Maintainer	Ivan.Miljenovic@gmail.com
Safe Haskell	None

Data.GraphViz.Types.Monadic

Contents

Creating a generalised DotGraph.
Adding global attributes.
Adding items to the graph.

Description

This module is based upon the dotgen library by Andy Gill: http://hackage.haskell.org/package/dotgen

It provides a monadic interface for constructing generalised Dot graphs. Note that this does not have an instance for DotRepr (e.g. what would be the point of the fromCanonical function, as you can't do anything with the result): it is purely for construction purposes. Use the generalised Dot graph instance for printing, etc.

Note that the generalised Dot graph types are not re-exported, in case it causes a clash with other modules you may choose to import.

The example graph in Data.GraphViz.Types can be written as:

 digraph (Str "G") $ do

    cluster (Int 0) $ do
        graphAttrs [style filled, color LightGray]
        nodeAttrs [style filled, color White]
        "a0" --> "a1"
        "a1" --> "a2"
        "a2" --> "a3"
        graphAttrs [textLabel "process #1"]

    cluster (Int 1) $ do
        nodeAttrs [style filled]
        "b0" --> "b1"
        "b1" --> "b2"
        "b2" --> "b3"
        graphAttrs [textLabel "process #2", color Blue]

    "start" --> "a0"
    "start" --> "b0"
    "a1" --> "b3"
    "b2" --> "a3"
    "a3" --> "end"
    "b3" --> "end"

    node "start" [shape MDiamond]
    node "end" [shape MSquare]

Synopsis

Documentation

type Dot n = DotM n ()Source

The monadic representation of a Dot graph.

data DotM n a Source

The actual monad; as with Dot but allows you to return a value within the do-block. The actual implementation is based upon the Writer monad.

Instances

Monad (DotM n)

data GraphID Source

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