{ /* initializer - run before general parser runs */ 
  /**
   * Deeply flatten an array.
   * @param  {Array} arr - array to flatten
   * @return {Array} - flattened array
   */
  const flatten = (arr) =>  Array.isArray(arr) ? arr.reduce((flat, elt) => flat.concat(Array.isArray(elt) ? flatten(elt) : elt), []) : arr

  function Node( name ){                     // an individual node 
    this.name = name; 
    this.children = [];                      // ordered list of names 
  } 

  function Tree(){                           // a tree of nodes 
    this.root = new Node('root');            // start from a root node 
    this.ancestors = [];                     // ancestors of last added node 
  } 

  Tree.prototype.addNode = function( indent, name, bullet ){ 
    console.log(bullet);
    this.ancestors.splice( indent );         // trim ancestor tree (if needed) 
    this.current = this.root;                // set current pointer to root 
    this.ancestors.forEach(function(e){      // walk current to node ancestor 
        this.current = this.current[e]; 
        }, this); 
    this.current[name] = new Node( name );   // add node to parent 
    this.current.children.push( name );      // add node name to list of kids 
    this.ancestors.push( name );             // add node to list of ancestors 
  } 

  var tree = new Tree(); 
} 

start   = axis subAxis*                                  { return tree.root; } 
axis    = name:text ( newline / eof )                    { tree.addNode( 0, flatten(name).join("") ); }
subAxis = i:indent b:bullet? name:text t:times? ( newline / eof ) { tree.addNode( i.length, flatten(name).join(""), b); } 
indent  = i:"    "*
bullet  = b:(">" / "|" / "//" / ">=") " "?
times   = "(X" [1-9] ")"
text    = w:(word " "?)+
word    = w:[a-zA-Z0-9\']+
newline = "\r\n" / "\n" / "\r"+                     
eof = !.                                                 { console.log(tree) }