processing-pipeline.dot

digraph ProcessingPipeline {
  graph [size="6"];
  splines=ortho;

  edge[fontname="Sans-Serif"]
  node[style=filled, fillcolor=gray90]

  node[fontname="Monospace"]
  tokens [label="[Token]", shape="parallelogram"]
  args [label="[Argument]", shape="parallelogram"]

  node[fontname="Sans-Serif"]
  in [label="CLI Input", shape="parallelogram"]
  refine [label="Refine", shape="rectangle"]
  exec [label="Execute", shape="rectangle"]
  out [label="Output", shape="parallelogram"]
  clispec [
    shape="cylinder",
    label=<
<br/>
CLI Spec<br/>
<br/>
<font point-size="10">  Provided by the user  </font>
>
    ]
  mapping [
    shape="cylinder",
    label=<
<br/>
Argument<br/>
↓<br/>
Function<br/>
<br/>
<font point-size="10">  Provided by the user  </font>
>
    ]

  in -> tokens [label="  Tokenize  "]
  tokens -> refine
  clispec -> refine
  refine -> args
  args -> exec
  mapping -> exec
  exec -> out

  // Align clispec node to the right of refine and on the same level
  refine -> clispec [style=invis]
  clispec -> tokens [style=invis]
  subgraph { rank=same; refine; clispec; }

  // Align mapping node to the right of exec and on the same level
  exec -> mapping [style=invis]
  mapping -> args [style=invis]
  subgraph { rank=same; exec; mapping; }
}