Introduction

Parsing and printing for the dot language of graphviz.

• A close rendition of the dot language specification
• Supports inexact printing . parsing round trip; forgetting comments, separator choice and whitespace.
• Treats attribute keys and values as ByteStrings. No Type safety of Attributes is attempted.
• Uses command-line graphviz programs `dot` and `neato` to augment dot graph specifications
• Supports conversion from and to algebraic-graphs.
• Support rendering dot graphs using chart-svg.
• Uses flatparse for speedy parsing.

Reference

Graphviz documentation:

Graphviz Main Page

Graphviz Visual Editor

Attributes | Graphviz

Dot Grammar

Graphviz practical examples:

https://renenyffenegger.ch/notes/tools/Graphviz/examples/index

https://renenyffenegger.ch/notes/tools/Graphviz/attributes/label/HTML-like/index

Similar projects

The graphviz library aims for comprehensive typing of graphviz attributes and syntax. As a result, it is quite large and somewhat incomplete. In contrast, dotparse parsing is simpler, more robust and faster. It is also somewhat tied to fgl and I wanted to try a different graph library.

dotgen is a dot graph printer but not a parser. It supports a monadic style of printing. Specifically, it supports generation of unique names if that is an important feature of the problem domain.

development wish list

Target calligraphy for enhanced source code visualization.

Broaden support to include fgl and containers.

Support parsing of library graphs from cabal.

Explore tagged partial birectional isomorphism style.

Steal design ideas from jordan.

process pipelines

algebraic-graphs

Starting with a Graph from algebraic-graphs:

import qualified Algebra.Graph as G :{ exAGraph :: G.Graph Int exAGraph = G.edges $ [(v, (v + 1) `mod` 6) | v <- [0 .. 5]] <> [(v, v + k) | v <- [0 .. 5], k <- [6, 12]] <> [(2, 18), (2, 19), (15, 18), (15, 19), (18, 3), (19, 3)] :} ghci| ghci| ghci| ghci| ghci| ghci| ghci| exAGraph Overlay (Connect (Vertex 0) (Vertex 1)) (Overlay (Connect (Vertex 1) (Vertex 2)) (Overlay (Connect (Vertex 2) (Vertex 3)) (Overlay (Connect (Vertex 3) (Vertex 4)) (Overlay (Connect (Vertex 4) (Vertex 5)) (Overlay (Connect (Vertex 5) (Vertex 0)) (Overlay (Connect (Vertex 0) (Vertex 6)) (Overlay (Connect (Vertex 0) (Vertex 12)) (Overlay (Connect (Vertex 1) (Vertex 7)) (Overlay (Connect (Vertex 1) (Vertex 13)) (Overlay (Connect (Vertex 2) (Vertex 8)) (Overlay (Connect (Vertex 2) (Vertex 14)) (Overlay (Connect (Vertex 3) (Vertex 9)) (Overlay (Connect (Vertex 3) (Vertex 15)) (Overlay (Connect (Vertex 4) (Vertex 10)) (Overlay (Connect (Vertex 4) (Vertex 16)) (Overlay (Connect (Vertex 5) (Vertex 11)) (Overlay (Connect (Vertex 5) (Vertex 17)) (Overlay (Connect (Vertex 2) (Vertex 18)) (Overlay (Connect (Vertex 2) (Vertex 19)) (Overlay (Connect (Vertex 15) (Vertex 18)) (Overlay (Connect (Vertex 15) (Vertex 19)) (Overlay (Connect (Vertex 18) (Vertex 3)) (Connect (Vertex 19) (Vertex 3)))))))))))))))))))))))) 

dotparse Graph

Convert to a dotparse Graph

exGraph = defaultGraph & addStatements (toStatements Directed (Char8.pack . show <$> exAGraph)) 

dotPrint

Encode graph as a ByteString (prior to processing via graphviz)

BS.putStr (dotPrint defaultDotConfig exGraph) digraph { node [height=0.5;shape=circle] graph [overlap=false;size="1!";splines=spline] edge [arrowsize=0.5] "9" "8" "7" "6" "5" "4" "3" "2" "19" "18" "17" "16" "15" "14" "13" "12" "11" "10" "1" "0" "5" -> "17" "5" -> "11" "5" -> "0" "4" -> "5" "4" -> "16" "4" -> "10" "3" -> "9" "3" -> "4" "3" -> "15" "2" -> "8" "2" -> "3" "2" -> "19" "2" -> "18" "2" -> "14" "19" -> "3" "18" -> "3" "15" -> "19" "15" -> "18" "1" -> "7" "1" -> "2" "1" -> "13" "0" -> "6" "0" -> "12" "0" -> "1" } 

processDotWith

Directly create an SVG from the dotparse Graph

(\b f -> processDotWith Directed ["-Tsvg", "-o", "other/" <> f <> ".svg"] b) (dotPrint defaultDotConfig exGraph) "exdirect" 

processDot

ByteString of the processed Graph

BS.putStr =<< processDot Directed (dotPrint defaultDotConfig exInt) 

processGraph

Graph augmented by graphviz

exGraphAugmented <- processGraph exGraph :t exGraphAugmented exGraphAugmented :: Graph 

graphToChartWith

SVG production via chart-svg

import Chart (writeChartOptions) writeChartOptions "other/exga.svg" (graphToChart exGraphAugmented) 

Development

imports

:reload :set -XOverloadedLabels :set -XOverloadedStrings :set -Wno-type-defaults :set -Wno-x-partial :set -XImportQualifiedPost import Chart import Optics.Core import FlatParse.Basic qualified as FP import qualified Data.ByteString as BS import qualified Data.Text as Text import qualified Data.ByteString.Char8 as Char8 import Algebra.Graph qualified as G import Data.Monoid import GHC.Exts import DotParse import DotParse.Examples import DotParse.Examples.AST import DotParse.Examples.NumHask import Data.Proxy print "ok" [6 of 7] Compiling DotParse.Examples.NumHask ( src/DotParse/Examples/NumHask.hs, interpreted ) [Source file changed] Ok, 7 modules loaded. "ok" 

testAll

Round-trip test

testAll ex0 ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 ex11 ex12 ex13 ex14 ex15 

numhask

g <- processGraph (dotGraphNH Directed) writeChartOptions "other/nh12.svg" (graphToChartWith (defaultChartConfig & set #chartVshift (-4) & set #textSize 12) toLinkNH g) 

chart-svg AST

g1 = dotAST allSC componentEdges BS.writeFile "other/chart-svg-ast.dot" $ dotPrint defaultDotConfig g1 dot other/chart-svg-ast.dot -Tsvg >other/chart-svg-ast.svg