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1/* perly.y
2 *
3 * Copyright (c) 1991-2002, 2003, 2004 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 who wander are lost.'
13 */
14
15/* This file holds the grammar for the Perl language. If edited, you need
16 * to run regen_perly.pl, which re-creates the files perly.h, perly.tab
17 * and perly.act which are derived from this.
18 *
19 * The main job of of this grammar is to call the various newFOO()
20 * functions in op.c to build a syntax tree of OP structs.
21 * It relies in the lexer in toke.c to do the tokenizing.
22 */
23
24/* Make the parser re-entrant. */
25
26%pure_parser
27
28%start prog
29
30%union {
31 I32 ival;
32 char *pval;
33 OP *opval;
34 GV *gvval;
35}
36
37%token <ival> '{'
38
39%token <opval> WORD METHOD FUNCMETH THING PMFUNC PRIVATEREF
40%token <opval> FUNC0SUB UNIOPSUB LSTOPSUB
41%token <pval> LABEL
42%token <ival> FORMAT SUB ANONSUB PACKAGE USE
43%token <ival> WHILE UNTIL IF UNLESS ELSE ELSIF CONTINUE FOR
44%token <ival> LOOPEX DOTDOT
45%token <ival> FUNC0 FUNC1 FUNC UNIOP LSTOP
46%token <ival> RELOP EQOP MULOP ADDOP
47%token <ival> DOLSHARP DO HASHBRACK NOAMP
48%token <ival> LOCAL MY MYSUB
49%token COLONATTR
50
51%type <ival> prog decl format startsub startanonsub startformsub
52%type <ival> progstart remember mremember '&' savescope
53%type <opval> block mblock lineseq line loop cond else
54%type <opval> expr term subscripted scalar ary hsh arylen star amper sideff
55%type <opval> argexpr nexpr texpr iexpr mexpr mnexpr mtexpr miexpr
56%type <opval> listexpr listexprcom indirob listop method
57%type <opval> formname subname proto subbody cont my_scalar
58%type <opval> subattrlist myattrlist mysubrout myattrterm myterm
59%type <opval> termbinop termunop anonymous termdo
60%type <pval> label
61
62%nonassoc PREC_LOW
63%nonassoc LOOPEX
64
65%left <ival> OROP DOROP
66%left ANDOP
67%right NOTOP
68%nonassoc LSTOP LSTOPSUB
69%left ','
70%right <ival> ASSIGNOP
71%right '?' ':'
72%nonassoc DOTDOT
73%left OROR DORDOR
74%left ANDAND
75%left <ival> BITOROP
76%left <ival> BITANDOP
77%nonassoc EQOP
78%nonassoc RELOP
79%nonassoc UNIOP UNIOPSUB
80%left <ival> SHIFTOP
81%left ADDOP
82%left MULOP
83%left <ival> MATCHOP
84%right '!' '~' UMINUS REFGEN
85%right <ival> POWOP
86%nonassoc PREINC PREDEC POSTINC POSTDEC
87%left ARROW
88%nonassoc <ival> ')'
89%left '('
90%left '[' '{'
91
92%% /* RULES */
93
94/* The whole program */
95prog : progstart
96 /*CONTINUED*/ lineseq
97 { $$ = $1; newPROG(block_end($1,$2)); }
98 ;
99
100/* An ordinary block */
101block : '{' remember lineseq '}'
102 { if (PL_copline > (line_t)$1)
103 PL_copline = (line_t)$1;
104 $$ = block_end($2, $3); }
105 ;
106
107remember: /* NULL */ /* start a full lexical scope */
108 { $$ = block_start(TRUE); }
109 ;
110
111progstart:
112 {
113 PL_expect = XSTATE; $$ = block_start(TRUE);
114 }
115 ;
116
117
118mblock : '{' mremember lineseq '}'
119 { if (PL_copline > (line_t)$1)
120 PL_copline = (line_t)$1;
121 $$ = block_end($2, $3); }
122 ;
123
124mremember: /* NULL */ /* start a partial lexical scope */
125 { $$ = block_start(FALSE); }
126 ;
127
128savescope: /* NULL */ /* remember stack pos in case of error */
129 { $$ = PL_savestack_ix; }
130
131/* A collection of "lines" in the program */
132lineseq : /* NULL */
133 { $$ = Nullop; }
134 | lineseq decl
135 { $$ = $1; }
136 | lineseq savescope line
137 { LEAVE_SCOPE($2);
138 $$ = append_list(OP_LINESEQ,
139 (LISTOP*)$1, (LISTOP*)$3);
140 PL_pad_reset_pending = TRUE;
141 if ($1 && $3) PL_hints |= HINT_BLOCK_SCOPE; }
142 ;
143
144/* A "line" in the program */
145line : label cond
146 { $$ = newSTATEOP(0, $1, $2); }
147 | loop /* loops add their own labels */
148 | label ';'
149 { if ($1 != Nullch) {
150 $$ = newSTATEOP(0, $1, newOP(OP_NULL, 0));
151 }
152 else {
153 $$ = Nullop;
154 PL_copline = NOLINE;
155 }
156 PL_expect = XSTATE; }
157 | label sideff ';'
158 { $$ = newSTATEOP(0, $1, $2);
159 PL_expect = XSTATE; }
160 ;
161
162/* An expression which may have a side-effect */
163sideff : error
164 { $$ = Nullop; }
165 | expr
166 { $$ = $1; }
167 | expr IF expr
168 { $$ = newLOGOP(OP_AND, 0, $3, $1); }
169 | expr UNLESS expr
170 { $$ = newLOGOP(OP_OR, 0, $3, $1); }
171 | expr WHILE expr
172 { $$ = newLOOPOP(OPf_PARENS, 1, scalar($3), $1); }
173 | expr UNTIL iexpr
174 { $$ = newLOOPOP(OPf_PARENS, 1, $3, $1);}
175 | expr FOR expr
176 { $$ = newFOROP(0, Nullch, (line_t)$2,
177 Nullop, $3, $1, Nullop); }
178 ;
179
180/* else and elsif blocks */
181else : /* NULL */
182 { $$ = Nullop; }
183 | ELSE mblock
184 { ($2)->op_flags |= OPf_PARENS; $$ = scope($2); }
185 | ELSIF '(' mexpr ')' mblock else
186 { PL_copline = (line_t)$1;
187 $$ = newCONDOP(0, $3, scope($5), $6);
188 PL_hints |= HINT_BLOCK_SCOPE; }
189 ;
190
191/* Real conditional expressions */
192cond : IF '(' remember mexpr ')' mblock else
193 { PL_copline = (line_t)$1;
194 $$ = block_end($3,
195 newCONDOP(0, $4, scope($6), $7)); }
196 | UNLESS '(' remember miexpr ')' mblock else
197 { PL_copline = (line_t)$1;
198 $$ = block_end($3,
199 newCONDOP(0, $4, scope($6), $7)); }
200 ;
201
202/* Continue blocks */
203cont : /* NULL */
204 { $$ = Nullop; }
205 | CONTINUE block
206 { $$ = scope($2); }
207 ;
208
209/* Loops: while, until, for, and a bare block */
210loop : label WHILE '(' remember mtexpr ')' mblock cont
211 { PL_copline = (line_t)$2;
212 $$ = block_end($4,
213 newSTATEOP(0, $1,
214 newWHILEOP(0, 1, (LOOP*)Nullop,
215 $2, $5, $7, $8))); }
216 | label UNTIL '(' remember miexpr ')' mblock cont
217 { PL_copline = (line_t)$2;
218 $$ = block_end($4,
219 newSTATEOP(0, $1,
220 newWHILEOP(0, 1, (LOOP*)Nullop,
221 $2, $5, $7, $8))); }
222 | label FOR MY remember my_scalar '(' mexpr ')' mblock cont
223 { $$ = block_end($4,
224 newFOROP(0, $1, (line_t)$2, $5, $7, $9, $10)); }
225 | label FOR scalar '(' remember mexpr ')' mblock cont
226 { $$ = block_end($5,
227 newFOROP(0, $1, (line_t)$2, mod($3, OP_ENTERLOOP),
228 $6, $8, $9)); }
229 | label FOR '(' remember mexpr ')' mblock cont
230 { $$ = block_end($4,
231 newFOROP(0, $1, (line_t)$2, Nullop, $5, $7, $8)); }
232 | label FOR '(' remember mnexpr ';' mtexpr ';' mnexpr ')' mblock
233 /* basically fake up an initialize-while lineseq */
234 { OP *forop;
235 PL_copline = (line_t)$2;
236 forop = newSTATEOP(0, $1,
237 newWHILEOP(0, 1, (LOOP*)Nullop,
238 $2, scalar($7),
239 $11, $9));
240 if ($5) {
241 forop = append_elem(OP_LINESEQ,
242 newSTATEOP(0, ($1?savepv($1):Nullch),
243 $5),
244 forop);
245 }
246
247 $$ = block_end($4, forop); }
248 | label block cont /* a block is a loop that happens once */
249 { $$ = newSTATEOP(0, $1,
250 newWHILEOP(0, 1, (LOOP*)Nullop,
251 NOLINE, Nullop, $2, $3)); }
252 ;
253
254/* Normal expression */
255nexpr : /* NULL */
256 { $$ = Nullop; }
257 | sideff
258 ;
259
260/* Boolean expression */
261texpr : /* NULL means true */
262 { (void)scan_num("1", &yylval); $$ = yylval.opval; }
263 | expr
264 ;
265
266/* Inverted boolean expression */
267iexpr : expr
268 { $$ = invert(scalar($1)); }
269 ;
270
271/* Expression with its own lexical scope */
272mexpr : expr
273 { $$ = $1; intro_my(); }
274 ;
275
276mnexpr : nexpr
277 { $$ = $1; intro_my(); }
278 ;
279
280mtexpr : texpr
281 { $$ = $1; intro_my(); }
282 ;
283
284miexpr : iexpr
285 { $$ = $1; intro_my(); }
286 ;
287
288/* Optional "MAIN:"-style loop labels */
289label : /* empty */
290 { $$ = Nullch; }
291 | LABEL
292 ;
293
294/* Some kind of declaration - does not take part in the parse tree */
295decl : format
296 { $$ = 0; }
297 | subrout
298 { $$ = 0; }
299 | mysubrout
300 { $$ = 0; }
301 | package
302 { $$ = 0; }
303 | use
304 { $$ = 0; }
305 ;
306
307format : FORMAT startformsub formname block
308 { newFORM($2, $3, $4); }
309 ;
310
311formname: WORD { $$ = $1; }
312 | /* NULL */ { $$ = Nullop; }
313 ;
314
315/* Unimplemented "my sub foo { }" */
316mysubrout: MYSUB startsub subname proto subattrlist subbody
317 { newMYSUB($2, $3, $4, $5, $6); }
318 ;
319
320/* Subroutine definition */
321subrout : SUB startsub subname proto subattrlist subbody
322 { newATTRSUB($2, $3, $4, $5, $6); }
323 ;
324
325startsub: /* NULL */ /* start a regular subroutine scope */
326 { $$ = start_subparse(FALSE, 0); }
327 ;
328
329startanonsub: /* NULL */ /* start an anonymous subroutine scope */
330 { $$ = start_subparse(FALSE, CVf_ANON); }
331 ;
332
333startformsub: /* NULL */ /* start a format subroutine scope */
334 { $$ = start_subparse(TRUE, 0); }
335 ;
336
337/* Name of a subroutine - must be a bareword, could be special */
338subname : WORD { STRLEN n_a; char *name = SvPV(((SVOP*)$1)->op_sv,n_a);
339 if (strEQ(name, "BEGIN") || strEQ(name, "END")
340 || strEQ(name, "INIT") || strEQ(name, "CHECK"))
341 CvSPECIAL_on(PL_compcv);
342 $$ = $1; }
343 ;
344
345/* Subroutine prototype */
346proto : /* NULL */
347 { $$ = Nullop; }
348 | THING
349 ;
350
351/* Optional list of subroutine attributes */
352subattrlist: /* NULL */
353 { $$ = Nullop; }
354 | COLONATTR THING
355 { $$ = $2; }
356 | COLONATTR
357 { $$ = Nullop; }
358 ;
359
360/* List of attributes for a "my" variable declaration */
361myattrlist: COLONATTR THING
362 { $$ = $2; }
363 | COLONATTR
364 { $$ = Nullop; }
365 ;
366
367/* Subroutine body - either null or a block */
368subbody : block { $$ = $1; }
369 | ';' { $$ = Nullop; PL_expect = XSTATE; }
370 ;
371
372package : PACKAGE WORD ';'
373 { package($2); }
374 ;
375
376use : USE startsub
377 { CvSPECIAL_on(PL_compcv); /* It's a BEGIN {} */ }
378 WORD WORD listexpr ';'
379 { utilize($1, $2, $4, $5, $6); }
380 ;
381
382/* Ordinary expressions; logical combinations */
383expr : expr ANDOP expr
384 { $$ = newLOGOP(OP_AND, 0, $1, $3); }
385 | expr OROP expr
386 { $$ = newLOGOP($2, 0, $1, $3); }
387 | expr DOROP expr
388 { $$ = newLOGOP(OP_DOR, 0, $1, $3); }
389 | argexpr %prec PREC_LOW
390 ;
391
392/* Expressions are a list of terms joined by commas */
393argexpr : argexpr ','
394 { $$ = $1; }
395 | argexpr ',' term
396 { $$ = append_elem(OP_LIST, $1, $3); }
397 | term %prec PREC_LOW
398 ;
399
400/* List operators */
401listop : LSTOP indirob argexpr /* print $fh @args */
402 { $$ = convert($1, OPf_STACKED,
403 prepend_elem(OP_LIST, newGVREF($1,$2), $3) ); }
404 | FUNC '(' indirob expr ')' /* print ($fh @args */
405 { $$ = convert($1, OPf_STACKED,
406 prepend_elem(OP_LIST, newGVREF($1,$3), $4) ); }
407 | term ARROW method '(' listexprcom ')' /* $foo->bar(list) */
408 { $$ = convert(OP_ENTERSUB, OPf_STACKED,
409 append_elem(OP_LIST,
410 prepend_elem(OP_LIST, scalar($1), $5),
411 newUNOP(OP_METHOD, 0, $3))); }
412 | term ARROW method /* $foo->bar */
413 { $$ = convert(OP_ENTERSUB, OPf_STACKED,
414 append_elem(OP_LIST, scalar($1),
415 newUNOP(OP_METHOD, 0, $3))); }
416 | METHOD indirob listexpr /* new Class @args */
417 { $$ = convert(OP_ENTERSUB, OPf_STACKED,
418 append_elem(OP_LIST,
419 prepend_elem(OP_LIST, $2, $3),
420 newUNOP(OP_METHOD, 0, $1))); }
421 | FUNCMETH indirob '(' listexprcom ')' /* method $object (@args) */
422 { $$ = convert(OP_ENTERSUB, OPf_STACKED,
423 append_elem(OP_LIST,
424 prepend_elem(OP_LIST, $2, $4),
425 newUNOP(OP_METHOD, 0, $1))); }
426 | LSTOP listexpr /* print @args */
427 { $$ = convert($1, 0, $2); }
428 | FUNC '(' listexprcom ')' /* print (@args) */
429 { $$ = convert($1, 0, $3); }
430 | LSTOPSUB startanonsub block /* map { foo } ... */
431 { $3 = newANONATTRSUB($2, 0, Nullop, $3); }
432 listexpr %prec LSTOP /* ... @bar */
433 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
434 append_elem(OP_LIST,
435 prepend_elem(OP_LIST, $3, $5), $1)); }
436 ;
437
438/* Names of methods. May use $object->$methodname */
439method : METHOD
440 | scalar
441 ;
442
443/* Some kind of subscripted expression */
444subscripted: star '{' expr ';' '}' /* *main::{something} */
445 /* In this and all the hash accessors, ';' is
446 * provided by the tokeniser */
447 { $$ = newBINOP(OP_GELEM, 0, $1, scalar($3));
448 PL_expect = XOPERATOR; }
449 | scalar '[' expr ']' /* $array[$element] */
450 { $$ = newBINOP(OP_AELEM, 0, oopsAV($1), scalar($3)); }
451 | term ARROW '[' expr ']' /* somearef->[$element] */
452 { $$ = newBINOP(OP_AELEM, 0,
453 ref(newAVREF($1),OP_RV2AV),
454 scalar($4));}
455 | subscripted '[' expr ']' /* $foo->[$bar]->[$baz] */
456 { $$ = newBINOP(OP_AELEM, 0,
457 ref(newAVREF($1),OP_RV2AV),
458 scalar($3));}
459 | scalar '{' expr ';' '}' /* $foo->{bar();} */
460 { $$ = newBINOP(OP_HELEM, 0, oopsHV($1), jmaybe($3));
461 PL_expect = XOPERATOR; }
462 | term ARROW '{' expr ';' '}' /* somehref->{bar();} */
463 { $$ = newBINOP(OP_HELEM, 0,
464 ref(newHVREF($1),OP_RV2HV),
465 jmaybe($4));
466 PL_expect = XOPERATOR; }
467 | subscripted '{' expr ';' '}' /* $foo->[bar]->{baz;} */
468 { $$ = newBINOP(OP_HELEM, 0,
469 ref(newHVREF($1),OP_RV2HV),
470 jmaybe($3));
471 PL_expect = XOPERATOR; }
472 | term ARROW '(' ')' /* $subref->() */
473 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
474 newCVREF(0, scalar($1))); }
475 | term ARROW '(' expr ')' /* $subref->(@args) */
476 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
477 append_elem(OP_LIST, $4,
478 newCVREF(0, scalar($1)))); }
479
480 | subscripted '(' expr ')' /* $foo->{bar}->(@args) */
481 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
482 append_elem(OP_LIST, $3,
483 newCVREF(0, scalar($1)))); }
484 | subscripted '(' ')' /* $foo->{bar}->() */
485 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
486 newCVREF(0, scalar($1))); }
487 ;
488
489/* Binary operators between terms */
490termbinop : term ASSIGNOP term /* $x = $y */
491 { $$ = newASSIGNOP(OPf_STACKED, $1, $2, $3); }
492 | term POWOP term /* $x ** $y */
493 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
494 | term MULOP term /* $x * $y, $x x $y */
495 { if ($2 != OP_REPEAT)
496 scalar($1);
497 $$ = newBINOP($2, 0, $1, scalar($3)); }
498 | term ADDOP term /* $x + $y */
499 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
500 | term SHIFTOP term /* $x >> $y, $x << $y */
501 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
502 | term RELOP term /* $x > $y, etc. */
503 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
504 | term EQOP term /* $x == $y, $x eq $y */
505 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
506 | term BITANDOP term /* $x & $y */
507 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
508 | term BITOROP term /* $x | $y */
509 { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
510 | term DOTDOT term /* $x..$y, $x...$y */
511 { $$ = newRANGE($2, scalar($1), scalar($3));}
512 | term ANDAND term /* $x && $y */
513 { $$ = newLOGOP(OP_AND, 0, $1, $3); }
514 | term OROR term /* $x || $y */
515 { $$ = newLOGOP(OP_OR, 0, $1, $3); }
516 | term DORDOR term /* $x // $y */
517 { $$ = newLOGOP(OP_DOR, 0, $1, $3); }
518 | term MATCHOP term /* $x =~ /$y/ */
519 { $$ = bind_match($2, $1, $3); }
520 ;
521
522/* Unary operators and terms */
523termunop : '-' term %prec UMINUS /* -$x */
524 { $$ = newUNOP(OP_NEGATE, 0, scalar($2)); }
525 | '+' term %prec UMINUS /* +$x */
526 { $$ = $2; }
527 | '!' term /* !$x */
528 { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
529 | '~' term /* ~$x */
530 { $$ = newUNOP(OP_COMPLEMENT, 0, scalar($2));}
531 | term POSTINC /* $x++ */
532 { $$ = newUNOP(OP_POSTINC, 0,
533 mod(scalar($1), OP_POSTINC)); }
534 | term POSTDEC /* $x-- */
535 { $$ = newUNOP(OP_POSTDEC, 0,
536 mod(scalar($1), OP_POSTDEC)); }
537 | PREINC term /* ++$x */
538 { $$ = newUNOP(OP_PREINC, 0,
539 mod(scalar($2), OP_PREINC)); }
540 | PREDEC term /* --$x */
541 { $$ = newUNOP(OP_PREDEC, 0,
542 mod(scalar($2), OP_PREDEC)); }
543
544 ;
545
546/* Constructors for anonymous data */
547anonymous: '[' expr ']'
548 { $$ = newANONLIST($2); }
549 | '[' ']'
550 { $$ = newANONLIST(Nullop); }
551 | HASHBRACK expr ';' '}' %prec '(' /* { foo => "Bar" } */
552 { $$ = newANONHASH($2); }
553 | HASHBRACK ';' '}' %prec '(' /* { } (';' by tokener) */
554 { $$ = newANONHASH(Nullop); }
555 | ANONSUB startanonsub proto subattrlist block %prec '('
556 { $$ = newANONATTRSUB($2, $3, $4, $5); }
557
558 ;
559
560/* Things called with "do" */
561termdo : DO term %prec UNIOP /* do $filename */
562 { $$ = dofile($2); }
563 | DO block %prec '(' /* do { code */
564 { $$ = newUNOP(OP_NULL, OPf_SPECIAL, scope($2)); }
565 | DO WORD '(' ')' /* do somesub() */
566 { $$ = newUNOP(OP_ENTERSUB,
567 OPf_SPECIAL|OPf_STACKED,
568 prepend_elem(OP_LIST,
569 scalar(newCVREF(
570 (OPpENTERSUB_AMPER<<8),
571 scalar($2)
572 )),Nullop)); dep();}
573 | DO WORD '(' expr ')' /* do somesub(@args) */
574 { $$ = newUNOP(OP_ENTERSUB,
575 OPf_SPECIAL|OPf_STACKED,
576 append_elem(OP_LIST,
577 $4,
578 scalar(newCVREF(
579 (OPpENTERSUB_AMPER<<8),
580 scalar($2)
581 )))); dep();}
582 | DO scalar '(' ')' /* do $subref () */
583 { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
584 prepend_elem(OP_LIST,
585 scalar(newCVREF(0,scalar($2))), Nullop)); dep();}
586 | DO scalar '(' expr ')' /* do $subref (@args) */
587 { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
588 prepend_elem(OP_LIST,
589 $4,
590 scalar(newCVREF(0,scalar($2))))); dep();}
591
592 ;
593
594term : termbinop
595 | termunop
596 | anonymous
597 | termdo
598 | term '?' term ':' term
599 { $$ = newCONDOP(0, $1, $3, $5); }
600 | REFGEN term /* \$x, \@y, \%z */
601 { $$ = newUNOP(OP_REFGEN, 0, mod($2,OP_REFGEN)); }
602 | myattrterm %prec UNIOP
603 { $$ = $1; }
604 | LOCAL term %prec UNIOP
605 { $$ = localize($2,$1); }
606 | '(' expr ')'
607 { $$ = sawparens($2); }
608 | '(' ')'
609 { $$ = sawparens(newNULLLIST()); }
610 | scalar %prec '('
611 { $$ = $1; }
612 | star %prec '('
613 { $$ = $1; }
614 | hsh %prec '('
615 { $$ = $1; }
616 | ary %prec '('
617 { $$ = $1; }
618 | arylen %prec '(' /* $#x, $#{ something } */
619 { $$ = newUNOP(OP_AV2ARYLEN, 0, ref($1, OP_AV2ARYLEN));}
620 | subscripted
621 { $$ = $1; }
622 | '(' expr ')' '[' expr ']' /* list slice */
623 { $$ = newSLICEOP(0, $5, $2); }
624 | '(' ')' '[' expr ']' /* empty list slice! */
625 { $$ = newSLICEOP(0, $4, Nullop); }
626 | ary '[' expr ']' /* array slice */
627 { $$ = prepend_elem(OP_ASLICE,
628 newOP(OP_PUSHMARK, 0),
629 newLISTOP(OP_ASLICE, 0,
630 list($3),
631 ref($1, OP_ASLICE))); }
632 | ary '{' expr ';' '}' /* @hash{@keys} */
633 { $$ = prepend_elem(OP_HSLICE,
634 newOP(OP_PUSHMARK, 0),
635 newLISTOP(OP_HSLICE, 0,
636 list($3),
637 ref(oopsHV($1), OP_HSLICE)));
638 PL_expect = XOPERATOR; }
639 | THING %prec '('
640 { $$ = $1; }
641 | amper /* &foo; */
642 { $$ = newUNOP(OP_ENTERSUB, 0, scalar($1)); }
643 | amper '(' ')' /* &foo() */
644 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED, scalar($1)); }
645 | amper '(' expr ')' /* &foo(@args) */
646 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
647 append_elem(OP_LIST, $3, scalar($1))); }
648 | NOAMP WORD listexpr /* foo(@args) */
649 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
650 append_elem(OP_LIST, $3, scalar($2))); }
651 | LOOPEX /* loop exiting command (goto, last, dump, etc) */
652 { $$ = newOP($1, OPf_SPECIAL);
653 PL_hints |= HINT_BLOCK_SCOPE; }
654 | LOOPEX term
655 { $$ = newLOOPEX($1,$2); }
656 | NOTOP argexpr /* not $foo */
657 { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
658 | UNIOP /* Unary op, $_ implied */
659 { $$ = newOP($1, 0); }
660 | UNIOP block /* eval { foo } */
661 { $$ = newUNOP($1, 0, $2); }
662 | UNIOP term /* Unary op */
663 { $$ = newUNOP($1, 0, $2); }
664 | UNIOPSUB term /* Sub treated as unop */
665 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
666 append_elem(OP_LIST, $2, scalar($1))); }
667 | FUNC0 /* Nullary operator */
668 { $$ = newOP($1, 0); }
669 | FUNC0 '(' ')'
670 { $$ = newOP($1, 0); }
671 | FUNC0SUB /* Sub treated as nullop */
672 { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
673 scalar($1)); }
674 | FUNC1 '(' ')' /* not () */
675 { $$ = newOP($1, OPf_SPECIAL); }
676 | FUNC1 '(' expr ')' /* not($foo) */
677 { $$ = newUNOP($1, 0, $3); }
678 | PMFUNC '(' term ')' /* /foo/ */
679 { $$ = pmruntime($1, $3, Nullop); }
680 | PMFUNC '(' term ',' term ')' /* s/foo/bar/ (or tr) */
681 { $$ = pmruntime($1, $3, $5); }
682 | WORD
683 | listop
684 ;
685
686/* "my" declarations, with optional attributes */
687myattrterm: MY myterm myattrlist
688 { $$ = my_attrs($2,$3); }
689 | MY myterm
690 { $$ = localize($2,$1); }
691 ;
692
693/* Things that can be "my"'d */
694myterm : '(' expr ')'
695 { $$ = sawparens($2); }
696 | '(' ')'
697 { $$ = sawparens(newNULLLIST()); }
698 | scalar %prec '('
699 { $$ = $1; }
700 | hsh %prec '('
701 { $$ = $1; }
702 | ary %prec '('
703 { $$ = $1; }
704 ;
705
706/* Basic list expressions */
707listexpr: /* NULL */ %prec PREC_LOW
708 { $$ = Nullop; }
709 | argexpr %prec PREC_LOW
710 { $$ = $1; }
711 ;
712
713listexprcom: /* NULL */
714 { $$ = Nullop; }
715 | expr
716 { $$ = $1; }
717 | expr ','
718 { $$ = $1; }
719 ;
720
721/* A little bit of trickery to make "for my $foo (@bar)" actually be
722 lexical */
723my_scalar: scalar
724 { PL_in_my = 0; $$ = my($1); }
725 ;
726
727amper : '&' indirob
728 { $$ = newCVREF($1,$2); }
729 ;
730
731scalar : '$' indirob
732 { $$ = newSVREF($2); }
733 ;
734
735ary : '@' indirob
736 { $$ = newAVREF($2); }
737 ;
738
739hsh : '%' indirob
740 { $$ = newHVREF($2); }
741 ;
742
743arylen : DOLSHARP indirob
744 { $$ = newAVREF($2); }
745 ;
746
747star : '*' indirob
748 { $$ = newGVREF(0,$2); }
749 ;
750
751/* Indirect objects */
752indirob : WORD
753 { $$ = scalar($1); }
754 | scalar %prec PREC_LOW
755 { $$ = scalar($1); }
756 | block
757 { $$ = scope($1); }
758
759 | PRIVATEREF
760 { $$ = $1; }
761 ;