[inseparable changes from patch from perl5.003_11 to perl5.003_12]
[p5sagit/p5-mst-13.2.git] / perly.y
1 /*    perly.y
2  *
3  *    Copyright (c) 1991-1994, Larry Wall
4  *
5  *    You may distribute under the terms of either the GNU General Public
6  *    License or the Artistic License, as specified in the README file.
7  *
8  */
9
10 /*
11  * 'I see,' laughed Strider.  'I look foul and feel fair.  Is that it?
12  * All that is gold does not glitter, not all those that wander are lost.'
13  */
14
15 %{
16 #include "EXTERN.h"
17 #include "perl.h"
18
19 static void
20 dep()
21 {
22     deprecate("\"do\" to call subroutines");
23 }
24
25 %}
26
27 %start prog
28
29 %union {
30     I32 ival;
31     char *pval;
32     OP *opval;
33     GV *gvval;
34 }
35
36 %token <ival> '{' ')'
37
38 %token <opval> WORD METHOD FUNCMETH THING PMFUNC PRIVATEREF
39 %token <opval> FUNC0SUB UNIOPSUB LSTOPSUB
40 %token <pval> LABEL
41 %token <ival> FORMAT SUB ANONSUB PACKAGE USE
42 %token <ival> WHILE UNTIL IF UNLESS ELSE ELSIF CONTINUE FOR
43 %token <ival> LOOPEX DOTDOT
44 %token <ival> FUNC0 FUNC1 FUNC UNIOP LSTOP
45 %token <ival> RELOP EQOP MULOP ADDOP
46 %token <ival> DOLSHARP DO HASHBRACK NOAMP
47 %token LOCAL MY
48
49 %type <ival> prog decl local format startsub remember mremember '&'
50 %type <opval> block mblock lineseq line loop cond else
51 %type <opval> expr term scalar ary hsh arylen star amper sideff
52 %type <opval> argexpr nexpr texpr iexpr mexpr mnexpr mtexpr miexpr
53 %type <opval> listexpr listexprcom indirob
54 %type <opval> listop method proto cont my_scalar
55 %type <pval> label
56
57 %left <ival> OROP
58 %left ANDOP
59 %right NOTOP
60 %nonassoc LSTOP LSTOPSUB
61 %left ','
62 %right <ival> ASSIGNOP
63 %right '?' ':'
64 %nonassoc DOTDOT
65 %left OROR
66 %left ANDAND
67 %left <ival> BITOROP
68 %left <ival> BITANDOP
69 %nonassoc EQOP
70 %nonassoc RELOP
71 %nonassoc UNIOP UNIOPSUB
72 %left <ival> SHIFTOP
73 %left ADDOP
74 %left MULOP
75 %left <ival> MATCHOP
76 %right '!' '~' UMINUS REFGEN
77 %right <ival> POWOP
78 %nonassoc PREINC PREDEC POSTINC POSTDEC
79 %left ARROW
80 %left '('
81
82 %% /* RULES */
83
84 prog    :       /* NULL */
85                 {
86 #if defined(YYDEBUG) && defined(DEBUGGING)
87                     yydebug = (debug & 1);
88 #endif
89                     expect = XSTATE;
90                 }
91         /*CONTINUED*/   lineseq
92                         { newPROG($2); }
93         ;
94
95 block   :       '{' remember lineseq '}'
96                         { if (copline > (line_t)$1)
97                               copline = $1;
98                           $$ = block_end($2, $3); }
99         ;
100
101 remember:       /* NULL */      /* start a full lexical scope */
102                         { $$ = block_start(TRUE); }
103         ;
104
105 mblock  :       '{' mremember lineseq '}'
106                         { if (copline > (line_t)$1)
107                               copline = $1;
108                           $$ = block_end($2, $3); }
109         ;
110
111 mremember:      /* NULL */      /* start a partial lexical scope */
112                         { $$ = block_start(FALSE); }
113         ;
114
115 lineseq :       /* NULL */
116                         { $$ = Nullop; }
117         |       lineseq decl
118                         { $$ = $1; }
119         |       lineseq line
120                         {   $$ = append_list(OP_LINESEQ,
121                                 (LISTOP*)$1, (LISTOP*)$2);
122                             pad_reset_pending = TRUE;
123                             if ($1 && $2) hints |= HINT_BLOCK_SCOPE; }
124         ;
125
126 line    :       label cond
127                         { $$ = newSTATEOP(0, $1, $2); }
128         |       loop    /* loops add their own labels */
129         |       label ';'
130                         { if ($1 != Nullch) {
131                               $$ = newSTATEOP(0, $1, newOP(OP_NULL, 0));
132                             }
133                             else {
134                               $$ = Nullop;
135                               copline = NOLINE;
136                             }
137                             expect = XSTATE; }
138         |       label sideff ';'
139                         { $$ = newSTATEOP(0, $1, $2);
140                           expect = XSTATE; }
141         ;
142
143 sideff  :       error
144                         { $$ = Nullop; }
145         |       expr
146                         { $$ = $1; }
147         |       expr IF expr
148                         { $$ = newLOGOP(OP_AND, 0, $3, $1); }
149         |       expr UNLESS expr
150                         { $$ = newLOGOP(OP_OR, 0, $3, $1); }
151         |       expr WHILE expr
152                         { $$ = newLOOPOP(OPf_PARENS, 1, scalar($3), $1); }
153         |       expr UNTIL iexpr
154                         { $$ = newLOOPOP(OPf_PARENS, 1, $3, $1);}
155         ;
156
157 else    :       /* NULL */
158                         { $$ = Nullop; }
159         |       ELSE mblock
160                         { $$ = scope($2); }
161         |       ELSIF '(' mexpr ')' mblock else
162                         { copline = $1;
163                             $$ = newSTATEOP(0, Nullch,
164                                    newCONDOP(0, $3, scope($5), $6));
165                             hints |= HINT_BLOCK_SCOPE; }
166         ;
167
168 cond    :       IF '(' remember mexpr ')' mblock else
169                         { copline = $1;
170                             $$ = block_end($3,
171                                    newCONDOP(0, $4, scope($6), $7)); }
172         |       UNLESS '(' remember miexpr ')' mblock else
173                         { copline = $1;
174                             $$ = block_end($3,
175                                    newCONDOP(0, $4, scope($6), $7)); }
176         |       IF block block else
177                         { copline = $1;
178                             deprecate("if BLOCK BLOCK");
179                             $$ = newCONDOP(0, scope($2), scope($3), $4); }
180         |       UNLESS block block else
181                         { copline = $1;
182                             deprecate("unless BLOCK BLOCK");
183                             $$ = newCONDOP(0, invert(scalar(scope($2))),
184                                                 scope($3), $4); }
185         ;
186
187 cont    :       /* NULL */
188                         { $$ = Nullop; }
189         |       CONTINUE block
190                         { $$ = scope($2); }
191         ;
192
193 loop    :       label WHILE '(' remember mtexpr ')' mblock cont
194                         { copline = $2;
195                             $$ = block_end($4,
196                                    newSTATEOP(0, $1,
197                                      newWHILEOP(0, 1, (LOOP*)Nullop,
198                                                 $5, $7, $8))); }
199         |       label UNTIL '(' remember miexpr ')' mblock cont
200                         { copline = $2;
201                             $$ = block_end($4,
202                                    newSTATEOP(0, $1,
203                                      newWHILEOP(0, 1, (LOOP*)Nullop,
204                                                 $5, $7, $8))); }
205         |       label WHILE block block cont
206                         { copline = $2;
207                             deprecate("while BLOCK BLOCK");
208                             $$ = newSTATEOP(0, $1,
209                                    newWHILEOP(0, 1, (LOOP*)Nullop,
210                                               scope($3), $4, $5)); }
211         |       label UNTIL block block cont
212                         { copline = $2;
213                             deprecate("until BLOCK BLOCK");
214                             $$ = newSTATEOP(0, $1,
215                                    newWHILEOP(0, 1, (LOOP*)Nullop,
216                                               invert(scalar(scope($3))),
217                                               $4, $5)); }
218         |       label FOR MY remember my_scalar '(' mexpr ')' mblock cont
219                         { $$ = block_end($4,
220                                  newFOROP(0, $1, $2, $5, $7, $9, $10)); }
221         |       label FOR scalar '(' remember mexpr ')' mblock cont
222                         { $$ = block_end($5,
223                                  newFOROP(0, $1, $2, mod($3, OP_ENTERLOOP),
224                                           $6, $8, $9)); }
225         |       label FOR '(' remember mexpr ')' mblock cont
226                         { $$ = block_end($4,
227                                  newFOROP(0, $1, $2, Nullop, $5, $7, $8)); }
228         |       label FOR '(' remember mnexpr ';' mtexpr ';' mnexpr ')' mblock
229                         /* basically fake up an initialize-while lineseq */
230                         { copline = $2;
231                             $$ = block_end($4,
232                                    append_elem(OP_LINESEQ, scalar($5),
233                                      newSTATEOP(0, $1,
234                                        newWHILEOP(0, 1, (LOOP*)Nullop,
235                                                   scalar($7),
236                                                   $11, scalar($9))))); }
237         |       label block cont  /* a block is a loop that happens once */
238                         { $$ = newSTATEOP(0,
239                                 $1, newWHILEOP(0, 1, (LOOP*)Nullop,
240                                         Nullop, $2, $3)); }
241         ;
242
243 nexpr   :       /* NULL */
244                         { $$ = Nullop; }
245         |       sideff
246         ;
247
248 texpr   :       /* NULL means true */
249                         { (void)scan_num("1"); $$ = yylval.opval; }
250         |       expr
251         ;
252
253 iexpr   :       expr
254                         { $$ = invert(scalar($1)); }
255         ;
256
257 mexpr   :       expr
258                         { $$ = $1; intro_my(); }
259         ;
260
261 mnexpr  :       nexpr
262                         { $$ = $1; intro_my(); }
263         ;
264
265 mtexpr  :       texpr
266                         { $$ = $1; intro_my(); }
267         ;
268
269 miexpr  :       iexpr
270                         { $$ = $1; intro_my(); }
271         ;
272
273 label   :       /* empty */
274                         { $$ = Nullch; }
275         |       LABEL
276         ;
277
278 decl    :       format
279                         { $$ = 0; }
280         |       subrout
281                         { $$ = 0; }
282         |       package
283                         { $$ = 0; }
284         |       use
285                         { $$ = 0; }
286         ;
287
288 format  :       FORMAT startsub WORD block
289                         { newFORM($2, $3, $4); }
290         |       FORMAT startsub block
291                         { newFORM($2, Nullop, $3); }
292         ;
293
294 subrout :       SUB startsub WORD proto block
295                         { newSUB($2, $3, $4, $5); }
296         |       SUB startsub WORD proto ';'
297                         { newSUB($2, $3, $4, Nullop); expect = XSTATE; }
298         ;
299
300 proto   :       /* NULL */
301                         { $$ = Nullop; }
302         |       THING
303         ;
304                 
305 startsub:       /* NULL */      /* start a subroutine scope */
306                         { $$ = start_subparse(); }
307         ;
308
309 package :       PACKAGE WORD ';'
310                         { package($2); }
311         |       PACKAGE ';'
312                         { package(Nullop); }
313         ;
314
315 use     :       USE startsub WORD WORD listexpr ';'
316                         { utilize($1, $2, $3, $4, $5); }
317         ;
318
319 expr    :       expr ANDOP expr
320                         { $$ = newLOGOP(OP_AND, 0, $1, $3); }
321         |       expr OROP expr
322                         { $$ = newLOGOP($2, 0, $1, $3); }
323         |       argexpr
324         ;
325
326 argexpr :       argexpr ','
327                         { $$ = $1; }
328         |       argexpr ',' term
329                         { $$ = append_elem(OP_LIST, $1, $3); }
330         |       term
331         ;
332
333 listop  :       LSTOP indirob argexpr
334                         { $$ = convert($1, OPf_STACKED,
335                                 prepend_elem(OP_LIST, newGVREF($1,$2), $3) ); }
336         |       FUNC '(' indirob expr ')'
337                         { $$ = convert($1, OPf_STACKED,
338                                 prepend_elem(OP_LIST, newGVREF($1,$3), $4) ); }
339         |       term ARROW method '(' listexprcom ')'
340                         { $$ = convert(OP_ENTERSUB, OPf_STACKED,
341                                 append_elem(OP_LIST,
342                                     prepend_elem(OP_LIST, scalar($1), $5),
343                                     newUNOP(OP_METHOD, 0, $3))); }
344         |       METHOD indirob listexpr
345                         { $$ = convert(OP_ENTERSUB, OPf_STACKED,
346                                 append_elem(OP_LIST,
347                                     prepend_elem(OP_LIST, $2, $3),
348                                     newUNOP(OP_METHOD, 0, $1))); }
349         |       FUNCMETH indirob '(' listexprcom ')'
350                         { $$ = convert(OP_ENTERSUB, OPf_STACKED,
351                                 append_elem(OP_LIST,
352                                     prepend_elem(OP_LIST, $2, $4),
353                                     newUNOP(OP_METHOD, 0, $1))); }
354         |       LSTOP listexpr
355                         { $$ = convert($1, 0, $2); }
356         |       FUNC '(' listexprcom ')'
357                         { $$ = convert($1, 0, $3); }
358         |       LSTOPSUB startsub block listexpr        %prec LSTOP
359                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
360                             append_elem(OP_LIST,
361                               prepend_elem(OP_LIST, newANONSUB($2, 0, $3), $4),
362                               $1)); }
363         ;
364
365 method  :       METHOD
366         |       scalar
367         ;
368
369 term    :       term ASSIGNOP term
370                         { $$ = newASSIGNOP(OPf_STACKED, $1, $2, $3); }
371         |       term POWOP term
372                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
373         |       term MULOP term
374                         {   if ($2 != OP_REPEAT)
375                                 scalar($1);
376                             $$ = newBINOP($2, 0, $1, scalar($3)); }
377         |       term ADDOP term
378                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
379         |       term SHIFTOP term
380                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
381         |       term RELOP term
382                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
383         |       term EQOP term
384                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
385         |       term BITANDOP term
386                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
387         |       term BITOROP term
388                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
389         |       term DOTDOT term
390                         { $$ = newRANGE($2, scalar($1), scalar($3));}
391         |       term ANDAND term
392                         { $$ = newLOGOP(OP_AND, 0, $1, $3); }
393         |       term OROR term
394                         { $$ = newLOGOP(OP_OR, 0, $1, $3); }
395         |       term '?' term ':' term
396                         { $$ = newCONDOP(0, $1, $3, $5); }
397         |       term MATCHOP term
398                         { $$ = bind_match($2, $1, $3); }
399
400         |       '-' term %prec UMINUS
401                         { $$ = newUNOP(OP_NEGATE, 0, scalar($2)); }
402         |       '+' term %prec UMINUS
403                         { $$ = $2; }
404         |       '!' term
405                         { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
406         |       '~' term
407                         { $$ = newUNOP(OP_COMPLEMENT, 0, scalar($2));}
408         |       REFGEN term
409                         { $$ = newUNOP(OP_REFGEN, 0, mod($2,OP_REFGEN)); }
410         |       term POSTINC
411                         { $$ = newUNOP(OP_POSTINC, 0,
412                                         mod(scalar($1), OP_POSTINC)); }
413         |       term POSTDEC
414                         { $$ = newUNOP(OP_POSTDEC, 0,
415                                         mod(scalar($1), OP_POSTDEC)); }
416         |       PREINC term
417                         { $$ = newUNOP(OP_PREINC, 0,
418                                         mod(scalar($2), OP_PREINC)); }
419         |       PREDEC term
420                         { $$ = newUNOP(OP_PREDEC, 0,
421                                         mod(scalar($2), OP_PREDEC)); }
422         |       local term      %prec UNIOP
423                         { $$ = localize($2,$1); }
424         |       '(' expr ')'
425                         { $$ = sawparens($2); }
426         |       '(' ')'
427                         { $$ = sawparens(newNULLLIST()); }
428         |       '[' expr ']'                            %prec '('
429                         { $$ = newANONLIST($2); }
430         |       '[' ']'                                 %prec '('
431                         { $$ = newANONLIST(Nullop); }
432         |       HASHBRACK expr ';' '}'                  %prec '('
433                         { $$ = newANONHASH($2); }
434         |       HASHBRACK ';' '}'                               %prec '('
435                         { $$ = newANONHASH(Nullop); }
436         |       ANONSUB startsub proto block                    %prec '('
437                         { $$ = newANONSUB($2, $3, $4); }
438         |       scalar  %prec '('
439                         { $$ = $1; }
440         |       star '{' expr ';' '}'
441                         { $$ = newBINOP(OP_GELEM, 0, newGVREF(0,$1), $3); }
442         |       star    %prec '('
443                         { $$ = $1; }
444         |       scalar '[' expr ']'     %prec '('
445                         { $$ = newBINOP(OP_AELEM, 0, oopsAV($1), scalar($3)); }
446         |       term ARROW '[' expr ']' %prec '('
447                         { $$ = newBINOP(OP_AELEM, 0,
448                                         ref(newAVREF($1),OP_RV2AV),
449                                         scalar($4));}
450         |       term '[' expr ']'       %prec '('
451                         { assertref($1); $$ = newBINOP(OP_AELEM, 0,
452                                         ref(newAVREF($1),OP_RV2AV),
453                                         scalar($3));}
454         |       hsh     %prec '('
455                         { $$ = $1; }
456         |       ary     %prec '('
457                         { $$ = $1; }
458         |       arylen  %prec '('
459                         { $$ = newUNOP(OP_AV2ARYLEN, 0, ref($1, OP_AV2ARYLEN));}
460         |       scalar '{' expr ';' '}' %prec '('
461                         { $$ = newBINOP(OP_HELEM, 0, oopsHV($1), jmaybe($3));
462                             expect = XOPERATOR; }
463         |       term ARROW '{' expr ';' '}'     %prec '('
464                         { $$ = newBINOP(OP_HELEM, 0,
465                                         ref(newHVREF($1),OP_RV2HV),
466                                         jmaybe($4));
467                             expect = XOPERATOR; }
468         |       term '{' expr ';' '}'   %prec '('
469                         { assertref($1); $$ = newBINOP(OP_HELEM, 0,
470                                         ref(newHVREF($1),OP_RV2HV),
471                                         jmaybe($3));
472                             expect = XOPERATOR; }
473         |       '(' expr ')' '[' expr ']'       %prec '('
474                         { $$ = newSLICEOP(0, $5, $2); }
475         |       '(' ')' '[' expr ']'    %prec '('
476                         { $$ = newSLICEOP(0, $4, Nullop); }
477         |       ary '[' expr ']'        %prec '('
478                         { $$ = prepend_elem(OP_ASLICE,
479                                 newOP(OP_PUSHMARK, 0),
480                                     newLISTOP(OP_ASLICE, 0,
481                                         list($3),
482                                         ref($1, OP_ASLICE))); }
483         |       ary '{' expr ';' '}'    %prec '('
484                         { $$ = prepend_elem(OP_HSLICE,
485                                 newOP(OP_PUSHMARK, 0),
486                                     newLISTOP(OP_HSLICE, 0,
487                                         list($3),
488                                         ref(oopsHV($1), OP_HSLICE)));
489                             expect = XOPERATOR; }
490         |       THING   %prec '('
491                         { $$ = $1; }
492         |       amper
493                         { $$ = newUNOP(OP_ENTERSUB, 0, scalar($1)); }
494         |       amper '(' ')'
495                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED, scalar($1)); }
496         |       amper '(' expr ')'
497                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
498                             append_elem(OP_LIST, $3, scalar($1))); }
499         |       NOAMP WORD listexpr
500                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
501                             append_elem(OP_LIST, $3, scalar($2))); }
502         |       DO term %prec UNIOP
503                         { $$ = newUNOP(OP_DOFILE, 0, scalar($2)); }
504         |       DO block        %prec '('
505                         { $$ = newUNOP(OP_NULL, OPf_SPECIAL, scope($2)); }
506         |       DO WORD '(' ')'
507                         { $$ = newUNOP(OP_ENTERSUB,
508                             OPf_SPECIAL|OPf_STACKED,
509                             prepend_elem(OP_LIST,
510                                 scalar(newCVREF(
511                                     (OPpENTERSUB_AMPER<<8),
512                                     scalar($2)
513                                 )),Nullop)); dep();}
514         |       DO WORD '(' expr ')'
515                         { $$ = newUNOP(OP_ENTERSUB,
516                             OPf_SPECIAL|OPf_STACKED,
517                             append_elem(OP_LIST,
518                                 $4,
519                                 scalar(newCVREF(
520                                     (OPpENTERSUB_AMPER<<8),
521                                     scalar($2)
522                                 )))); dep();}
523         |       DO scalar '(' ')'
524                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
525                             prepend_elem(OP_LIST,
526                                 scalar(newCVREF(0,scalar($2))), Nullop)); dep();}
527         |       DO scalar '(' expr ')'
528                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
529                             prepend_elem(OP_LIST,
530                                 $4,
531                                 scalar(newCVREF(0,scalar($2))))); dep();}
532         |       LOOPEX
533                         { $$ = newOP($1, OPf_SPECIAL);
534                             hints |= HINT_BLOCK_SCOPE; }
535         |       LOOPEX term
536                         { $$ = newLOOPEX($1,$2); }
537         |       NOTOP argexpr
538                         { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
539         |       UNIOP
540                         { $$ = newOP($1, 0); }
541         |       UNIOP block
542                         { $$ = newUNOP($1, 0, $2); }
543         |       UNIOP term
544                         { $$ = newUNOP($1, 0, $2); }
545         |       UNIOPSUB term
546                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
547                             append_elem(OP_LIST, $2, scalar($1))); }
548         |       FUNC0
549                         { $$ = newOP($1, 0); }
550         |       FUNC0 '(' ')'
551                         { $$ = newOP($1, 0); }
552         |       FUNC0SUB
553                         { $$ = newUNOP(OP_ENTERSUB, 0,
554                                 scalar($1)); }
555         |       FUNC1 '(' ')'
556                         { $$ = newOP($1, OPf_SPECIAL); }
557         |       FUNC1 '(' expr ')'
558                         { $$ = newUNOP($1, 0, $3); }
559         |       PMFUNC '(' term ')'
560                         { $$ = pmruntime($1, $3, Nullop); }
561         |       PMFUNC '(' term ',' term ')'
562                         { $$ = pmruntime($1, $3, $5); }
563         |       WORD
564         |       listop
565         ;
566
567 listexpr:       /* NULL */
568                         { $$ = Nullop; }
569         |       argexpr
570                         { $$ = $1; }
571         ;
572
573 listexprcom:    /* NULL */
574                         { $$ = Nullop; }
575         |       expr
576                         { $$ = $1; }
577         |       expr ','
578                         { $$ = $1; }
579         ;
580
581 local   :       LOCAL   { $$ = 0; }
582         |       MY      { $$ = 1; }
583         ;
584
585 my_scalar:      scalar
586                         { in_my = 0; $$ = my($1); }
587         ;
588
589 amper   :       '&' indirob
590                         { $$ = newCVREF($1,$2); }
591         ;
592
593 scalar  :       '$' indirob
594                         { $$ = newSVREF($2); }
595         ;
596
597 ary     :       '@' indirob
598                         { $$ = newAVREF($2); }
599         ;
600
601 hsh     :       '%' indirob
602                         { $$ = newHVREF($2); }
603         ;
604
605 arylen  :       DOLSHARP indirob
606                         { $$ = newAVREF($2); }
607         ;
608
609 star    :       '*' indirob
610                         { $$ = newGVREF(0,$2); }
611         ;
612
613 indirob :       WORD
614                         { $$ = scalar($1); }
615         |       scalar
616                         { $$ = scalar($1);  }
617         |       block
618                         { $$ = scope($1); }
619
620         |       PRIVATEREF
621                         { $$ = $1; }
622         ;
623
624 %% /* PROGRAM */