graphviz.scala

package object graphviz {

  case class Attribute(key: String, value: String) {
    def render(): String = s"${key} = ${value}"
  }

  case class AttributePlaceholder(str: String){
    def := (other: AttributePlaceholder): Attribute = Attribute(str, other.str)
  }
  implicit def strToAttrPlaceholder(str: String):AttributePlaceholder = AttributePlaceholder(str)

  abstract class Statement

  case class EdgeStatement(
    startNode:  String,
    finishNode: String,
    attributes: Seq[Attribute]
  ) extends Statement {

    def :| (newAttr: Attribute): EdgeStatement = EdgeStatement(startNode, finishNode, attributes :+ newAttr)

    def render(): String = {
      val attrsRendered = attributes map {_.render} mkString ","
      s"${startNode} -- ${finishNode}[${attrsRendered}]"
    }
  }

  case class EdgeStatementPlaceholder(name: String) {
    def --- (other: EdgeStatementPlaceholder) = EdgeStatement(name, other.name, Seq())
  }
  implicit def stringToEsPlaceholder(str: String) = EdgeStatementPlaceholder(str)

  case class Graph(id: String, edges: Seq[EdgeStatement]){
    def render() = {
      val tmp = (edges map {x => s"\t${x.render};\n"} mkString "")
      s"graph ${id} {\n${tmp}}\n"
    }
  }

  def createGraph(id: String, edges: EdgeStatement*) = {
    Graph(id, edges)
  }

}

graphvizio.scala

import graphviz._
import sys.process._
import java.io._

package graphviz {
  package object io {
    def saveGraph(fname: String, pngFName: String, graph: Graph) = {
      val rendered = graph.render
      new PrintWriter(fname) { write(rendered); close }
      s"dot -Tpng ${fname} -o${pngFName}" !
      //println(s"echo \' ${rendered} \' | dot -Tpng -o${fname}")
      //(s"echo ${rendered}") #| (s"dot -Tpng -o${fname}") !
      //println("ls -al" #| "grep Foo" !)
      //println(Seq("echo", "1")  #| "dot -Tpng -otmp.png" !!)
    }
  }
}

main

import graphviz._
import graphviz.io._

object App {

  case class MyClass(x: Int){
    def ---(b: MyClass):(Int, Int) = (x, b.x)
  }
  implicit def intToMyTrait(x:Int): MyClass = MyClass(x)

  def main(args: Array[String]) {
    println("Hi")
    println(1 --- 2)
    //val graph = createGraph("tmp", ("1", "2"), ("2", "3"))
    val graph = createGraph("tmp", "1" --- "2" :| ("color" := "red"))
    println(graph.render)
    saveGraph("tmp2.dot", "tmp2.png", graph)
  }
}