dawgviz

Debugging a suffix automaton? Try this:

echo science | dawgviz | dot -Tsvg -o science.svg

Installation

1. Install Nim.

2. Install LuaJIT.

   On a Debian-based distribution, this is as simple as
   sudo apt install libluajit-5.1-2. On Windows, you’ll probably need to copy luajit.dll to bin\ after building dawgviz.exe.

3. Install Graphviz.

   Strictly speaking, this is optional, but you won’t be able to generate pictures without it.

4. Clone this repository.

5. Run nimble build -d=release.

6. Install the built program.

   On Windows, you’ll need to add bin\ directory to PATH. On Unix, a more idiomatic way is
   make PREFIX=~/.local install or sudo make install. Do not try to install via Nimble: it won’t work.

Usage

Usage:
  dawgviz [-T<fmt>] [-e<code>...] [<custom-formatter>...]
Options:
  -V, --version   Print version.
  -T=, --target=  Select output format (or `-` for none).
  -e=, --eval=    Evaluate Lua code after loading everything.

Different output formats

Use -T option to choose an output format for the graph. dot (used by default) and json formatters are provided:

echo zoom | dawgviz -Tjson

{"i":"zoom","g":[{
"s":"",
"p":-1,
"d":{"o":4,"m":5,"z":1}
},{
"s":"z",
"p":0,
"l":0,
"d":{"o":2}
},{
"s":"zo",
"p":1,
"l":4,
"d":{"o":3}
},{
"s":"zoo",
"p":2,
"l":4,
"d":{"m":5}
},{
"s":"o",
"p":1,
"c":true,
"l":0,
"d":{"m":5,"o":3}
},{
"s":"zoom",
"p":3,
"l":0,
"d":{}
}]}

Configuring the formatter

Use -e option to tweak the behaviour of the selected formatter. Its argument is a piece of Lua code:

echo zoom | dawgviz -e'graph_attrs.rankdir="LR"'
echo zoom | dawgviz -Tjson -e'substring_key=nil'
echo zoom | dawgviz -Tjson -e'prologue="[{"; epilogue="}]"'

Want to know what exactly is available for configuration? Take a look at dot.lua. Remember, you can redeclare anything.

Providing a custom formatter

-e option works great for small one-time tweaks. If, however, you use the same configuration over and over again, it may be more convenient to store it in a file.

#!/usr/bin/env dawgviz

require "dawgviz.target.dot"
node_attrs.shape = "hexagon"
function Node:get_id() return self.id + 1 end -- Emit 1-based indices.

echo zoom | dawgviz my.lua

When a custom formatter is passed, dot will no longer be loaded implicitly.