!759

static boolean printNulls = true, full = true;

static L<S> inputs = toLinesFullTrim([[

  hello

  "hello!"

  hello you

  hello < you

  [hello]

  [hello] [you]

  [hello < you]

  [ ? < Is < it < safe < to < allow [PowerTOP] to [make < all < the < changes < located on < the < Tunables < tab] ]

  [ I < was < going to < create < a < startup script < for < it ]

]]);

static S snlRules = [[

  // highest (strongest binding) level 

  <identifier> = idword

  <quoted> = subword

  ? = idword

  ! = idword

  <subword> = word

  <idword> = word

  // juxtaposition on highest level

  <word> <word> = word

  // bracketing takes us to highest level

  [ <lowest> ] = subword

  ( <lowest> ) = subword

  // < is intermediate

  <word> = arrows

  <word> < <arrows> = arrows

  = lowest // allow empty here

  <arrows> = lowest

]];

p {

  for (S input : inputs) {

    Explain exp = full

      ? explainFull(input, snlRules, "lowest")

      : explain(input, snlRules, "lowest");

    print();

    print("PARSING: " + input);

    print();

    if (exp == null)

      print("No parse");

    else {

      //printStructure(exp.e);

      printTree(0, exp);

    }

    print();

  }

}

static void printTree(int indent, Explain e) {

  if (e == null) {

    // this would print "null" for every <identifier> etc

    if (printNulls)

      print(indent(indent) + "null");

  } else {

    print(indent(indent) + e.className() + " | " + e.string());

    for (Explain sub : e.subs)

      printTree(indent+2, sub);

  }

}