/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * This file is part of SableCC.                             * * See the file "LICENSE" for copyright information and the  * * terms and conditions for copying, distribution and        * * modification of SableCC.                                  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */package org.sablecc.sablecc;import java.util.Vector;import java.util.Enumeration;import java.util.*;final class LR1Collection{  final LR0Collection collection;  final TreeMap[] lookaheads;  private final TreeMap[] propagation;  LR1Collection(LR0ItemSet set                 )  {    collection = new LR0Collection(set                                  );    // Initialize lookaheads to nothing, propagation to nothing    LR0ItemSet[] sets = collection.sets();    lookaheads = new TreeMap[sets.length];    propagation = new TreeMap[sets.length];    for(int i = 0; i < sets.length; i++)    {      System.out.print(".");      lookaheads[i] = new TreeMap();      propagation[i] = new TreeMap();      LR0Item[] items = sets[i].items();      for(int j = 0; j < items.length; j++)      {        lookaheads[i].put(items[j], new SymbolSet());        propagation[i].put(items[j], new Vector(0));      }    }    System.out.println();    ((SymbolSet) lookaheads[0].get(set.items()[0])).setTerminal(Grammar.eof);    for(int i = 0; i < sets.length; i++)    {      System.out.print(".");      LR0Item[] items = sets[i].items();      for(int j = 0; j < items.length; j++)      {        LR1ItemSet lr1Set = new LR1ItemSet();        lr1Set.set(new LR1Item(items[j], Grammar.dummy));        LR1Item[] closure = Grammar.CLOSURE(lr1Set).items();        for(int k = 0; k < closure.length; k++)        {          if(closure[k].terminal != Grammar.dummy)          {            Symbol[] rightside = Production.                                 production(closure[k].lr0Item.production).                                 rightside();            if(closure[k].lr0Item.position < rightside.length)            {              Integer destination = collection.GOTO(i,                                                    rightside[closure[k].lr0Item.position]);              if(destination != null)              {                ((SymbolSet) lookaheads[destination.intValue()].                 get                   (new LR0Item(closure[k].lr0Item.production,                                closure[k].lr0Item.position + 1))).                  setTerminal(closure[k].terminal);                /*((SymbolSet) lookaheads[collection.GOTO(i,                Production.production(closure[k].lr0Item.production).                rightside(closure[k].lr0Item.position)).intValue()].                get(new LR0Item(closure[k].lr0Item.production,                closure[k].lr0Item.position + 1))).                setTerminal(closure[k].terminal);*/              }            }          }          else          {            Symbol[] rightside = Production.                                 production(closure[k].lr0Item.production).                                 rightside();            if(closure[k].lr0Item.position < rightside.length)            {              Integer destination = collection.GOTO(i,                                                    rightside[closure[k].lr0Item.position]);              if(destination != null)              {                ((Vector) propagation[i].get(items[j])).                addElement(new LR0ItemAndSetPair(                             new LR0Item(closure[k].lr0Item.production,                                         closure[k].lr0Item.position + 1),                             destination.intValue()));                /*((Vector) propagation[i].get(items[j])).                    addElement(new LR0ItemAndSetPair(                    new LR0Item(closure[k].lr0Item.production,                    closure[k].lr0Item.position + 1),                    collection.GOTO(i,                    Production.production(closure[k].lr0Item.production).                    rightside(closure[k].lr0Item.position)).intValue()));*/              }            }          }        }      }    }    System.out.println();    boolean changed;    do    {      System.out.print(".");      changed = false;      for(int i = 0; i < sets.length; i++)      {        LR0Item[] items = sets[i].items();        for(int j = 0; j < items.length; j++)        {          for(Enumeration e = ((Vector) propagation[i].get(items[j])).                              elements(); e.hasMoreElements();)          {            LR0ItemAndSetPair pair = (LR0ItemAndSetPair) e.nextElement();            SymbolSet before = (SymbolSet)                               ((SymbolSet) lookaheads[pair.set].get(pair.item)).clone();            ((SymbolSet) lookaheads[pair.set].get(pair.item)).            or((SymbolSet) lookaheads[i].get(items[j]));            if(!before.equals(lookaheads[pair.set].get(pair.item)))            {              changed = true;            }          }        }      }    }    while(changed);    System.out.println();  }  public String toString()  {    StringBuffer result = new StringBuffer();    result.append(collection);    result.append(System.getProperty("line.separator"));    result.append("Lookaheads" + System.getProperty("line.separator"));    LR0ItemSet[] sets = collection.sets();    for(int i = 0; i < sets.length; i++)    {      result.append(i + ":" + System.getProperty("line.separator"));      LR0Item[] items = sets[i].items();      for(int j = 0; j < items.length; j++)      {        result.append(items[j] + ":" + lookaheads[i].get(items[j]) +                      System.getProperty("line.separator"));      }    }    return result.toString();  }}