title: How to print a YACC grammar graph starting from a specific node?
body: <p>I have a vast YACC grammar for processing a family of related standards. I want to print its graph with <code>bison --graph</code> command, but the generated <code>.dot</code> file has over 40 thousand lines.</p>
  
  <p>The graph is so big, <code>xdot</code> and <code>dot</code> tools are unable to render it. I finally managed to generate an output with <code>sfdp</code>, but the resulting image has over 50MB and is simply unintelligible.</p>
  
  <p><img src="https://i.stack.imgur.com/BD8tw.png" alt="Resulting grammar graph"></p>
  
  <p>I am only interested in visualizing a part of the grammar, preferably a subset starting from a specific grammar rule. Is there a way to add such constraints to the graph generation or rendering?</p>