This is my patch patch.1i for perl5.001.
[perl.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 <pval> LABEL
40 %token <ival> FORMAT SUB ANONSUB PACKAGE USE
41 %token <ival> WHILE UNTIL IF UNLESS ELSE ELSIF CONTINUE FOR
42 %token <ival> LOOPEX DOTDOT
43 %token <ival> FUNC0 FUNC1 FUNC
44 %token <ival> RELOP EQOP MULOP ADDOP
45 %token <ival> DOLSHARP DO LOCAL HASHBRACK NOAMP
46
47 %type <ival> prog decl format remember startsub
48 %type <opval> block lineseq line loop cond nexpr else argexpr
49 %type <opval> expr term scalar ary hsh arylen star amper sideff
50 %type <opval> listexpr listexprcom indirob
51 %type <opval> texpr listop method
52 %type <pval> label
53 %type <opval> cont
54
55 %left <ival> OROP
56 %left ANDOP
57 %left NOTOP
58 %nonassoc <ival> LSTOP
59 %left ','
60 %right <ival> ASSIGNOP
61 %right '?' ':'
62 %nonassoc DOTDOT
63 %left OROR
64 %left ANDAND
65 %left <ival> BITOROP
66 %left <ival> BITANDOP
67 %nonassoc EQOP
68 %nonassoc RELOP
69 %nonassoc <ival> UNIOP
70 %left <ival> SHIFTOP
71 %left ADDOP
72 %left MULOP
73 %left <ival> MATCHOP
74 %right '!' '~' UMINUS REFGEN
75 %right <ival> POWOP
76 %nonassoc PREINC PREDEC POSTINC POSTDEC
77 %left ARROW
78 %left '('
79
80 %% /* RULES */
81
82 prog    :       /* NULL */
83                 {
84 #if defined(YYDEBUG) && defined(DEBUGGING)
85                     yydebug = (debug & 1);
86 #endif
87                     expect = XSTATE;
88                 }
89         /*CONTINUED*/   lineseq
90                         { newPROG($2); }
91         ;
92
93 block   :       '{' remember lineseq '}'
94                         { $$ = block_end($1,$2,$3); }
95         ;
96
97 remember:       /* NULL */      /* start a lexical scope */
98                         { $$ = block_start(); }
99         ;
100
101 lineseq :       /* NULL */
102                         { $$ = Nullop; }
103         |       lineseq decl
104                         { $$ = $1; }
105         |       lineseq line
106                         {   $$ = append_list(OP_LINESEQ,
107                                 (LISTOP*)$1, (LISTOP*)$2);
108                             pad_reset_pending = TRUE;
109                             if ($1 && $2) hints |= HINT_BLOCK_SCOPE; }
110         ;
111
112 line    :       label cond
113                         { $$ = newSTATEOP(0, $1, $2); }
114         |       loop    /* loops add their own labels */
115         |       label ';'
116                         { if ($1 != Nullch) {
117                               $$ = newSTATEOP(0, $1, newOP(OP_NULL, 0));
118                             }
119                             else {
120                               $$ = Nullop;
121                               copline = NOLINE;
122                             }
123                             expect = XSTATE; }
124         |       label sideff ';'
125                         { $$ = newSTATEOP(0, $1, $2);
126                           expect = XSTATE; }
127         ;
128
129 sideff  :       error
130                         { $$ = Nullop; }
131         |       expr
132                         { $$ = $1; }
133         |       expr IF expr
134                         { $$ = newLOGOP(OP_AND, 0, $3, $1); }
135         |       expr UNLESS expr
136                         { $$ = newLOGOP(OP_OR, 0, $3, $1); }
137         |       expr WHILE expr
138                         { $$ = newLOOPOP(OPf_PARENS, 1, scalar($3), $1); }
139         |       expr UNTIL expr
140                         { $$ = newLOOPOP(OPf_PARENS, 1, invert(scalar($3)), $1);}
141         ;
142
143 else    :       /* NULL */
144                         { $$ = Nullop; }
145         |       ELSE block
146                         { $$ = scope($2); }
147         |       ELSIF '(' expr ')' block else
148                         { copline = $1;
149                             $$ = newSTATEOP(0, 0,
150                                 newCONDOP(0, $3, scope($5), $6)); }
151         ;
152
153 cond    :       IF '(' expr ')' block else
154                         { copline = $1;
155                             $$ = newCONDOP(0, $3, scope($5), $6); }
156         |       UNLESS '(' expr ')' block else
157                         { copline = $1;
158                             $$ = newCONDOP(0,
159                                 invert(scalar($3)), scope($5), $6); }
160         |       IF block block else
161                         { copline = $1;
162                             deprecate("if BLOCK BLOCK");
163                             $$ = newCONDOP(0, scope($2), scope($3), $4); }
164         |       UNLESS block block else
165                         { copline = $1;
166                             deprecate("unless BLOCK BLOCK");
167                             $$ = newCONDOP(0, invert(scalar(scope($2))),
168                                                 scope($3), $4); }
169         ;
170
171 cont    :       /* NULL */
172                         { $$ = Nullop; }
173         |       CONTINUE block
174                         { $$ = scope($2); }
175         ;
176
177 loop    :       label WHILE '(' texpr ')' block cont
178                         { copline = $2;
179                             $$ = newSTATEOP(0, $1,
180                                     newWHILEOP(0, 1, (LOOP*)Nullop,
181                                         $4, $6, $7) ); }
182         |       label UNTIL '(' expr ')' block cont
183                         { copline = $2;
184                             $$ = newSTATEOP(0, $1,
185                                     newWHILEOP(0, 1, (LOOP*)Nullop,
186                                         invert(scalar($4)), $6, $7) ); }
187         |       label WHILE block block cont
188                         { copline = $2;
189                             $$ = newSTATEOP(0, $1,
190                                     newWHILEOP(0, 1, (LOOP*)Nullop,
191                                         scope($3), $4, $5) ); }
192         |       label UNTIL block block cont
193                         { copline = $2;
194                             $$ = newSTATEOP(0, $1,
195                                     newWHILEOP(0, 1, (LOOP*)Nullop,
196                                         invert(scalar(scope($3))), $4, $5)); }
197         |       label FOR scalar '(' expr ')' block cont
198                         { $$ = newFOROP(0, $1, $2, mod($3, OP_ENTERLOOP),
199                                 $5, $7, $8); }
200         |       label FOR '(' expr ')' block cont
201                         { $$ = newFOROP(0, $1, $2, Nullop, $4, $6, $7); }
202         |       label FOR '(' nexpr ';' texpr ';' nexpr ')' block
203                         /* basically fake up an initialize-while lineseq */
204                         {  copline = $2;
205                             $$ = append_elem(OP_LINESEQ,
206                                     newSTATEOP(0, $1, scalar($4)),
207                                     newSTATEOP(0, $1,
208                                         newWHILEOP(0, 1, (LOOP*)Nullop,
209                                             scalar($6), $10, scalar($8)) )); }
210         |       label block cont  /* a block is a loop that happens once */
211                         { $$ = newSTATEOP(0,
212                                 $1, newWHILEOP(0, 1, (LOOP*)Nullop,
213                                         Nullop, $2, $3)); }
214         ;
215
216 nexpr   :       /* NULL */
217                         { $$ = Nullop; }
218         |       sideff
219         ;
220
221 texpr   :       /* NULL means true */
222                         { (void)scan_num("1"); $$ = yylval.opval; }
223         |       expr
224         ;
225
226 label   :       /* empty */
227                         { $$ = Nullch; }
228         |       LABEL
229         ;
230
231 decl    :       format
232                         { $$ = 0; }
233         |       subrout
234                         { $$ = 0; }
235         |       package
236                         { $$ = 0; }
237         |       use
238                         { $$ = 0; }
239         ;
240
241 format  :       FORMAT startsub WORD block
242                         { newFORM($2, $3, $4); }
243         |       FORMAT startsub block
244                         { newFORM($2, Nullop, $3); }
245         ;
246
247 subrout :       SUB startsub WORD block
248                         { newSUB($2, $3, $4); }
249         |       SUB startsub WORD ';'
250                         { newSUB($2, $3, Nullop); expect = XSTATE; }
251         ;
252
253 startsub:       /* NULL */      /* start a subroutine scope */
254                         { $$ = start_subparse(); }
255         ;
256
257 package :       PACKAGE WORD ';'
258                         { package($2); }
259         |       PACKAGE ';'
260                         { package(Nullop); }
261         ;
262
263 use     :       USE WORD listexpr ';'
264                         { utilize($1, $2, $3); }
265         ;
266
267 expr    :       expr ANDOP expr
268                         { $$ = newLOGOP(OP_AND, 0, $1, $3); }
269         |       expr OROP expr
270                         { $$ = newLOGOP($2, 0, $1, $3); }
271         |       NOTOP expr
272                         { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
273         |       argexpr
274         ;
275
276 argexpr :       argexpr ','
277                         { $$ = $1; }
278         |       argexpr ',' term
279                         { $$ = append_elem(OP_LIST, $1, $3); }
280         |       term
281         ;
282
283 listop  :       LSTOP indirob argexpr
284                         { $$ = convert($1, OPf_STACKED,
285                                 prepend_elem(OP_LIST, newGVREF($1,$2), $3) ); }
286         |       FUNC '(' indirob expr ')'
287                         { $$ = convert($1, OPf_STACKED,
288                                 prepend_elem(OP_LIST, newGVREF($1,$3), $4) ); }
289         |       term ARROW method '(' listexprcom ')'
290                         { $$ = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL,
291                                 append_elem(OP_LIST,
292                                     prepend_elem(OP_LIST, $1, list($5)),
293                                     newUNOP(OP_METHOD, 0, $3))); }
294         |       METHOD indirob listexpr
295                         { $$ = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL,
296                                 append_elem(OP_LIST,
297                                     prepend_elem(OP_LIST, $2, list($3)),
298                                     newUNOP(OP_METHOD, 0, $1))); }
299         |       FUNCMETH indirob '(' listexprcom ')'
300                         { $$ = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL,
301                                 append_elem(OP_LIST,
302                                     prepend_elem(OP_LIST, $2, list($4)),
303                                     newUNOP(OP_METHOD, 0, $1))); }
304         |       LSTOP listexpr
305                         { $$ = convert($1, 0, $2); }
306         |       FUNC '(' listexprcom ')'
307                         { $$ = convert($1, 0, $3); }
308         ;
309
310 method  :       METHOD
311         |       scalar
312         ;
313
314 term    :       term ASSIGNOP term
315                         { $$ = newASSIGNOP(OPf_STACKED, $1, $2, $3); }
316         |       term POWOP term
317                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
318         |       term MULOP term
319                         {   if ($2 != OP_REPEAT)
320                                 scalar($1);
321                             $$ = newBINOP($2, 0, $1, scalar($3)); }
322         |       term ADDOP term
323                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
324         |       term SHIFTOP term
325                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
326         |       term RELOP term
327                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
328         |       term EQOP term
329                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
330         |       term BITANDOP term
331                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
332         |       term BITOROP term
333                         { $$ = newBINOP($2, 0, scalar($1), scalar($3)); }
334         |       term DOTDOT term
335                         { $$ = newRANGE($2, scalar($1), scalar($3));}
336         |       term ANDAND term
337                         { $$ = newLOGOP(OP_AND, 0, $1, $3); }
338         |       term OROR term
339                         { $$ = newLOGOP(OP_OR, 0, $1, $3); }
340         |       term '?' term ':' term
341                         { $$ = newCONDOP(0, $1, $3, $5); }
342         |       term MATCHOP term
343                         { $$ = bind_match($2, $1, $3); }
344
345         |       '-' term %prec UMINUS
346                         { $$ = newUNOP(OP_NEGATE, 0, scalar($2)); }
347         |       '+' term %prec UMINUS
348                         { $$ = $2; }
349         |       '!' term
350                         { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
351         |       '~' term
352                         { $$ = newUNOP(OP_COMPLEMENT, 0, scalar($2));}
353         |       REFGEN term
354                         { $$ = newUNOP(OP_REFGEN, 0, mod($2,OP_REFGEN)); }
355         |       term POSTINC
356                         { $$ = newUNOP(OP_POSTINC, 0,
357                                         mod(scalar($1), OP_POSTINC)); }
358         |       term POSTDEC
359                         { $$ = newUNOP(OP_POSTDEC, 0,
360                                         mod(scalar($1), OP_POSTDEC)); }
361         |       PREINC term
362                         { $$ = newUNOP(OP_PREINC, 0,
363                                         mod(scalar($2), OP_PREINC)); }
364         |       PREDEC term
365                         { $$ = newUNOP(OP_PREDEC, 0,
366                                         mod(scalar($2), OP_PREDEC)); }
367         |       LOCAL term      %prec UNIOP
368                         { $$ = localize($2,$1); }
369         |       '(' expr ')'
370                         { $$ = sawparens($2); }
371         |       '(' ')'
372                         { $$ = sawparens(newNULLLIST()); }
373         |       '[' expr ']'                            %prec '('
374                         { $$ = newANONLIST($2); }
375         |       '[' ']'                                 %prec '('
376                         { $$ = newANONLIST(Nullop); }
377         |       HASHBRACK expr ';' '}'                  %prec '('
378                         { $$ = newANONHASH($2); }
379         |       HASHBRACK ';' '}'                               %prec '('
380                         { $$ = newANONHASH(Nullop); }
381         |       ANONSUB startsub block                          %prec '('
382                         { $$ = newANONSUB($2, $3); }
383         |       scalar  %prec '('
384                         { $$ = $1; }
385         |       star    %prec '('
386                         { $$ = $1; }
387         |       scalar '[' expr ']'     %prec '('
388                         { $$ = newBINOP(OP_AELEM, 0, oopsAV($1), scalar($3)); }
389         |       term ARROW '[' expr ']' %prec '('
390                         { $$ = newBINOP(OP_AELEM, 0,
391                                         ref(newAVREF($1),OP_RV2AV),
392                                         scalar($4));}
393         |       term '[' expr ']'       %prec '('
394                         { assertref($1); $$ = newBINOP(OP_AELEM, 0,
395                                         ref(newAVREF($1),OP_RV2AV),
396                                         scalar($3));}
397         |       hsh     %prec '('
398                         { $$ = $1; }
399         |       ary     %prec '('
400                         { $$ = $1; }
401         |       arylen  %prec '('
402                         { $$ = newUNOP(OP_AV2ARYLEN, 0, ref($1, OP_AV2ARYLEN));}
403         |       scalar '{' expr ';' '}' %prec '('
404                         { $$ = newBINOP(OP_HELEM, 0, oopsHV($1), jmaybe($3));
405                             expect = XOPERATOR; }
406         |       term ARROW '{' expr ';' '}'     %prec '('
407                         { $$ = newBINOP(OP_HELEM, 0,
408                                         ref(newHVREF($1),OP_RV2HV),
409                                         jmaybe($4));
410                             expect = XOPERATOR; }
411         |       term '{' expr ';' '}'   %prec '('
412                         { assertref($1); $$ = newBINOP(OP_HELEM, 0,
413                                         ref(newHVREF($1),OP_RV2HV),
414                                         jmaybe($3));
415                             expect = XOPERATOR; }
416         |       '(' expr ')' '[' expr ']'       %prec '('
417                         { $$ = newSLICEOP(0, $5, $2); }
418         |       '(' ')' '[' expr ']'    %prec '('
419                         { $$ = newSLICEOP(0, $4, Nullop); }
420         |       ary '[' expr ']'        %prec '('
421                         { $$ = prepend_elem(OP_ASLICE,
422                                 newOP(OP_PUSHMARK, 0),
423                                     newLISTOP(OP_ASLICE, 0,
424                                         list($3),
425                                         ref($1, OP_ASLICE))); }
426         |       ary '{' expr ';' '}'    %prec '('
427                         { $$ = prepend_elem(OP_HSLICE,
428                                 newOP(OP_PUSHMARK, 0),
429                                     newLISTOP(OP_HSLICE, 0,
430                                         list($3),
431                                         ref(oopsHV($1), OP_HSLICE)));
432                             expect = XOPERATOR; }
433         |       THING   %prec '('
434                         { $$ = $1; }
435         |       amper
436                         { $$ = newUNOP(OP_ENTERSUB, 0,
437                                 scalar($1)); }
438         |       amper '(' ')'
439                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED, scalar($1)); }
440         |       amper '(' expr ')'
441                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
442                             list(append_elem(OP_LIST, $3, scalar($1)))); }
443         |       NOAMP WORD listexpr
444                         { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
445                             list(append_elem(OP_LIST,
446                                 $3, newCVREF(scalar($2))))); }
447         |       DO term %prec UNIOP
448                         { $$ = newUNOP(OP_DOFILE, 0, scalar($2)); }
449         |       DO block        %prec '('
450                         { $$ = newUNOP(OP_NULL, OPf_SPECIAL, scope($2)); }
451         |       DO WORD '(' ')'
452                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
453                             list(prepend_elem(OP_LIST,
454                                 scalar(newCVREF(scalar($2))), Nullop))); dep();}
455         |       DO WORD '(' expr ')'
456                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
457                             list(append_elem(OP_LIST,
458                                 $4,
459                                 scalar(newCVREF(scalar($2)))))); dep();}
460         |       DO scalar '(' ')'
461                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
462                             list(prepend_elem(OP_LIST,
463                                 scalar(newCVREF(scalar($2))), Nullop))); dep();}
464         |       DO scalar '(' expr ')'
465                         { $$ = newUNOP(OP_ENTERSUB, OPf_SPECIAL|OPf_STACKED,
466                             list(prepend_elem(OP_LIST,
467                                 $4,
468                                 scalar(newCVREF(scalar($2)))))); dep();}
469         |       LOOPEX
470                         { $$ = newOP($1, OPf_SPECIAL);
471                             hints |= HINT_BLOCK_SCOPE; }
472         |       LOOPEX term
473                         { $$ = newLOOPEX($1,$2); }
474         |       UNIOP
475                         { $$ = newOP($1, 0); }
476         |       UNIOP block
477                         { $$ = newUNOP($1, 0, $2); }
478         |       UNIOP term
479                         { $$ = newUNOP($1, 0, $2); }
480         |       FUNC0
481                         { $$ = newOP($1, 0); }
482         |       FUNC0 '(' ')'
483                         { $$ = newOP($1, 0); }
484         |       FUNC1 '(' ')'
485                         { $$ = newOP($1, OPf_SPECIAL); }
486         |       FUNC1 '(' expr ')'
487                         { $$ = newUNOP($1, 0, $3); }
488         |       PMFUNC '(' term ')'
489                         { $$ = pmruntime($1, $3, Nullop); }
490         |       PMFUNC '(' term ',' term ')'
491                         { $$ = pmruntime($1, $3, $5); }
492         |       WORD
493         |       listop
494         ;
495
496 listexpr:       /* NULL */
497                         { $$ = Nullop; }
498         |       argexpr
499                         { $$ = $1; }
500         ;
501
502 listexprcom:    /* NULL */
503                         { $$ = Nullop; }
504         |       expr
505                         { $$ = $1; }
506         |       expr ','
507                         { $$ = $1; }
508         ;
509
510 amper   :       '&' indirob
511                         { $$ = newCVREF($2); }
512         ;
513
514 scalar  :       '$' indirob
515                         { $$ = newSVREF($2); }
516         ;
517
518 ary     :       '@' indirob
519                         { $$ = newAVREF($2); }
520         ;
521
522 hsh     :       '%' indirob
523                         { $$ = newHVREF($2); }
524         ;
525
526 arylen  :       DOLSHARP indirob
527                         { $$ = newAVREF($2); }
528         ;
529
530 star    :       '*' indirob
531                         { $$ = newGVREF(0,$2); }
532         ;
533
534 indirob :       WORD
535                         { $$ = scalar($1); }
536         |       scalar
537                         { $$ = scalar($1);  }
538         |       block
539                         { $$ = scope($1); }
540
541         |       PRIVATEREF
542                         { $$ = $1; }
543         ;
544
545 %% /* PROGRAM */