JavaCompilerCore/tools/skeleton

#	jay skeleton

#	character in column 1 determines outcome...
#		# is a comment
#		. is copied
#		t is copied as //t if -t is set
#	other lines are interpreted to call jay procedures

.// created by jay 0.7 (c) 1998 Axel.Schreiner@informatik.uni-osnabrueck.de
.
 prolog		## %{ ... %} prior to the first %%

.// %token constants
. //{                                                       //ergaenzt PL 23.01.01 wieder entfernt 21.12.01
 tokens public static final int
.
.  /** thrown for irrecoverable syntax errors and stack overflow.
.    */
.  public static class yyException extends java.lang.Exception {
.    public Token token;
.    public yyException (String message, Token token) {
.      super(message);
.      this.token=token;
.    }
.  }
.
.  /** must be implemented by a scanner object to supply input to the parser.
.    */
.  public interface yyInput {
.    /** move on to next token.
.        @return false if positioned beyond tokens.
.        @throws IOException on input error.
.      */
.    boolean advance () throws java.io.IOException;
.    /** classifies current token.
.        Should not be called if advance() returned false.
.        @return current %token or single character.
.      */
.    int token ();
.    /** associated with current token.
.        Should not be called if advance() returned false.
.        @return value for token().
.      */
.    Object value ();
.  }
.
.  /** simplified error message.
.      @see <a href="#yyerror(java.lang.String, java.lang.String[])">yyerror</a>
.    */
.  public void yyerror (String message) {
.    yyerror(message, null);
.  }
.
.  /** (syntax) error message.
.      Can be overwritten to control message format.
.      @param message text to be displayed.
.      @param expected vector of acceptable tokens, if available.
.    */
.  public String yyerror (String message, String[] expected) {
.    if (expected != null && expected.length > 0) {
.      System.err.print(message+", expecting");
.      message+=", expecting";
.      for (int n = 0; n < expected.length; ++ n){
.        System.err.print(" "+expected[n]);
.        message+=" "+expected[n];}
.      System.err.println();
.      return message;
.    } else{
.      System.err.println(message);
.      return message;}
.  }
.
.  /** debugging support, requires the package jay.yydebug.
.      Set to null to suppress debugging messages.
.    */
t  protected jay.yydebug.yyDebug yydebug;
.
 debug			## tables for debugging support
.
.  /** index-checked interface to yyName[].
.      @param token single character or %token value.
.      @return token name or [illegal] or [unknown].
.    */
t  public static final String yyname (int token) {
t    if (token < 0 || token > yyName.length) return "[illegal]";
t    String name;
t    if ((name = yyName[token]) != null) return name;
t    return "[unknown]";
t  }
.
.  /** computes list of expected tokens on error by tracing the tables.
.      @param state for which to compute the list.
.      @return list of token names.
.    */
.  protected String[] yyExpecting (int state) {
.  //  yyCheck durch yyCheckInit.yyCheck;  ersetzt PL 25.1.01
.    int token, n, len = 0;
.    boolean[] ok = new boolean[yyName.length];
.
.    if ((n = yySindex[state]) != 0)
.      for (token = n < 0 ? -n : 0;
.           token < yyName.length && n+token < yyTable.length; ++ token)
.        if (yyCheckInit.yyCheck[n+token] == token && !ok[token] && yyName[token] != null) {
.          ++ len;
.          ok[token] = true;
.        }
.    if ((n = yyRindex[state]) != 0)
.      for (token = n < 0 ? -n : 0;
.           token < yyName.length && n+token < yyTable.length; ++ token)
.        if (yyCheckInit.yyCheck[n+token] == token && !ok[token] && yyName[token] != null) {
.          ++ len;
.          ok[token] = true;
.        }
.
.    String result[] = new String[len];
.    for (n = token = 0; n < len;  ++ token)
.      if (ok[token]) result[n++] = yyName[token];
.    return result;
.  }
.
.  /** the generated parser, with debugging messages.
.      Maintains a state and a value stack, currently with fixed maximum size.
.      @param yyLex scanner.
.      @param yydebug debug message writer implementing yyDebug, or null.
.      @return result of the last reduction, if any.
.      @throws yyException on irrecoverable parse error.
.    */
.  public Object yyparse (yyInput yyLex, Object yydebug)
.				throws java.io.IOException, yyException {
t    this.yydebug = (jay.yydebug.yyDebug)yydebug;
.    return yyparse(yyLex);
.  }
.
.  /** initial size and increment of the state/value stack [default 256].
.      This is not final so that it can be overwritten outside of invocations
.      of yyparse().
.    */
.  protected int yyMax;
.
.  /** executed at the beginning of a reduce action.
.      Used as $$ = yyDefault($1), prior to the user-specified action, if any.
.      Can be overwritten to provide deep copy, etc.
.      @param first value for $1, or null.
.      @return first.
.    */
.  protected Object yyDefault (Object first) {
.    return first;
.  }
.
.  /** the generated parser.
.      Maintains a state and a value stack, currently with fixed maximum size.
.      @param yyLex scanner.
.      @return result of the last reduction, if any.
.      @throws yyException on irrecoverable parse error.
.    */
.  public Object yyparse (yyInput yyLex)
.				throws java.io.IOException, yyException {
.  //  yyCheck durch yyCheckInit.yyCheck;  ersetzt PL 23.1.01
.    yyCheckInit.yyCheckInit();                         // initial yyCheck eingefuegt PL 25.1.01
.    if (yyMax <= 0) yyMax = 256;			// initial size
.    int yyState = 0, yyStates[] = new int[yyMax];	// state stack
.    Object yyVal = null, yyVals[] = new Object[yyMax];	// value stack
.    int yyToken = -1;					// current input
.    int yyErrorFlag = 0;				// #tks to shift
.    Scanner yyScanner = (Scanner)yyLex;
.    String yyErrorString = "irrecoverable syntax error";
.
 local		## %{ ... %} after the first %%

.    yyLoop: for (int yyTop = 0;; ++ yyTop) {
.      if (yyTop >= yyStates.length) {			// dynamically increase
.        int[] i = new int[yyStates.length+yyMax];
.        System.arraycopy(yyStates, 0, i, 0, yyStates.length);
.        yyStates = i;
.        Object[] o = new Object[yyVals.length+yyMax];
.        System.arraycopy(yyVals, 0, o, 0, yyVals.length);
.        yyVals = o;
.      }
.      yyStates[yyTop] = yyState;
.      yyVals[yyTop] = yyVal;
t      if (yydebug != null) yydebug.push(yyState, yyVal);
.
.      yyDiscarded: for (;;) {	// discarding a token does not change stack
.        int yyN;
.        if ((yyN = yyDefRed[yyState]) == 0) {	// else [default] reduce (yyN)
.          if (yyToken < 0) {
.            yyToken = yyLex.advance() ? yyLex.token() : 0;
t            if (yydebug != null)
t              yydebug.lex(yyState, yyToken, yyname(yyToken), yyLex.value());
.          }
.          if ((yyN = yySindex[yyState]) != 0 && (yyN += yyToken) >= 0
.              && yyN < yyTable.length && yyCheckInit.yyCheck[yyN] == yyToken) {
t            if (yydebug != null)
t              yydebug.shift(yyState, yyTable[yyN], yyErrorFlag-1);
.            yyState = yyTable[yyN];		// shift to yyN
.            yyVal = yyLex.value();
.            yyToken = -1;
.            if (yyErrorFlag > 0) -- yyErrorFlag;
.            continue yyLoop;
.          }
.          if ((yyN = yyRindex[yyState]) != 0 && (yyN += yyToken) >= 0
.              && yyN < yyTable.length && yyCheckInit.yyCheck[yyN] == yyToken)
.            yyN = yyTable[yyN];			// reduce (yyN)
.          else
.            switch (yyErrorFlag) {
.  
.            case 0:
.              yyErrorString=yyerror("syntax error", yyExpecting(yyState));
t              if (yydebug != null) yydebug.error("syntax error");
.  
.            case 1: case 2:
.              yyErrorFlag = 3;
.              do {
.                if ((yyN = yySindex[yyStates[yyTop]]) != 0
.                    && (yyN += yyErrorCode) >= 0 && yyN < yyTable.length
.                    && yyCheckInit.yyCheck[yyN] == yyErrorCode) {
t                  if (yydebug != null)
t                    yydebug.shift(yyStates[yyTop], yyTable[yyN], 3);
.                  yyState = yyTable[yyN];
.                  yyVal = yyLex.value();
.                  continue yyLoop;
.                }
t                if (yydebug != null) yydebug.pop(yyStates[yyTop]);
.              } while (-- yyTop >= 0);
t              if (yydebug != null) yydebug.reject();
.              throw new yyException(yyErrorString, yyScanner.token);
.  
.            case 3:
.              if (yyToken == 0) {
t                if (yydebug != null) yydebug.reject();
.                throw new yyException(yyErrorString+"at end-of-file", yyScanner.token);
.              }
t              if (yydebug != null)
t                yydebug.discard(yyState, yyToken, yyname(yyToken),
t  							yyLex.value());
.              yyToken = -1;
.              continue yyDiscarded;		// leave stack alone
.            }
.        }
.        int yyV = yyTop + 1-yyLen[yyN];
t        if (yydebug != null)
t          yydebug.reduce(yyState, yyStates[yyV-1], yyN, yyRule[yyN], yyLen[yyN]);
.        yyVal = yyDefault(yyV > yyTop ? null : yyVals[yyV]);
.        switch (yyN) {

 actions		## code from the actions within the grammar

.        }
.        yyTop -= yyLen[yyN];
.        yyState = yyStates[yyTop];
.        int yyM = yyLhs[yyN];
.        if (yyState == 0 && yyM == 0) {
t          if (yydebug != null) yydebug.shift(0, yyFinal);
.          yyState = yyFinal;
.          if (yyToken < 0) {
.            yyToken = yyLex.advance() ? yyLex.token() : 0;
t            if (yydebug != null)
t               yydebug.lex(yyState, yyToken,yyname(yyToken), yyLex.value());
.          }
.          if (yyToken == 0) {
t            if (yydebug != null) yydebug.accept(yyVal);
.            return yyVal;
.          }
.          continue yyLoop;
.        }
.        if ((yyN = yyGindex[yyM]) != 0 && (yyN += yyState) >= 0
.            && yyN < yyTable.length && yyCheckInit.yyCheck[yyN] == yyState)
.          yyState = yyTable[yyN];
.        else
.          yyState = yyDgoto[yyM];
t        if (yydebug != null) yydebug.shift(yyStates[yyTop], yyState);
.	 continue yyLoop;
.      }
.    }
.  }
.
 tables			## tables for rules, default reduction, and action calls
.
 epilog			## text following second %%