SimpleParser.java

// ===========================================================================
// This file has been generated by
// Rats! Parser Generator, version 2.3.1,
// (C) 2004-2012 Robert Grimm,
// on Tuesday, February 3, 2015 at 9:57:03 AM.
// Edit at your own risk.
// ===========================================================================

import java.io.Reader;
import java.io.IOException;

import xtc.util.Pair;

import xtc.parser.ParserBase;
import xtc.parser.Column;
import xtc.parser.Result;
import xtc.parser.SemanticValue;
import xtc.parser.ParseError;

/**
 * Packrat parser for grammar <code>Simple</code>.
 *
 * <p />This class has been generated by the <i>Rats!</i> parser
 * generator, version 2.3.1, (C) 2004-2012 Robert Grimm.
 */
public final class SimpleParser extends ParserBase {

  // =========================================================================

  /** Memoization table column. */
  static final class SimpleParserColumn extends Column {
    Result frest;
    Result fterm;
  }

  // =========================================================================

  /**
   * Create a new packrat parser.
   *
   * @param reader The reader.
   * @param file The file name.
   */
  public SimpleParser(final Reader reader, final String file) {
    super(reader, file);
  }

  /**
   * Create a new packrat parser.
   *
   * @param reader The file reader.
   * @param file The file name.
   * @param size The file size.
   */
  public SimpleParser(final Reader reader, final String file, final int size) {
    super(reader, file, size);
  }

  // =========================================================================

  protected Column newColumn() {
    return new SimpleParserColumn();
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.program.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  public Result pprogram(final int yyStart) throws IOException {
    Result     yyResult;
    String     yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyResult = pexpr(yyStart);
    yyError  = yyResult.select(yyError);
    if (yyResult.hasValue()) {
      String e = yyResult.semanticValue();

      yyResult = pEOF(yyResult.index);
      yyError  = yyResult.select(yyError);
      if (yyResult.hasValue()) {

        yyValue=e;

        return yyResult.createValue(yyValue, yyError);
      }
    }

    // Done.
    return yyError;
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.expr.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result pexpr(final int yyStart) throws IOException {
    Result     yyResult;
    String     yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyResult = pterm(yyStart);
    yyError  = yyResult.select(yyError);
    if (yyResult.hasValue()) {
      String t = yyResult.semanticValue();

      yyResult = prest(yyResult.index);
      yyError  = yyResult.select(yyError);
      if (yyResult.hasValue()) {
        String r = yyResult.semanticValue();

        yyValue=t+r;

        return yyResult.createValue(yyValue, yyError);
      }
    }

    // Done.
    return yyError;
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.rest.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result prest(final int yyStart) throws IOException {
    SimpleParserColumn yyColumn = (SimpleParserColumn)column(yyStart);
    if (null == yyColumn.frest) yyColumn.frest = prest$1(yyStart);
    return yyColumn.frest;
  }

  /** Actually parse Simple.rest. */
  private Result prest$1(final int yyStart) throws IOException {
    Result     yyResult;
    String     yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyResult = pPLUS(yyStart);
    yyError  = yyResult.select(yyError);
    if (yyResult.hasValue()) {

      yyResult = pterm(yyResult.index);
      yyError  = yyResult.select(yyError);
      if (yyResult.hasValue()) {
        String t = yyResult.semanticValue();

        yyResult = prest(yyResult.index);
        yyError  = yyResult.select(yyError);
        if (yyResult.hasValue()) {
          String r = yyResult.semanticValue();

          yyValue=t+"+"+r;

          return yyResult.createValue(yyValue, yyError);
        }
      }
    }

    // Alternative 2.

    yyResult = pMINUS(yyStart);
    yyError  = yyResult.select(yyError);
    if (yyResult.hasValue()) {

      yyResult = pterm(yyResult.index);
      yyError  = yyResult.select(yyError);
      if (yyResult.hasValue()) {
        String t = yyResult.semanticValue();

        yyResult = prest(yyResult.index);
        yyError  = yyResult.select(yyError);
        if (yyResult.hasValue()) {
          String r = yyResult.semanticValue();

          yyValue=t+"-"+r;

          return yyResult.createValue(yyValue, yyError);
        }
      }
    }

    // Alternative 3.

    yyValue="";

    return new SemanticValue(yyValue, yyStart, yyError);
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.term.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result pterm(final int yyStart) throws IOException {
    SimpleParserColumn yyColumn = (SimpleParserColumn)column(yyStart);
    if (null == yyColumn.fterm) yyColumn.fterm = pterm$1(yyStart);
    return yyColumn.fterm;
  }

  /** Actually parse Simple.term. */
  private Result pterm$1(final int yyStart) throws IOException {
    int        yyC;
    int        yyIndex;
    String     yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyC = character(yyStart);
    if (-1 != yyC) {
      yyIndex = yyStart + 1;

      switch (yyC) {
      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
        {
          yyValue = difference(yyStart, yyIndex);

          return new SemanticValue(yyValue, yyIndex, yyError);
        }

      default:
        /* No match. */
      }
    }

    // Done.
    yyError = yyError.select("term expected", yyStart);
    return yyError;
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.PLUS.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result pPLUS(final int yyStart) throws IOException {
    int        yyC;
    int        yyIndex;
    Void       yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyC = character(yyStart);
    if ('+' == yyC) {
      yyIndex = yyStart + 1;

      yyValue = null;

      return new SemanticValue(yyValue, yyIndex, yyError);
    }

    // Done.
    yyError = yyError.select("PLUS expected", yyStart);
    return yyError;
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.MINUS.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result pMINUS(final int yyStart) throws IOException {
    int        yyC;
    int        yyIndex;
    Void       yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyC = character(yyStart);
    if ('-' == yyC) {
      yyIndex = yyStart + 1;

      yyValue = null;

      return new SemanticValue(yyValue, yyIndex, yyError);
    }

    // Done.
    yyError = yyError.select("MINUS expected", yyStart);
    return yyError;
  }

  // =========================================================================

  /**
   * Parse nonterminal Simple.EOF.
   *
   * @param yyStart The index.
   * @return The result.
   * @throws IOException Signals an I/O error.
   */
  private Result pEOF(final int yyStart) throws IOException {
    int        yyC;
    boolean    yyPredMatched;
    Void       yyValue;
    ParseError yyError = ParseError.DUMMY;

    // Alternative 1.

    yyPredMatched = false;

    yyC = character(yyStart);
    if (-1 != yyC) {

      yyPredMatched = true;
    }

    if (! yyPredMatched) {

      yyValue = null;

      return new SemanticValue(yyValue, yyStart, yyError);
    } else {
      yyError = yyError.select("EOF expected", yyStart);
    }

    // Done.
    return yyError;
  }

}