parser.java

来自「有关编译器的编译器.」· Java 代码 · 共 2,776 行 · 第 1/5 页

/* This file was generated by SableCC (http://www.sablecc.org/). */

package org.sablecc.sablecc.parser;

import org.sablecc.sablecc.lexer.*;
import org.sablecc.sablecc.node.*;
import org.sablecc.sablecc.analysis.*;
import java.util.*;

import java.io.DataInputStream;
import java.io.BufferedInputStream;
import java.io.IOException;

public class Parser
{
  public final Analysis ignoredTokens = new AnalysisAdapter();

  protected Node node;

  private final Lexer lexer;
  private final ListIterator stack = new LinkedList().listIterator();
  private int last_shift;
  private int last_pos;
  private int last_line;
  private Token last_token;
  private final TokenIndex converter = new TokenIndex();
  private final int[] action = new int[2];

  private final static int SHIFT = 0;
  private final static int REDUCE = 1;
  private final static int ACCEPT = 2;
  private final static int ERROR = 3;

  protected void filter() throws ParserException, LexerException, IOException
    {}

  public Parser(Lexer lexer)
  {
    this.lexer = lexer;

    if(actionTable == null)
    {
      try
      {
        DataInputStream s = new DataInputStream(
                              new BufferedInputStream(
                                Parser.class.getResourceAsStream("parser.dat")));

        // read actionTable
        int length = s.readInt();
        actionTable = new int[length][][];
        for(int i = 0; i < actionTable.length; i++)
        {
          length = s.readInt();
          actionTable[i] = new int[length][3];
          for(int j = 0; j < actionTable[i].length; j++)
          {
            for(int k = 0; k < 3; k++)
            {
              actionTable[i][j][k] = s.readInt();
            }
          }
        }

        // read gotoTable
        length = s.readInt();
        gotoTable = new int[length][][];
        for(int i = 0; i < gotoTable.length; i++)
        {
          length = s.readInt();
          gotoTable[i] = new int[length][2];
          for(int j = 0; j < gotoTable[i].length; j++)
          {
            for(int k = 0; k < 2; k++)
            {
              gotoTable[i][j][k] = s.readInt();
            }
          }
        }

        // read errorMessages
        length = s.readInt();
        errorMessages = new String[length];
        for(int i = 0; i < errorMessages.length; i++)
        {
          length = s.readInt();
          StringBuffer buffer = new StringBuffer();

          for(int j = 0; j < length; j++)
          {
            buffer.append(s.readChar());
          }
          errorMessages[i] = buffer.toString();
        }

        // read errors
        length = s.readInt();
        errors = new int[length];
        for(int i = 0; i < errors.length; i++)
        {
          errors[i] = s.readInt();
        }

        s.close();
      }
      catch(Exception e)
      {
        throw new RuntimeException("The file \"parser.dat\" is either missing or corrupted.");
      }
    }
  }

  private int goTo(int index)
  {
    int state = state();
    int low = 1;
    int high = gotoTable[index].length - 1;
    int value = gotoTable[index][0][1];

    while(low <= high)
    {
      int middle = (low + high) / 2;

      if(state < gotoTable[index][middle][0])
      {
        high = middle - 1;
      }
      else if(state > gotoTable[index][middle][0])
      {
        low = middle + 1;
      }
      else
      {
        value = gotoTable[index][middle][1];
        break;
      }
    }

    return value;
  }

  private void push(int state, Node node, boolean filter) throws ParserException, LexerException, IOException
  {
    this.node = node;

    if(filter)
    {
      filter();
    }

    if(!stack.hasNext())
    {
      stack.add(new State(state, this.node));
      return;
    }

    State s = (State) stack.next();
    s.state = state;
    s.node = this.node;
  }

  private int state()
  {
    State s = (State) stack.previous();
    stack.next();
    return s.state;
  }

  private Node pop()
  {
    return (Node) ((State) stack.previous()).node;
  }

  private int index(Switchable token)
  {
    converter.index = -1;
    token.apply(converter);
    return converter.index;
  }

  public Start parse() throws ParserException, LexerException, IOException
  {
    push(0, null, false);

    List ign = null;
    while(true)
    {
      while(index(lexer.peek()) == -1)
      {
        if(ign == null)
        {
          ign = new TypedLinkedList(NodeCast.instance);
        }

        ign.add(lexer.next());
      }

      if(ign != null)
      {
        ignoredTokens.setIn(lexer.peek(), ign);
        ign = null;
      }

      last_pos = lexer.peek().getPos();
      last_line = lexer.peek().getLine();
      last_token = lexer.peek();

      int index = index(lexer.peek());
      action[0] = actionTable[state()][0][1];
      action[1] = actionTable[state()][0][2];

      int low = 1;
      int high = actionTable[state()].length - 1;

      while(low <= high)
      {
        int middle = (low + high) / 2;

        if(index < actionTable[state()][middle][0])
        {
          high = middle - 1;
        }
        else if(index > actionTable[state()][middle][0])
        {
          low = middle + 1;
        }
        else
        {
          action[0] = actionTable[state()][middle][1];
          action[1] = actionTable[state()][middle][2];
          break;
        }
      }

      switch(action[0])
      {
      case SHIFT:
        push(action[1], lexer.next(), true);
        last_shift = action[1];
        break;
      case REDUCE:
        switch(action[1])
        {
        case 0:
          {
            Node node = new0();
            push(goTo(0), node, true);
          }
          break;
        case 1:
          {
            Node node = new1();
            push(goTo(0), node, true);
          }
          break;
        case 2:
          {
            Node node = new2();
            push(goTo(0), node, true);
          }
          break;
        case 3:
          {
            Node node = new3();
            push(goTo(0), node, true);
          }
          break;
        case 4:
          {
            Node node = new4();
            push(goTo(0), node, true);
          }
          break;
        case 5:
          {
            Node node = new5();
            push(goTo(0), node, true);
          }
          break;
        case 6:
          {
            Node node = new6();
            push(goTo(0), node, true);
          }
          break;
        case 7:
          {
            Node node = new7();
            push(goTo(0), node, true);
          }
          break;
        case 8:
          {
            Node node = new8();
            push(goTo(0), node, true);
          }
          break;
        case 9:
          {
            Node node = new9();
            push(goTo(0), node, true);
          }
          break;
        case 10:
          {
            Node node = new10();
            push(goTo(0), node, true);
          }
          break;
        case 11:
          {
            Node node = new11();
            push(goTo(0), node, true);
          }
          break;
        case 12:
          {
            Node node = new12();
            push(goTo(0), node, true);
          }
          break;
        case 13:
          {
            Node node = new13();
            push(goTo(0), node, true);
          }
          break;
        case 14:
          {
            Node node = new14();
            push(goTo(0), node, true);
          }
          break;
        case 15:
          {
            Node node = new15();
            push(goTo(0), node, true);
          }
          break;
        case 16:
          {
            Node node = new16();
            push(goTo(0), node, true);
          }
          break;
        case 17:
          {
            Node node = new17();
            push(goTo(0), node, true);
          }
          break;
        case 18:
          {
            Node node = new18();
            push(goTo(0), node, true);
          }
          break;
        case 19:
          {
            Node node = new19();
            push(goTo(0), node, true);
          }
          break;
        case 20:
          {
            Node node = new20();
            push(goTo(0), node, true);
          }
          break;
        case 21:
          {
            Node node = new21();
            push(goTo(0), node, true);
          }
          break;
        case 22:
          {
            Node node = new22();
            push(goTo(0), node, true);
          }
          break;
        case 23:
          {
            Node node = new23();
            push(goTo(0), node, true);
          }
          break;
        case 24:
          {
            Node node = new24();
            push(goTo(0), node, true);
          }
          break;
        case 25:
          {
            Node node = new25();
            push(goTo(0), node, true);
          }
          break;
        case 26:
          {
            Node node = new26();
            push(goTo(0), node, true);
          }
          break;
        case 27:
          {
            Node node = new27();
            push(goTo(0), node, true);
          }
          break;
        case 28:
          {
            Node node = new28();
            push(goTo(0), node, true);
          }
          break;
        case 29:
          {
            Node node = new29();
            push(goTo(0), node, true);
          }
          break;
        case 30:
          {
            Node node = new30();
            push(goTo(0), node, true);
          }
          break;
        case 31:
          {
            Node node = new31();
            push(goTo(0), node, true);
          }
          break;
        case 32:
          {
            Node node = new32();
            push(goTo(0), node, true);
          }
          break;
        case 33:
          {
            Node node = new33();
            push(goTo(0), node, true);
          }
          break;
        case 34:
          {
            Node node = new34();
            push(goTo(0), node, true);
          }
          break;
        case 35:
          {
            Node node = new35();
            push(goTo(0), node, true);
          }
          break;
        case 36:
          {
            Node node = new36();
            push(goTo(0), node, true);
          }
          break;
        case 37:
          {
            Node node = new37();
            push(goTo(0), node, true);
          }
          break;
        case 38:
          {
            Node node = new38();
            push(goTo(0), node, true);
          }
          break;
        case 39:
          {
            Node node = new39();
            push(goTo(0), node, true);
          }
          break;
        case 40:
          {
            Node node = new40();
            push(goTo(0), node, true);
          }
          break;
        case 41:
          {
            Node node = new41();
            push(goTo(0), node, true);
          }
          break;
        case 42:
          {
            Node node = new42();
            push(goTo(0), node, true);
          }
          break;
        case 43:
          {
            Node node = new43();
            push(goTo(0), node, true);
          }
          break;
        case 44:
          {
            Node node = new44();
            push(goTo(0), node, true);
          }
          break;
        case 45:
          {
            Node node = new45();
            push(goTo(0), node, true);
          }
          break;
        case 46:
          {
            Node node = new46();
            push(goTo(0), node, true);
          }
          break;
        case 47:
          {
            Node node = new47();
            push(goTo(0), node, true);
          }
          break;
        case 48:
          {
            Node node = new48();
            push(goTo(0), node, true);
          }
          break;
        case 49:
          {
            Node node = new49();
            push(goTo(0), node, true);
          }
          break;
        case 50:
          {
            Node node = new50();
            push(goTo(0), node, true);
          }
          break;
        case 51:
          {
            Node node = new51();
            push(goTo(0), node, true);
          }
          break;
        case 52: