completeScope method

bool completeScope(IntSegmentedTuple action, int scope_rhs_index)

Implementation

bool completeScope(IntSegmentedTuple action, int scope_rhs_index) {
  var kind = scopeRhs(scope_rhs_index);
  if (kind == 0) return true;

  var act = nextStack[nextStackTop];

  if (kind > NT_OFFSET) {
    var lhs_symbol = kind - NT_OFFSET;
    if (baseCheck(act + lhs_symbol) != lhs_symbol) // is there a valid
      // action defined on
      // lhs_symbol?
    {
      return false;
    }
    act = ntAction(act, lhs_symbol);

    //
    // if action is a goto-reduce action, save it as a shift-reduce
    // action.
    //
    action.add(act <= NUM_RULES ? act + ERROR_ACTION : act);
    while (act <= NUM_RULES) {
      nextStackTop -= (rhs(act) - 1);
      act = ntAction(nextStack[nextStackTop], lhs(act));
    }
    nextStackTop++;
    nextStack[nextStackTop] = act;
//System.err.println("Shifting nonterminal " +
//name(nonterminalIndex(lhs_symbol)));
    return completeScope(action, scope_rhs_index + 1);
  }

  //
  // Processing a terminal
  //
  act = tAction(act, kind);
  action.add(act); // save this terminal action
  // assert(act > NUM_RULES);
  if (act < ACCEPT_ACTION) {
    nextStackTop++;
    nextStack[nextStackTop] = act;
//System.err.println("Shifting terminal " + name(terminalIndex(kind)));
    return completeScope(action, scope_rhs_index + 1);
  } else if (act > ERROR_ACTION) {
    act -= ERROR_ACTION;
    do {
      nextStackTop -= (rhs(act) - 1);
      act = ntAction(nextStack[nextStackTop], lhs(act));
    } while (act <= NUM_RULES);
    nextStackTop++;
    nextStack[nextStackTop] = act;
//System.err.println("Shift-reducing terminal " + name(terminalIndex(kind)));
//assert(scopeRhs(scope_rhs_index + 1) == 0);
    return true;
  } else if (act > ACCEPT_ACTION &&
      act < ERROR_ACTION) // conflicting actions?
  {
    var save_action_size = action.size();
    for (var i = act;
        baseAction(i) != 0;
        i++) // consider only shift and shift-reduce actions
    {
      action.reset(save_action_size);
      act = baseAction(i);
      action.add(act); // save this terminal action
      if (act <= NUM_RULES) // Ignore reduce actions
       {
        ;
        }
      else if (act < ACCEPT_ACTION) {
        nextStackTop++;
        nextStack[nextStackTop] = act;
//System.err.println("(2)Shifting terminal " + name(terminalIndex(kind)));
        if (completeScope(action, scope_rhs_index + 1)) return true;
      } else if (act > ERROR_ACTION) {
        act -= ERROR_ACTION;
        do {
          nextStackTop -= (rhs(act) - 1);
          act = ntAction(nextStack[nextStackTop], lhs(act));
        } while (act <= NUM_RULES);
        nextStackTop++;
        nextStack[nextStackTop] = act;
//System.err.println("(2)Shift-reducing terminal " + name(terminalIndex(kind)));
//assert(scopeRhs(scope_rhs_index + 1) == 0);
        return true;
      }
    }
  }

  return false;
}