mcs/class/System.XML/System.Xml.Query/skeleton-2.0.cs

   1 #       jay skeleton
   2
   3 #       character in column 1 determines outcome...
   4 #               # is a comment
   5 #               . is copied
   6 #               t is copied as //t if -t is set
   7 #       other lines are interpreted to call jay procedures
   8
   9 .// created by jay 0.7 (c) 1998 Axel.Schreiner@informatik.uni-osnabrueck.de
  10 .
  11 .#if NET_2_0
  12 .
  13  prolog         ## %{ ... %} prior to the first %%
  14
  15 .
  16 .  /** error output stream.
  17 .      It should be changeable.
  18 .    */
  19 .  internal System.IO.TextWriter ErrorOutput = System.Console.Out;
  20 .
  21 .  /** simplified error message.
  22 .      @see <a href="#yyerror(java.lang.String, java.lang.String[])">yyerror</a>
  23 .    */
  24 .  internal void yyerror (string message) {
  25 .    yyerror(message, null);
  26 .  }
  27 .
  28 .  /** (syntax) error message.
  29 .      Can be overwritten to control message format.
  30 .      @param message text to be displayed.
  31 .      @param expected vector of acceptable tokens, if available.
  32 .    */
  33 .  internal void yyerror (string message, string[] expected) {
  34 .    if ((expected != null) && (expected.Length  > 0)) {
  35 .      ErrorOutput.Write (message+", expecting");
  36 .      for (int n = 0; n < expected.Length; ++ n)
  37 .        ErrorOutput.Write (" "+expected[n]);
  38 .        ErrorOutput.WriteLine ();
  39 .    } else
  40 .      ErrorOutput.WriteLine (message);
  41 .  }
  42 .
  43 .  /** debugging support, requires the package jay.yydebug.
  44 .      Set to null to suppress debugging messages.
  45 .    */
  46 t  internal yydebug.yyDebug debug;
  47 .
  48  debug                  ## tables for debugging support
  49 .
  50 .  /** index-checked interface to yyNames[].
  51 .      @param token single character or %token value.
  52 .      @return token name or [illegal] or [unknown].
  53 .    */
  54 t  internal static string yyname (int token) {
  55 t    if ((token < 0) || (token > yyNames.Length)) return "[illegal]";
  56 t    string name;
  57 t    if ((name = yyNames[token]) != null) return name;
  58 t    return "[unknown]";
  59 t  }
  60 .
  61 .  /** computes list of expected tokens on error by tracing the tables.
  62 .      @param state for which to compute the list.
  63 .      @return list of token names.
  64 .    */
  65 .  internal string[] yyExpecting (int state) {
  66 .    int token, n, len = 0;
  67 .    bool[] ok = new bool[yyNames.Length];
  68 .
  69 .    if ((n = yySindex[state]) != 0)
  70 .      for (token = n < 0 ? -n : 0;
  71 .           (token < yyNames.Length) && (n+token < yyTable.Length); ++ token)
  72 .        if (yyCheck[n+token] == token && !ok[token] && yyNames[token] != null) {
  73 .          ++ len;
  74 .          ok[token] = true;
  75 .        }
  76 .    if ((n = yyRindex[state]) != 0)
  77 .      for (token = n < 0 ? -n : 0;
  78 .           (token < yyNames.Length) && (n+token < yyTable.Length); ++ token)
  79 .        if (yyCheck[n+token] == token && !ok[token] && yyNames[token] != null) {
  80 .          ++ len;
  81 .          ok[token] = true;
  82 .        }
  83 .
  84 .    string [] result = new string[len];
  85 .    for (n = token = 0; n < len;  ++ token)
  86 .      if (ok[token]) result[n++] = yyNames[token];
  87 .    return result;
  88 .  }
  89 .
  90 .  /** the generated parser, with debugging messages.
  91 .      Maintains a state and a value stack, currently with fixed maximum size.
  92 .      @param yyLex scanner.
  93 .      @param yydebug debug message writer implementing yyDebug, or null.
  94 .      @return result of the last reduction, if any.
  95 .      @throws yyException on irrecoverable parse error.
  96 .    */
  97 .  internal Object yyparse (yyParser.yyInput yyLex, Object yyd)
  98 .                                {
  99 t    this.debug = (yydebug.yyDebug)yyd;
 100 .    return yyparse(yyLex);
 101 .  }
 102 .
 103 .  /** initial size and increment of the state/value stack [default 256].
 104 .      This is not final so that it can be overwritten outside of invocations
 105 .      of yyparse().
 106 .    */
 107 .  internal int yyMax;
 108 .
 109 .  /** executed at the beginning of a reduce action.
 110 .      Used as $$ = yyDefault($1), prior to the user-specified action, if any.
 111 .      Can be overwritten to provide deep copy, etc.
 112 .      @param first value for $1, or null.
 113 .      @return first.
 114 .    */
 115 .  internal Object yyDefault (Object first) {
 116 .    return first;
 117 .  }
 118 .
 119 .  /** the generated parser.
 120 .      Maintains a state and a value stack, currently with fixed maximum size.
 121 .      @param yyLex scanner.
 122 .      @return result of the last reduction, if any.
 123 .      @throws yyException on irrecoverable parse error.
 124 .    */
 125 .  internal Object yyparse (yyParser.yyInput yyLex)
 126 .                               {
 127 .    if (yyMax <= 0) yyMax = 256;                       // initial size
 128 .    int yyState = 0;                                   // state stack ptr
 129 .    int [] yyStates = new int[yyMax];                  // state stack
 130 .    Object yyVal = null;                               // value stack ptr
 131 .    Object [] yyVals = new Object[yyMax];              // value stack
 132 .    int yyToken = -1;                                  // current input
 133 .    int yyErrorFlag = 0;                               // #tks to shift
 134 .
 135  local          ## %{ ... %} after the first %%
 136
 137 .    int yyTop = 0;
 138 .    goto skip;
 139 .    yyLoop:
 140 .    yyTop++;
 141 .    skip:
 142 .    for (;; ++ yyTop) {
 143 .      if (yyTop >= yyStates.Length) {                  // dynamically increase
 144 .        int[] i = new int[yyStates.Length+yyMax];
 145 .        yyStates.CopyTo (i, 0);
 146 .        yyStates = i;
 147 .        Object[] o = new Object[yyVals.Length+yyMax];
 148 .        yyVals.CopyTo (o, 0);
 149 .        yyVals = o;
 150 .      }
 151 .      yyStates[yyTop] = yyState;
 152 .      yyVals[yyTop] = yyVal;
 153 t      if (debug != null) debug.push(yyState, yyVal);
 154 .
 155 .      yyDiscarded: for (;;) {  // discarding a token does not change stack
 156 .        int yyN;
 157 .        if ((yyN = yyDefRed[yyState]) == 0) {  // else [default] reduce (yyN)
 158 .          if (yyToken < 0) {
 159 .            yyToken = yyLex.advance() ? yyLex.token() : 0;
 160
 161 t            if (debug != null)
 162 t              debug.lex(yyState, yyToken, yyname(yyToken), yyLex.value());
 163 .          }
 164 .          if ((yyN = yySindex[yyState]) != 0 && ((yyN += yyToken) >= 0)
 165 .              && (yyN < yyTable.Length) && (yyCheck[yyN] == yyToken)) {
 166 t            if (debug != null)
 167 t              debug.shift(yyState, yyTable[yyN], yyErrorFlag-1);
 168 .            yyState = yyTable[yyN];            // shift to yyN
 169 .            yyVal = yyLex.value();
 170 .            yyToken = -1;
 171 .            if (yyErrorFlag > 0) -- yyErrorFlag;
 172 .            goto yyLoop;
 173 .          }
 174 .          if ((yyN = yyRindex[yyState]) != 0 && (yyN += yyToken) >= 0
 175 .              && yyN < yyTable.Length && yyCheck[yyN] == yyToken)
 176 .            yyN = yyTable[yyN];                        // reduce (yyN)
 177 .          else
 178 .            switch (yyErrorFlag) {
 179 .
 180 .            case 0:
 181 .              yyerror(String.Format ("syntax error, got token `{0}'", yyname (yyToken)), yyExpecting(yyState));
 182 t              if (debug != null) debug.error("syntax error");
 183 .              goto case 1;
 184 .            case 1: case 2:
 185 .              yyErrorFlag = 3;
 186 .              do {
 187 .                if ((yyN = yySindex[yyStates[yyTop]]) != 0
 188 .                    && (yyN += Token.yyErrorCode) >= 0 && yyN < yyTable.Length
 189 .                    && yyCheck[yyN] == Token.yyErrorCode) {
 190 t                  if (debug != null)
 191 t                    debug.shift(yyStates[yyTop], yyTable[yyN], 3);
 192 .                  yyState = yyTable[yyN];
 193 .                  yyVal = yyLex.value();
 194 .                  goto yyLoop;
 195 .                }
 196 t                if (debug != null) debug.pop(yyStates[yyTop]);
 197 .              } while (-- yyTop >= 0);
 198 t              if (debug != null) debug.reject();
 199 .              throw new yyParser.yyException("irrecoverable syntax error");
 200 .
 201 .            case 3:
 202 .              if (yyToken == 0) {
 203 t                if (debug != null) debug.reject();
 204 .                throw new yyParser.yyException("irrecoverable syntax error at end-of-file");
 205 .              }
 206 t              if (debug != null)
 207 t                debug.discard(yyState, yyToken, yyname(yyToken),
 208 t                                                       yyLex.value());
 209 .              yyToken = -1;
 210 .              goto yyDiscarded;                // leave stack alone
 211 .            }
 212 .        }
 213 .        int yyV = yyTop + 1-yyLen[yyN];
 214 t        if (debug != null)
 215 t          debug.reduce(yyState, yyStates[yyV-1], yyN, yyRule[yyN], yyLen[yyN]);
 216 .        yyVal = yyDefault(yyV > yyTop ? null : yyVals[yyV]);
 217 .        switch (yyN) {
 218
 219  actions                ## code from the actions within the grammar
 220
 221 .        }
 222 .        yyTop -= yyLen[yyN];
 223 .        yyState = yyStates[yyTop];
 224 .        int yyM = yyLhs[yyN];
 225 .        if (yyState == 0 && yyM == 0) {
 226 t          if (debug != null) debug.shift(0, yyFinal);
 227 .          yyState = yyFinal;
 228 .          if (yyToken < 0) {
 229 .            yyToken = yyLex.advance() ? yyLex.token() : 0;
 230
 231 t            if (debug != null)
 232 t               debug.lex(yyState, yyToken,yyname(yyToken), yyLex.value());
 233 .          }
 234 .          if (yyToken == 0) {
 235 t            if (debug != null) debug.accept(yyVal);
 236 .            return yyVal;
 237 .          }
 238 .          goto yyLoop;
 239 .        }
 240 .        if (((yyN = yyGindex[yyM]) != 0) && ((yyN += yyState) >= 0)
 241 .            && (yyN < yyTable.Length) && (yyCheck[yyN] == yyState))
 242 .          yyState = yyTable[yyN];
 243 .        else
 244 .          yyState = yyDgoto[yyM];
 245 t        if (debug != null) debug.shift(yyStates[yyTop], yyState);
 246 .        goto yyLoop;
 247 .      }
 248 .    }
 249 .  }
 250 .
 251  tables                 ## tables for rules, default reduction, and action calls
 252 .
 253  epilog                 ## text following second %%
 254 .namespace yydebug {
 255 .        using System;
 256 .        internal interface yyDebug {
 257 .                void push (int state, Object value);
 258 .                void lex (int state, int token, string name, Object value);
 259 .                void shift (int from, int to, int errorFlag);
 260 .                void pop (int state);
 261 .                void discard (int state, int token, string name, Object value);
 262 .                void reduce (int from, int to, int rule, string text, int len);
 263 .                void shift (int from, int to);
 264 .                void accept (Object value);
 265 .                void error (string message);
 266 .                void reject ();
 267 .        }
 268 .
 269 .        class yyDebugSimple : yyDebug {
 270 .                void println (string s){
 271 .                        Console.Error.WriteLine (s);
 272 .                }
 273 .
 274 .                public void push (int state, Object value) {
 275 .                        println ("push\tstate "+state+"\tvalue "+value);
 276 .                }
 277 .
 278 .                public void lex (int state, int token, string name, Object value) {
 279 .                        println("lex\tstate "+state+"\treading "+name+"\tvalue "+value);
 280 .                }
 281 .
 282 .                public void shift (int from, int to, int errorFlag) {
 283 .                        switch (errorFlag) {
 284 .                        default:                               // normally
 285 .                                println("shift\tfrom state "+from+" to "+to);
 286 .                                break;
 287 .                        case 0: case 1: case 2:                // in error recovery
 288 .                                println("shift\tfrom state "+from+" to "+to
 289 .                                            +"\t"+errorFlag+" left to recover");
 290 .                                break;
 291 .                        case 3:                                // normally
 292 .                                println("shift\tfrom state "+from+" to "+to+"\ton error");
 293 .                                break;
 294 .                        }
 295 .                }
 296 .
 297 .                public void pop (int state) {
 298 .                        println("pop\tstate "+state+"\ton error");
 299 .                }
 300 .
 301 .                public void discard (int state, int token, string name, Object value) {
 302 .                        println("discard\tstate "+state+"\ttoken "+name+"\tvalue "+value);
 303 .                }
 304 .
 305 .                public void reduce (int from, int to, int rule, string text, int len) {
 306 .                        println("reduce\tstate "+from+"\tuncover "+to
 307 .                                    +"\trule ("+rule+") "+text);
 308 .                }
 309 .
 310 .                public void shift (int from, int to) {
 311 .                        println("goto\tfrom state "+from+" to "+to);
 312 .                }
 313 .
 314 .                public void accept (Object value) {
 315 .                        println("accept\tvalue "+value);
 316 .                }
 317 .
 318 .                public void error (string message) {
 319 .                        println("error\t"+message);
 320 .                }
 321 .
 322 .                public void reject () {
 323 .                        println("reject");
 324 .                }
 325 .
 326 .        }
 327 .}
 328 .// %token constants
 329 . class Token {
 330  tokens public const int
 331 . }
 332 . namespace yyParser {
 333 .  using System;
 334 .  /** thrown for irrecoverable syntax errors and stack overflow.
 335 .    */
 336 .  internal class yyException : System.Exception {
 337 .    public yyException (string message) : base (message) {
 338 .    }
 339 .  }
 340 .
 341 .  /** must be implemented by a scanner object to supply input to the parser.
 342 .    */
 343 .  internal interface yyInput {
 344 .    /** move on to next token.
 345 .        @return false if positioned beyond tokens.
 346 .        @throws IOException on input error.
 347 .      */
 348 .    bool advance (); // throws java.io.IOException;
 349 .    /** classifies current token.
 350 .        Should not be called if advance() returned false.
 351 .        @return current %token or single character.
 352 .      */
 353 .    int token ();
 354 .    /** associated with current token.
 355 .        Should not be called if advance() returned false.
 356 .        @return value for token().
 357 .      */
 358 .    Object value ();
 359 .  }
 360 . }
 361 .} // close outermost namespace, that MUST HAVE BEEN opened in the prolog
 362 .
 363 .#endif
 364