphViz.Attributes.Complete for more limitations.