3 # character in column 1 determines outcome...
6 # t is copied as //t if -t is set
7 # other lines are interpreted to call jay procedures
9 .// created by jay 0.7 (c) 1998 Axel.Schreiner@informatik.uni-osnabrueck.de
11 prolog
## %{ ... %} prior to the first %%
14 . /** error output stream.
15 . It should be changeable.
17 . public System
.IO
.TextWriter ErrorOutput
= System
.Console
.Out
;
19 . /** simplified error message.
20 . @see <a href="#yyerror(java.lang.String, java.lang.String[])">yyerror</a>
22 . public void yyerror (string message
) {
23 . yyerror(message
, null);
27 . public int eof_token
;
29 . /** (syntax) error message.
30 . Can be overwritten to control message format.
31 . @param message text to be displayed.
32 . @param expected vector of acceptable tokens, if available.
34 . public void yyerror (string message
, string[] expected
) {
35 . if ((yacc_verbose_flag
> 0) && (expected
!= null) && (expected
.Length
> 0)) {
36 . ErrorOutput
.Write (message
+", expecting");
37 . for (int n
= 0; n
< expected
.Length
; ++ n
)
38 . ErrorOutput
.Write (" "+expected
[n
]);
39 . ErrorOutput
.WriteLine ();
41 . ErrorOutput
.WriteLine (message
);
44 . /** debugging support, requires the package jay.yydebug.
45 . Set to null to suppress debugging messages.
47 t
internal yydebug
.yyDebug debug
;
49 debug
## tables for debugging support
51 . /** index-checked interface to yyNames[].
52 . @param token single character or %token value.
53 . @return token name or [illegal] or [unknown].
55 t
public static string yyname (int token
) {
56 t
if ((token
< 0) || (token
> yyNames
.Length
)) return "[illegal]";
58 t
if ((name
= yyNames
[token
]) != null) return name
;
62 . int yyExpectingState
;
63 . /** computes list of expected tokens on error by tracing the tables.
64 . @param state for which to compute the list.
65 . @return list of token names.
67 . protected int [] yyExpectingTokens (int state
){
68 . int token
, n
, len
= 0;
69 . bool[] ok
= new bool[yyNames
.Length
];
70 . if ((n
= yySindex
[state
]) != 0)
71 . for (token
= n
< 0 ? -n
: 0;
72 . (token
< yyNames
.Length
) && (n
+token
< yyTable
.Length
); ++ token
)
73 . if (yyCheck
[n
+token
] == token
&& !ok
[token
] && yyNames
[token
] != null) {
77 . if ((n
= yyRindex
[state
]) != 0)
78 . for (token
= n
< 0 ? -n
: 0;
79 . (token
< yyNames
.Length
) && (n
+token
< yyTable
.Length
); ++ token
)
80 . if (yyCheck
[n
+token
] == token
&& !ok
[token
] && yyNames
[token
] != null) {
84 . int [] result
= new int [len
];
85 . for (n
= token
= 0; n
< len
; ++ token
)
86 . if (ok
[token
]) result
[n
++] = token
;
89 . protected string[] yyExpecting (int state
) {
90 . int [] tokens
= yyExpectingTokens (state
);
91 . string [] result
= new string[tokens
.Length
];
92 . for (int n
= 0; n
< tokens
.Length
; n
++)
93 . result
[n
++] = yyNames
[tokens
[n
]];
97 . /** the generated parser, with debugging messages.
98 . Maintains a state and a value stack, currently with fixed maximum size.
99 . @param yyLex scanner.
100 . @param yydebug debug message writer implementing yyDebug, or null.
101 . @return result of the last reduction, if any.
102 . @throws yyException on irrecoverable parse error.
104 . internal Object
yyparse (yyParser
.yyInput yyLex
, Object yyd
)
106 t
this.debug
= (yydebug
.yyDebug
)yyd
;
107 . return yyparse(yyLex
);
110 . /** initial size and increment of the state/value stack [default 256].
111 . This is not final so that it can be overwritten outside of invocations
114 . protected int yyMax
;
116 . /** executed at the beginning of a reduce action.
117 . Used as $$ = yyDefault($1), prior to the user-specified action, if any.
118 . Can be overwritten to provide deep copy, etc.
119 . @param first value for $1, or null.
122 . protected Object
yyDefault (Object first
) {
126 . /** the generated parser.
127 . Maintains a state and a value stack, currently with fixed maximum size.
128 . @param yyLex scanner.
129 . @return result of the last reduction, if any.
130 . @throws yyException on irrecoverable parse error.
132 . internal Object
yyparse (yyParser
.yyInput yyLex
)
134 . if (yyMax
<= 0) yyMax
= 256; // initial size
135 . int yyState
= 0; // state stack ptr
136 . int [] yyStates
= new int[yyMax
]; // state stack
137 . Object yyVal
= null; // value stack ptr
138 . Object
[] yyVals
= new Object
[yyMax
]; // value stack
139 . int yyToken
= -1; // current input
140 . int yyErrorFlag
= 0; // #tks to shift
142 local
## %{ ... %} after the first %%
144 . /*yyLoop:*/ for (int yyTop
= 0;; ++ yyTop
) {
145 . if (yyTop
>= yyStates
.Length
) { // dynamically increase
146 . int[] i
= new int[yyStates
.Length
+yyMax
];
147 . yyStates
.CopyTo (i
, 0);
149 . Object
[] o
= new Object
[yyVals
.Length
+yyMax
];
150 . yyVals
.CopyTo (o
, 0);
153 . yyStates
[yyTop
] = yyState
;
154 . yyVals
[yyTop
] = yyVal
;
155 t
if (debug
!= null) debug
.push(yyState
, yyVal
);
157 . /*yyDiscarded:*/ for (;;) { // discarding a token does not change stack
159 . if ((yyN
= yyDefRed
[yyState
]) == 0) { // else [default] reduce (yyN)
161 . yyToken
= yyLex
.advance() ? yyLex
.token() : 0;
164 t debug
.lex(yyState
, yyToken
, yyname(yyToken
), yyLex
.value());
166 . if ((yyN
= yySindex
[yyState
]) != 0 && ((yyN
+= yyToken
) >= 0)
167 . && (yyN
< yyTable
.Length
) && (yyCheck
[yyN
] == yyToken
)) {
169 t debug
.shift(yyState
, yyTable
[yyN
], yyErrorFlag
-1);
170 . yyState
= yyTable
[yyN
]; // shift to yyN
171 . yyVal
= yyLex
.value();
173 . if (yyErrorFlag
> 0) -- yyErrorFlag
;
174 . goto continue_yyLoop
;
176 . if ((yyN
= yyRindex
[yyState
]) != 0 && (yyN
+= yyToken
) >= 0
177 . && yyN
< yyTable
.Length
&& yyCheck
[yyN
] == yyToken
)
178 . yyN
= yyTable
[yyN
]; // reduce (yyN)
180 . switch (yyErrorFlag
) {
183 . yyExpectingState
= yyState
;
184 . // yyerror(String.Format ("syntax error, got token `{0}'", yyname (yyToken)), yyExpecting(yyState));
185 t
if (debug
!= null) debug
.error("syntax error");
186 . if (yyToken
== 0 /*eof*/ || yyToken
== eof_token
) throw new yyParser
.yyUnexpectedEof ();
191 . if ((yyN
= yySindex
[yyStates
[yyTop
]]) != 0
192 . && (yyN
+= Token
.yyErrorCode
) >= 0 && yyN
< yyTable
.Length
193 . && yyCheck
[yyN
] == Token
.yyErrorCode
) {
195 t debug
.shift(yyStates
[yyTop
], yyTable
[yyN
], 3);
196 . yyState
= yyTable
[yyN
];
197 . yyVal
= yyLex
.value();
198 . goto continue_yyLoop
;
200 t
if (debug
!= null) debug
.pop(yyStates
[yyTop
]);
201 . } while (-- yyTop
>= 0);
202 t
if (debug
!= null) debug
.reject();
203 . throw new yyParser
.yyException("irrecoverable syntax error");
206 . if (yyToken
== 0) {
207 t
if (debug
!= null) debug
.reject();
208 . throw new yyParser
.yyException("irrecoverable syntax error at end-of-file");
211 t debug
.discard(yyState
, yyToken
, yyname(yyToken
),
214 . goto continue_yyDiscarded
; // leave stack alone
217 . int yyV
= yyTop
+ 1-yyLen
[yyN
];
219 t debug
.reduce(yyState
, yyStates
[yyV
-1], yyN
, YYRules
.getRule (yyN
), yyLen
[yyN
]);
220 . yyVal
= yyDefault(yyV
> yyTop
? null : yyVals
[yyV
]);
223 actions
## code from the actions within the grammar
226 . yyTop
-= yyLen
[yyN
];
227 . yyState
= yyStates
[yyTop
];
228 . int yyM
= yyLhs
[yyN
];
229 . if (yyState
== 0 && yyM
== 0) {
230 t
if (debug
!= null) debug
.shift(0, yyFinal
);
233 . yyToken
= yyLex
.advance() ? yyLex
.token() : 0;
236 t debug
.lex(yyState
, yyToken
,yyname(yyToken
), yyLex
.value());
238 . if (yyToken
== 0) {
239 t
if (debug
!= null) debug
.accept(yyVal
);
242 . goto continue_yyLoop
;
244 . if (((yyN
= yyGindex
[yyM
]) != 0) && ((yyN
+= yyState
) >= 0)
245 . && (yyN
< yyTable
.Length
) && (yyCheck
[yyN
] == yyState
))
246 . yyState
= yyTable
[yyN
];
248 . yyState
= yyDgoto
[yyM
];
249 t
if (debug
!= null) debug
.shift(yyStates
[yyTop
], yyState
);
250 . goto continue_yyLoop
;
251 . continue_yyDiscarded
: continue; // implements the named-loop continue: 'continue yyDiscarded'
253 . continue_yyLoop
: continue; // implements the named-loop continue: 'continue yyLoop'
257 tables
## tables for rules, default reduction, and action calls
259 epilog
## text following second %%
262 . internal interface yyDebug
{
263 . void push (int state
, Object
value);
264 . void lex (int state
, int token
, string name
, Object
value);
265 . void shift (int from, int to
, int errorFlag
);
266 . void pop (int state
);
267 . void discard (int state
, int token
, string name
, Object
value);
268 . void reduce (int from, int to
, int rule
, string text
, int len
);
269 . void shift (int from, int to
);
270 . void accept (Object
value);
271 . void error (string message
);
275 . class yyDebugSimple
: yyDebug
{
276 . void println (string s
){
277 . Console
.Error
.WriteLine (s
);
280 . public void push (int state
, Object
value) {
281 . println ("push\tstate "+state
+"\tvalue "+value);
284 . public void lex (int state
, int token
, string name
, Object
value) {
285 . println("lex\tstate "+state
+"\treading "+name
+"\tvalue "+value);
288 . public void shift (int from, int to
, int errorFlag
) {
289 . switch (errorFlag
) {
290 . default: // normally
291 . println("shift\tfrom state "+from+" to "+to
);
293 . case 0: case 1: case 2: // in error recovery
294 . println("shift\tfrom state "+from+" to "+to
295 . +"\t"+errorFlag
+" left to recover");
297 . case 3: // normally
298 . println("shift\tfrom state "+from+" to "+to
+"\ton error");
303 . public void pop (int state
) {
304 . println("pop\tstate "+state
+"\ton error");
307 . public void discard (int state
, int token
, string name
, Object
value) {
308 . println("discard\tstate "+state
+"\ttoken "+name
+"\tvalue "+value);
311 . public void reduce (int from, int to
, int rule
, string text
, int len
) {
312 . println("reduce\tstate "+from+"\tuncover "+to
313 . +"\trule ("+rule
+") "+text
);
316 . public void shift (int from, int to
) {
317 . println("goto\tfrom state "+from+" to "+to
);
320 . public void accept (Object
value) {
321 . println("accept\tvalue "+value);
324 . public void error (string message
) {
325 . println("error\t"+message
);
328 . public void reject () {
336 tokens
public const int
338 . namespace yyParser
{
340 . /** thrown for irrecoverable syntax errors and stack overflow.
342 . internal class yyException
: System
.Exception
{
343 . public yyException (string message
) : base (message
) {
346 . internal class yyUnexpectedEof
: yyException
{
347 . public yyUnexpectedEof (string message
) : base (message
) {
349 . public yyUnexpectedEof () : base ("") {
353 . /** must be implemented by a scanner object to supply input to the parser.
355 . internal interface yyInput
{
356 . /** move on to next token.
357 . @return false if positioned beyond tokens.
358 . @throws IOException on input error.
360 . bool advance (); // throws java.io.IOException;
361 . /** classifies current token.
362 . Should not be called if advance() returned false.
363 . @return current %token or single character.
366 . /** associated with current token.
367 . Should not be called if advance() returned false.
368 . @return value for token().
373 .} // close outermost namespace, that MUST HAVE BEEN opened in the prolog