jackrusher / arrowic

Quick and dirty directed graph viewer for REPL explorations.

'Arrowic

O frabjous day! Callooh! Callay! Yet another tiny, incomplete clojure wrapper around a Java library!

In this case, the simplest directed graph viewer possible for those situation where you are in the process of interrogating some data and would like to how it looks as boxes and arrows.

I love graphviz as much as the next former-AT&T Research employee, but it's also rather nice to be able to generate an interactive graph layout from within emacs (or whatever your REPL of choice), tinker with it by hand, then export it to SVG.

The default graph style looks like this. There is also a rather large collection of styling options that are currently undocumented. See the arrowic.style namespace to get some idea of how to use styles.

If you’re building a Swing application (hopefully using seesaw), you can create a Swing component to display your graph using the as-swing-component function.

Usage

I'm not currently pushing new versions of this library to Clojars, so you should use it as a git dependency from deps.edn. Once you have it in your project, require whichever parts of the public API you need:

(ns fancy-project
  (:require [arrowic.core :refer [create-graph graph-from-seqs insert-edge! insert-vertex! create-viewer]]))

The easiest way to get a quick graph from your data is probably graph-from-seqs, to which you can pass a sequence of sequences of 2 or 3 items where the first two are nodes and the (optional) third is an edge label. The return value of that function can be passed to create-viewer, which will pop up a new window showing the graph:

(def viewer
  (create-viewer
   (graph-from-seqs [["Clojure" "Lisp" "is-a"]
                     ["Clojure" "functional programming" "supports-paradigm"]])))

If you would rather use the imperative API, a new empty graph can be created using create-graph. The graph thus created can then be mutated in place inside of a with-graph form using insert-vertex! and insert-edge!.

(use '[arrowic.core])

;; grab some words from the UNIX dictionary
(def words
  (into [] (clojure.string/split-lines (slurp "/usr/share/dict/words"))))

;; make a random graph full of words
(defn random-graph []
  (with-graph (create-graph)
    (let [vertices (repeatedly 10 #(insert-vertex! (rand-nth words)))]
      (doseq [edge-label (repeatedly 20 #(rand-nth words))]
        (insert-edge! (rand-nth vertices) 
                      (rand-nth vertices)
                      :label edge-label)))))

(def graph (random-graph))

(def viewer (create-viewer graph))

;; you can re-use a viewer with a new graph like this:
(def another-graph (random-graph))

(view viewer another-graph)

It's also easy to export a graph as an SVG diagram:

(spit "example.svg" (as-svg another-graph))

License

Copyright © 2018-2023 Jack Rusher

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.