1 /**************************************************************************
4 * Author: Maria M. Gutierrez *
5 * Modified by: Kevin Hammond *
6 * Last date revised: December 13 1991. KH. *
7 * Modification: Haskell 1.1 Syntax. *
10 * Description: This file contains the LALR(1) grammar for Haskell. *
12 * Entry Point: module *
14 * Problems: None known. *
17 * LALR(1) Syntax for Haskell 1.2 *
19 **************************************************************************/
31 #include "constants.h"
34 /**********************************************************************
37 * Imported Variables and Functions *
40 **********************************************************************/
42 static BOOLEAN expect_ccurly = FALSE; /* Used to signal that a CCURLY could be inserted here */
45 extern char *input_filename;
46 static char *the_module_name;
47 static maybe module_exports;
50 extern list reverse_list();
53 /* For FN, PREVPATT and SAMEFN macros */
55 extern BOOLEAN samefn[];
56 extern tree prevpatt[];
57 extern short icontexts;
60 extern int hsplineno, hspcolno;
61 extern int modulelineno;
62 extern int startlineno;
65 /**********************************************************************
68 * Fixity and Precedence Declarations *
71 **********************************************************************/
73 static int Fixity = 0, Precedence = 0;
75 char *ineg PROTO((char *));
77 long source_version = 0;
78 BOOLEAN pat_check=TRUE;
102 /**********************************************************************
105 * These are lexemes. *
108 **********************************************************************/
111 %token VARID CONID QVARID QCONID
112 VARSYM CONSYM QVARSYM QCONSYM
114 %token INTEGER FLOAT CHAR STRING
115 CHARPRIM STRINGPRIM INTPRIM FLOATPRIM
120 /**********************************************************************
126 **********************************************************************/
128 %token OCURLY CCURLY VCCURLY
129 %token COMMA SEMI OBRACK CBRACK
130 %token WILDCARD BQUOTE OPAREN CPAREN
133 /**********************************************************************
136 * Reserved Operators *
139 **********************************************************************/
141 %token DOTDOT DCOLON EQUAL LAMBDA
142 %token VBAR RARROW LARROW
143 %token AT LAZY DARROW
146 /**********************************************************************
149 * Reserved Identifiers *
152 **********************************************************************/
154 %token CASE CLASS DATA
155 %token DEFAULT DERIVING DO
156 %token ELSE IF IMPORT
157 %token IN INFIX INFIXL
158 %token INFIXR INSTANCE LET
159 %token MODULE NEWTYPE OF
160 %token THEN TYPE WHERE
163 %token CCALL CCALL_GC CASM CASM_GC
164 %token EXPORT UNSAFE STDCALL C_CALL
165 %token PASCAL FASTCALL FOREIGN DYNAMIC
167 /**********************************************************************
170 * Special symbols/identifiers which need to be recognised *
173 **********************************************************************/
175 %token MINUS BANG PLUS
176 %token AS HIDING QUALIFIED
179 /**********************************************************************
182 * Special Symbols for the Lexer *
185 **********************************************************************/
187 %token INTERFACE_UPRAGMA SPECIALISE_UPRAGMA
188 %token INLINE_UPRAGMA NOINLINE_UPRAGMA MAGIC_UNFOLDING_UPRAGMA
190 %token SOURCE_UPRAGMA
192 /**********************************************************************
195 * Precedences of the various tokens *
198 **********************************************************************/
203 SCC CASM CCALL CASM_GC CCALL_GC
205 %left VARSYM CONSYM QVARSYM QCONSYM
206 MINUS BQUOTE BANG DARROW PLUS
212 %left OCURLY OBRACK OPAREN
218 /**********************************************************************
221 * Type Declarations *
224 **********************************************************************/
227 %type <ulist> caserest alts alt quals
229 rbinds rbinds1 rpats rpats1 list_exps list_rest
231 constrs constr1 fields
234 pats simple_context simple_context_list
237 impdecls maybeimpdecls impdecl
238 maybefixes fixes fix ops
243 %type <umaybe> maybeexports impspec deriving
246 %type <uliteral> lit_constant
248 %type <utree> exp oexp dexp kexp fexp aexp rbind texps
249 expL oexpL kexpL expLno oexpLno dexpLno kexpLno
250 vallhs funlhs qual leftexp
251 pat cpat bpat apat apatc conpat rpat
252 patk bpatk apatck conpatk
255 %type <uid> MINUS PLUS DARROW AS LAZY
256 VARID CONID VARSYM CONSYM
257 var con varop conop op
258 vark varid varsym varsym_nominus
261 %type <uqid> QVARID QCONID QVARSYM QCONSYM
262 qvarid qconid qvarsym qconsym
263 qvar qcon qvarop qconop qop
264 qvark qconk qtycon qtycls
265 gcon gconk gtycon itycon qop1 qvarop1
268 %type <ubinding> topdecl topdecls letdecls
269 typed datad newtd classd instd defaultd foreignd
270 decl decls valdef instdef instdefs
271 maybe_where cbody rinst type_and_maybe_id
273 %type <upbinding> valrhs1 altrest
275 %type <uttype> ctype sigtype sigarrowtype type atype bigatype btype
276 bbtype batype bxtype wierd_atype
277 simple_con_app simple_con_app1 tyvar contype inst_type
279 %type <uconstr> constr constr_after_context field
281 %type <ustring> FLOAT INTEGER INTPRIM
282 FLOATPRIM DOUBLEPRIM CLITLIT
284 %type <uhstring> STRING STRINGPRIM CHAR CHARPRIM
286 %type <uentid> export import
288 %type <ulong> commas importkey get_line_no
291 /**********************************************************************
294 * Start Symbol for the Parser *
297 **********************************************************************/
302 module : modulekey modid maybeexports
304 modulelineno = startlineno;
305 the_module_name = $2;
311 the_module_name = install_literal("Main");
312 module_exports = mknothing();
317 body : ocurly { setstartlineno(); } interface_pragma orestm
318 | vocurly interface_pragma vrestm
321 interface_pragma : /* empty */
322 | INTERFACE_UPRAGMA INTEGER END_UPRAGMA SEMI
324 source_version = atoi($2);
328 orestm : maybeimpdecls maybefixes topdecls ccurly
330 root = mkhmodule(the_module_name,$1,module_exports,
331 $2,$3,source_version,modulelineno);
335 root = mkhmodule(the_module_name,$1,module_exports,
336 Lnil,mknullbind(),source_version,modulelineno);
339 vrestm : maybeimpdecls maybefixes topdecls vccurly
341 root = mkhmodule(the_module_name,$1,module_exports,
342 $2,$3,source_version,modulelineno);
346 root = mkhmodule(the_module_name,$1,module_exports,
347 Lnil,mknullbind(),source_version,modulelineno);
350 maybeexports : /* empty */ { $$ = mknothing(); }
351 | OPAREN export_list CPAREN { $$ = mkjust($2); }
352 | OPAREN export_list COMMA CPAREN { $$ = mkjust($2); }
356 export { $$ = lsing($1); }
357 | export_list COMMA export { $$ = lapp($1, $3); }
360 export : qvar { $$ = mkentid($1); }
361 | gtycon { $$ = mkenttype($1); }
362 | gtycon OPAREN DOTDOT CPAREN { $$ = mkenttypeall($1); }
363 | gtycon OPAREN CPAREN { $$ = mkenttypenamed($1,Lnil); }
364 | gtycon OPAREN enames CPAREN { $$ = mkenttypenamed($1,$3); }
365 | MODULE modid { $$ = mkentmod($2); }
368 enames : ename { $$ = lsing($1); }
369 | enames COMMA ename { $$ = lapp($1,$3); }
376 maybeimpdecls : /* empty */ { $$ = Lnil; }
377 | impdecls SEMI { $$ = $1; }
380 impdecls: impdecl { $$ = $1; }
381 | impdecls SEMI impdecl { $$ = lconc($1,$3); }
385 impdecl : importkey modid impspec
386 { $$ = lsing(mkimport($2,0,mknothing(),$3,$1,startlineno)); }
387 | importkey QUALIFIED modid impspec
388 { $$ = lsing(mkimport($3,1,mknothing(),$4,$1,startlineno)); }
389 | importkey QUALIFIED modid AS modid impspec
390 { $$ = lsing(mkimport($3,1,mkjust($5),$6,$1,startlineno)); }
391 | importkey modid AS modid impspec
392 { $$ = lsing(mkimport($3,1,mkjust($4),$5,$1,startlineno)); }
395 impspec : /* empty */ { $$ = mknothing(); }
396 | OPAREN CPAREN { $$ = mkjust(mkleft(Lnil)); }
397 | OPAREN import_list CPAREN { $$ = mkjust(mkleft($2)); }
398 | OPAREN import_list COMMA CPAREN { $$ = mkjust(mkleft($2)); }
399 | HIDING OPAREN import_list CPAREN { $$ = mkjust(mkright($3)); }
400 | HIDING OPAREN import_list COMMA CPAREN { $$ = mkjust(mkright($3)); }
404 import { $$ = lsing($1); }
405 | import_list COMMA import { $$ = lapp($1, $3); }
408 import : var { $$ = mkentid(mknoqual($1)); }
409 | itycon { $$ = mkenttype($1); }
410 | itycon OPAREN DOTDOT CPAREN { $$ = mkenttypeall($1); }
411 | itycon OPAREN CPAREN { $$ = mkenttypenamed($1,Lnil);}
412 | itycon OPAREN inames CPAREN { $$ = mkenttypenamed($1,$3); }
415 itycon : tycon { $$ = mknoqual($1); }
416 | OBRACK CBRACK { $$ = creategid(NILGID); }
417 | OPAREN CPAREN { $$ = creategid(UNITGID); }
418 | OPAREN commas CPAREN { $$ = creategid($2); }
421 inames : iname { $$ = lsing($1); }
422 | inames COMMA iname { $$ = lapp($1,$3); }
424 iname : var { $$ = mknoqual($1); }
425 | con { $$ = mknoqual($1); }
428 /**********************************************************************
431 * Fixes and Decls etc *
434 **********************************************************************/
436 maybefixes: /* empty */ { $$ = Lnil; }
437 | fixes SEMI { $$ = $1; }
440 fixes : fix { $$ = $1; }
441 | fixes SEMI fix { $$ = lconc($1,$3); }
444 fix : INFIXL INTEGER { Precedence = checkfixity($2); Fixity = INFIXL; }
446 | INFIXR INTEGER { Precedence = checkfixity($2); Fixity = INFIXR; }
448 | INFIX INTEGER { Precedence = checkfixity($2); Fixity = INFIX; }
450 | INFIXL { Fixity = INFIXL; Precedence = 9; }
452 | INFIXR { Fixity = INFIXR; Precedence = 9; }
454 | INFIX { Fixity = INFIX; Precedence = 9; }
458 ops : op { $$ = lsing(mkfixop(mknoqual($1),infixint(Fixity),Precedence,startlineno)); }
459 | ops COMMA op { $$ = lapp($1,mkfixop(mknoqual($3),infixint(Fixity),Precedence,startlineno)); }
463 | topdecls SEMI topdecl
482 topdecl : typed { $$ = $1; FN = NULL; SAMEFN = 0; }
483 | datad { $$ = $1; FN = NULL; SAMEFN = 0; }
484 | newtd { $$ = $1; FN = NULL; SAMEFN = 0; }
485 | classd { $$ = $1; FN = NULL; SAMEFN = 0; }
486 | instd { $$ = $1; FN = NULL; SAMEFN = 0; }
487 | defaultd { $$ = $1; FN = NULL; SAMEFN = 0; }
488 | foreignd { $$ = $1; FN = NULL; SAMEFN = 0; }
492 typed : typekey simple_con_app EQUAL type { $$ = mknbind($2,$4,startlineno); }
496 datad : datakey simple_con_app EQUAL constrs deriving
497 { $$ = mktbind(Lnil,$2,$4,$5,startlineno); }
498 | datakey simple_context DARROW simple_con_app EQUAL constrs deriving
499 { $$ = mktbind($2,$4,$6,$7,startlineno); }
502 newtd : newtypekey simple_con_app EQUAL constr1 deriving
503 { $$ = mkntbind(Lnil,$2,$4,$5,startlineno); }
504 | newtypekey simple_context DARROW simple_con_app EQUAL constr1 deriving
505 { $$ = mkntbind($2,$4,$6,$7,startlineno); }
508 deriving: /* empty */ { $$ = mknothing(); }
509 | DERIVING dtyclses { $$ = mkjust($2); }
512 classd : classkey btype DARROW simple_con_app1 cbody
513 /* Context can now be more than simple_context */
514 { $$ = mkcbind(type2context($2),$4,$5,startlineno); }
515 | classkey btype cbody
516 /* We have to say btype rather than simple_con_app1, else
517 we get reduce/reduce errs */
518 { check_class_decl_head($2);
519 $$ = mkcbind(Lnil,$2,$3,startlineno); }
522 cbody : /* empty */ { $$ = mknullbind(); }
523 | WHERE ocurly decls ccurly { checkorder($3); $$ = $3; }
524 | WHERE vocurly decls vccurly { checkorder($3); $$ = $3; }
527 instd : instkey inst_type rinst { $$ = mkibind($2,$3,startlineno); }
531 inst_type : type DARROW type { is_context_format( $3, 0 ); /* Check the instance head */
532 $$ = mkcontext(type2context($1),$3); }
533 | btype { is_context_format( $1, 0 ); /* Check the instance head */
538 rinst : /* empty */ { $$ = mknullbind(); }
539 | WHERE ocurly instdefs ccurly { $$ = $3; }
540 | WHERE vocurly instdefs vccurly { $$ = $3; }
543 defaultd: defaultkey OPAREN types CPAREN { $$ = mkdbind($3,startlineno); }
544 | defaultkey OPAREN CPAREN { $$ = mkdbind(Lnil,startlineno); }
547 /* FFI primitive declarations - GHC/Hugs specific */
548 foreignd: foreignkey IMPORT callconv ext_name unsafe_flag qvarid DCOLON sigtype { $$ = mkfobind($6,$8,$4,$5,$3,FOREIGN_IMPORT,startlineno); }
549 | foreignkey EXPORT callconv ext_name qvarid DCOLON sigtype { $$ = mkfobind($5,$7,$4,0,$3,FOREIGN_EXPORT,startlineno); }
552 callconv: STDCALL { $$ = CALLCONV_STDCALL; }
553 | C_CALL { $$ = CALLCONV_CCALL; }
554 | PASCAL { $$ = CALLCONV_PASCAL; }
555 | FASTCALL { $$ = CALLCONV_FASTCALL; }
558 ext_name: STRING { $$ = mkjust(lsing($1)); }
559 | STRING STRING { $$ = mkjust(mklcons ($1,lsing($2))); }
560 | DYNAMIC { $$ = mknothing(); }
562 unsafe_flag: UNSAFE { $$ = 1; }
563 | /*empty*/ { $$ = 0; }
582 Note: if there is an iclasop_pragma here, then we must be
583 doing a class-op in an interface -- unless the user is up
584 to real mischief (ugly, but likely to work).
587 decl : qvarsk DCOLON sigtype
588 { $$ = mksbind($1,$3,startlineno);
589 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
592 /* User-specified pragmas come in as "signatures"...
593 They are similar in that they can appear anywhere in the module,
594 and have to be "joined up" with their related entity.
596 Have left out the case specialising to an overloaded type.
597 Let's get real, OK? (WDP)
599 | SPECIALISE_UPRAGMA qvark DCOLON types_and_maybe_ids END_UPRAGMA
601 $$ = mkvspec_uprag($2, $4, startlineno);
602 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
605 | SPECIALISE_UPRAGMA INSTANCE gtycon atype END_UPRAGMA
607 $$ = mkispec_uprag($3, $4, startlineno);
608 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
611 | SPECIALISE_UPRAGMA DATA gtycon atypes END_UPRAGMA
613 $$ = mkdspec_uprag($3, $4, startlineno);
614 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
617 | INLINE_UPRAGMA qvark END_UPRAGMA
619 $$ = mkinline_uprag($2, startlineno);
620 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
623 | NOINLINE_UPRAGMA qvark END_UPRAGMA
625 $$ = mknoinline_uprag($2, startlineno);
626 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
629 | MAGIC_UNFOLDING_UPRAGMA qvark vark END_UPRAGMA
631 $$ = mkmagicuf_uprag($2, $3, startlineno);
632 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
635 /* end of user-specified pragmas */
638 | /* empty */ { $$ = mknullbind(); PREVPATT = NULL; FN = NULL; SAMEFN = 0; }
641 qvarsk : qvark COMMA qvars_list { $$ = mklcons($1,$3); }
642 | qvark { $$ = lsing($1); }
645 qvars_list: qvar { $$ = lsing($1); }
646 | qvars_list COMMA qvar { $$ = lapp($1,$3); }
649 types_and_maybe_ids :
650 type_and_maybe_id { $$ = lsing($1); }
651 | types_and_maybe_ids COMMA type_and_maybe_id { $$ = lapp($1,$3); }
655 type { $$ = mkvspec_ty_and_id($1,mknothing()); }
656 | type EQUAL qvark { $$ = mkvspec_ty_and_id($1,mkjust($3)); }
659 /**********************************************************************
665 **********************************************************************/
667 /* "DCOLON context => type" vs "DCOLON type" is a problem,
668 because you can't distinguish between
670 foo :: (Baz a, Baz a)
671 bar :: (Baz a, Baz a) => [a] -> [a] -> [a]
673 with one token of lookahead. The HACK is to have "DCOLON ttype"
674 [tuple type] in the first case, then check that it has the right
675 form C a, or (C1 a, C2 b, ... Cn z) and convert it into a
679 /* A sigtype is a rank 2 type; it can have for-alls as function args:
680 f :: All a => (All b => ...) -> Int
682 sigtype : btype DARROW sigarrowtype { $$ = mkcontext(type2context($1),$3); }
686 sigarrowtype : bigatype RARROW sigarrowtype { $$ = mktfun($1,$3); }
687 | btype RARROW sigarrowtype { $$ = mktfun($1,$3); }
691 /* A "big" atype can be a forall-type in brackets. */
692 bigatype: OPAREN btype DARROW type CPAREN { $$ = mkcontext(type2context($2),$4); }
695 /* 1 S/R conflict at DARROW -> shift */
696 ctype : btype DARROW type { $$ = mkcontext(type2context($1),$3); }
700 /* 1 S/R conflict at RARROW -> shift */
701 type : btype RARROW type { $$ = mktfun($1,$3); }
705 btype : btype atype { $$ = mktapp($1,$2); }
709 atype : gtycon { $$ = mktname($1); }
711 | OPAREN type COMMA types CPAREN { $$ = mkttuple(mklcons($2,$4)); }
712 | OBRACK type CBRACK { $$ = mktllist($2); }
713 | OPAREN type CPAREN { $$ = $2; }
717 | OPAREN RARROW CPAREN { $$ = creategid(ARROWGID); }
718 | OBRACK CBRACK { $$ = creategid(NILGID); }
719 | OPAREN CPAREN { $$ = creategid(UNITGID); }
720 | OPAREN commas CPAREN { $$ = creategid($2); }
723 atypes : atype { $$ = lsing($1); }
724 | atypes atype { $$ = lapp($1,$2); }
727 types : type { $$ = lsing($1); }
728 | types COMMA type { $$ = lapp($1,$3); }
731 commas : COMMA { $$ = 1; }
732 | commas COMMA { $$ = $1 + 1; }
735 /**********************************************************************
738 * Declaration stuff *
741 **********************************************************************/
743 /* C a b c, where a,b,c are type variables */
744 /* C can be a class or tycon */
745 simple_con_app: gtycon { $$ = mktname($1); }
746 | simple_con_app1 { $$ = $1; }
749 simple_con_app1: gtycon tyvar { $$ = mktapp(mktname($1),$2); }
750 | simple_con_app tyvar { $$ = mktapp($1, $2); }
753 simple_context : OPAREN simple_context_list CPAREN { $$ = $2; }
754 | simple_con_app1 { $$ = lsing($1); }
757 simple_context_list: simple_con_app1 { $$ = lsing($1); }
758 | simple_context_list COMMA simple_con_app1 { $$ = lapp($1,$3); }
761 constrs : constr { $$ = lsing($1); }
762 | constrs VBAR constr { $$ = lapp($1,$3); }
765 constr : constr_after_context
766 | btype DARROW constr_after_context { $$ = mkconstrcxt ( type2context($1), $3 ); }
769 constr_after_context :
771 /* We have to parse the constructor application as a *type*, else we get
772 into terrible ambiguity problems. Consider the difference between
774 data T = S Int Int Int `R` Int
776 data T = S Int Int Int
778 It isn't till we get to the operator that we discover that the "S" is
779 part of a type in the first, but part of a constructor application in the
783 /* Con !Int (Tree a) */
784 contype { qid tyc; list tys;
785 splittyconapp($1, &tyc, &tys);
786 $$ = mkconstrpre(tyc,tys,hsplineno); }
788 /* !Int `Con` Tree a */
789 | bbtype qconop bbtype { $$ = mkconstrinf($1,$2,$3,hsplineno); }
791 /* (::) (Tree a) Int */
792 | OPAREN qconsym CPAREN batypes { $$ = mkconstrpre($2,$4,hsplineno); }
794 /* Con { op1 :: Int } */
795 | qtycon OCURLY fields CCURLY { $$ = mkconstrrec($1,$3,hsplineno); }
796 | OPAREN qconsym CPAREN OCURLY fields CCURLY { $$ = mkconstrrec($2,$5,hsplineno); }
798 /* 1 S/R conflict on OCURLY -> shift */
801 /* contype has to reduce to a btype unless there are !'s, so that
802 we don't get reduce/reduce conflicts with the second production of constr.
803 But as soon as we see a ! we must switch to using bxtype. */
805 contype : btype { $$ = $1; }
806 | bxtype { $$ = $1; }
809 /* S !Int Bool; at least one ! */
810 bxtype : btype wierd_atype { $$ = mktapp($1, $2); }
811 | bxtype batype { $$ = mktapp($1, $2); }
814 bbtype : btype { $$ = $1; }
815 | wierd_atype { $$ = $1; }
818 batype : atype { $$ = $1; }
819 | wierd_atype { $$ = $1; }
822 /* A wierd atype is one that isn't a regular atype;
823 it starts with a "!", or with a forall. */
824 wierd_atype : BANG bigatype { $$ = mktbang( $2 ); }
825 | BANG atype { $$ = mktbang( $2 ); }
829 batypes : { $$ = Lnil; }
830 | batypes batype { $$ = lapp($1,$2); }
834 fields : field { $$ = lsing($1); }
835 | fields COMMA field { $$ = lapp($1,$3); }
838 field : qvars_list DCOLON ctype { $$ = mkfield($1,$3); }
839 | qvars_list DCOLON BANG atype { $$ = mkfield($1,mktbang($4)); }
840 | qvars_list DCOLON BANG bigatype { $$ = mkfield($1,mktbang($4)); }
843 constr1 : gtycon atype { $$ = lsing(mkconstrnew($1,$2,hsplineno)); }
847 dtyclses: OPAREN dtycls_list CPAREN { $$ = $2; }
848 | OPAREN CPAREN { $$ = Lnil; }
849 | qtycls { $$ = lsing($1); }
852 dtycls_list: qtycls { $$ = lsing($1); }
853 | dtycls_list COMMA qtycls { $$ = lapp($1,$3); }
856 instdefs : /* empty */ { $$ = mknullbind(); }
857 | instdef { $$ = $1; }
858 | instdefs SEMI instdef
870 /* instdef: same as valdef, except certain user-pragmas may appear */
872 SPECIALISE_UPRAGMA qvark DCOLON types_and_maybe_ids END_UPRAGMA
874 $$ = mkvspec_uprag($2, $4, startlineno);
875 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
878 | INLINE_UPRAGMA qvark END_UPRAGMA
880 $$ = mkinline_uprag($2, startlineno);
881 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
884 | NOINLINE_UPRAGMA qvark END_UPRAGMA
886 $$ = mknoinline_uprag($2, startlineno);
887 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
890 | MAGIC_UNFOLDING_UPRAGMA qvark vark END_UPRAGMA
892 $$ = mkmagicuf_uprag($2, $3, startlineno);
893 PREVPATT = NULL; FN = NULL; SAMEFN = 0;
903 tree fn = function($1);
906 if(ttree(fn) == ident)
908 qid fun_id = gident((struct Sident *) fn);
913 else if (ttree(fn) == infixap)
915 qid fun_id = ginffun((struct Sinfixap *) fn);
922 printf("%u\n",startlineno);
924 fprintf(stderr,"%u\tvaldef\n",startlineno);
931 if ( lhs_is_patt($1) )
933 $$ = mkpbind($4, $3);
938 $$ = mkfbind($4, $3);
944 get_line_no : { $$ = startlineno; }
947 vallhs : patk { $$ = $1; }
948 | patk qvarop pat { $$ = mkinfixap($2,$1,$3); }
949 | funlhs { $$ = $1; }
952 funlhs : qvark apat { $$ = mkap(mkident($1),$2); }
953 | funlhs apat { $$ = mkap($1,$2); }
957 valrhs : valrhs1 maybe_where { $$ = lsing(createpat($1, $2)); }
960 valrhs1 : gdrhs { $$ = mkpguards($1); }
961 | EQUAL exp { $$ = mkpnoguards($2); }
964 gdrhs : gd EQUAL exp { $$ = lsing(mkpgdexp($1,$3)); }
965 | gd EQUAL exp gdrhs { $$ = mklcons(mkpgdexp($1,$3),$4); }
969 WHERE ocurly decls ccurly { $$ = $3; }
970 | WHERE vocurly decls vccurly { $$ = $3; }
971 /* A where containing no decls is OK */
972 | WHERE SEMI { $$ = mknullbind(); }
973 | /* empty */ { $$ = mknullbind(); }
976 gd : VBAR quals { $$ = $2; }
980 /**********************************************************************
986 **********************************************************************/
988 exp : oexp DCOLON ctype { $$ = mkrestr($1,$3); }
993 Operators must be left-associative at the same precedence for
994 precedence parsing to work.
996 /* 8 S/R conflicts on qop -> shift */
997 oexp : oexp qop oexp %prec MINUS { $$ = mkinfixap($2,$1,$3); }
1002 This comes here because of the funny precedence rules concerning
1005 dexp : MINUS kexp { $$ = mknegate($2); }
1010 We need to factor out a leading let expression so we can set
1011 pat_check=FALSE when parsing (non let) expressions inside stmts and quals
1013 expLno : oexpLno DCOLON ctype { $$ = mkrestr($1,$3); }
1016 oexpLno : oexpLno qop oexp %prec MINUS { $$ = mkinfixap($2,$1,$3); }
1019 dexpLno : MINUS kexp { $$ = mknegate($2); }
1023 expL : oexpL DCOLON ctype { $$ = mkrestr($1,$3); }
1026 oexpL : oexpL qop oexp %prec MINUS { $$ = mkinfixap($2,$1,$3); }
1031 let/if/lambda/case have higher precedence than infix operators.
1038 /* kexpL = a let expression */
1039 kexpL : letdecls IN exp { $$ = mklet($1,$3); }
1042 /* kexpLno = any other expression more tightly binding than operator application */
1044 { hsincindent(); /* push new context for FN = NULL; */
1045 FN = NULL; /* not actually concerned about indenting */
1046 $<ulong>$ = hsplineno; /* remember current line number */
1051 RARROW exp /* lambda abstraction */
1053 $$ = mklambda($3, $6, $<ulong>2);
1057 | IF {$<ulong>$ = hsplineno;}
1058 exp THEN exp ELSE exp { $$ = mkife($3,$5,$7,$<ulong>2); }
1060 /* Case Expression */
1061 | CASE {$<ulong>$ = hsplineno;}
1062 exp OF caserest { $$ = mkcasee($3,$5,$<ulong>2); }
1065 | DO {$<ulong>$ = hsplineno;}
1066 dorest { $$ = mkdoe($3,$<ulong>2); }
1068 /* CCALL/CASM Expression */
1069 | CCALL ccallid cexps { $$ = mkccall($2,install_literal("n"),$3); }
1070 | CCALL ccallid { $$ = mkccall($2,install_literal("n"),Lnil); }
1071 | CCALL_GC ccallid cexps { $$ = mkccall($2,install_literal("p"),$3); }
1072 | CCALL_GC ccallid { $$ = mkccall($2,install_literal("p"),Lnil); }
1073 | CASM CLITLIT cexps { $$ = mkccall($2,install_literal("N"),$3); }
1074 | CASM CLITLIT { $$ = mkccall($2,install_literal("N"),Lnil); }
1075 | CASM_GC CLITLIT cexps { $$ = mkccall($2,install_literal("P"),$3); }
1076 | CASM_GC CLITLIT { $$ = mkccall($2,install_literal("P"),Lnil); }
1078 /* SCC Expression */
1083 "\"%s\":%d: _scc_ (`set [profiling] cost centre') ignored\n",
1084 input_filename, hsplineno);
1086 $$ = mkpar($3); /* Note the mkpar(). If we don't have it, then
1087 (x >> _scc_ y >> z) parses as (x >> (y >> z)),
1088 right associated. But the precedence reorganiser expects
1089 the parser to *left* associate all operators unless there
1090 are explicit parens. The _scc_ acts like an explicit paren,
1091 so if we omit it we'd better add explicit parens instead. */
1099 fexp : fexp aexp { $$ = mkap($1,$2); }
1103 /* simple expressions */
1104 aexp : qvar { $$ = mkident($1); }
1105 | gcon { $$ = mkident($1); }
1106 | lit_constant { $$ = mklit($1); }
1107 | OPAREN exp CPAREN { $$ = mkpar($2); } /* mkpar: stop infix parsing at ()'s */
1108 | qcon OCURLY rbinds CCURLY { $$ = mkrecord($1,$3); } /* 1 S/R conflict on OCURLY -> shift */
1109 | OBRACK list_exps CBRACK { $$ = mkllist($2); }
1110 | OPAREN exp COMMA texps CPAREN { if (ttree($4) == tuple)
1111 $$ = mktuple(mklcons($2, gtuplelist((struct Stuple *) $4)));
1113 $$ = mktuple(ldub($2, $4)); }
1115 /* only in expressions ... */
1116 | aexp OCURLY rbinds1 CCURLY { $$ = mkrupdate($1,$3); }
1117 | OBRACK exp VBAR quals CBRACK { $$ = mkcomprh($2,$4); }
1118 | OBRACK exp COMMA exp DOTDOT exp CBRACK {$$= mkeenum($2,mkjust($4),mkjust($6)); }
1119 | OBRACK exp COMMA exp DOTDOT CBRACK { $$ = mkeenum($2,mkjust($4),mknothing()); }
1120 | OBRACK exp DOTDOT exp CBRACK { $$ = mkeenum($2,mknothing(),mkjust($4)); }
1121 | OBRACK exp DOTDOT CBRACK { $$ = mkeenum($2,mknothing(),mknothing()); }
1122 | OPAREN oexp qop CPAREN { $$ = mklsection($2,$3); }
1123 | OPAREN qop1 oexp CPAREN { $$ = mkrsection($2,$3); }
1125 /* only in patterns ... */
1126 /* these add 2 S/R conflict with with aexp . OCURLY rbinds CCURLY */
1127 | qvar AT aexp { checkinpat(); $$ = mkas($1,$3); }
1128 | LAZY aexp { checkinpat(); $$ = mklazyp($2); }
1129 | WILDCARD { checkinpat(); $$ = mkwildp(); }
1132 /* ccall arguments */
1133 cexps : cexps aexp { $$ = lapp($1,$2); }
1134 | aexp { $$ = lsing($1); }
1137 caserest: ocurly alts ccurly { $$ = $2; }
1138 | vocurly alts vccurly { $$ = $2; }
1140 dorest : ocurly stmts ccurly { checkdostmts($2); $$ = $2; }
1141 | vocurly stmts vccurly { checkdostmts($2); $$ = $2; }
1144 rbinds : /* empty */ { $$ = Lnil; }
1148 rbinds1 : rbind { $$ = lsing($1); }
1149 | rbinds1 COMMA rbind { $$ = lapp($1,$3); }
1152 rbind : qvar { $$ = mkrbind($1,mknothing()); }
1153 | qvar EQUAL exp { $$ = mkrbind($1,mkjust($3)); }
1156 texps : exp { $$ = mkpar($1); } /* mkpar: so we don't flatten last element in tuple */
1158 { if (ttree($3) == tuple)
1159 $$ = mktuple(mklcons($1, gtuplelist((struct Stuple *) $3)));
1160 else if (ttree($3) == par)
1161 $$ = mktuple(ldub($1, gpare((struct Spar *) $3)));
1163 hsperror("hsparser:texps: panic");
1165 /* right recursion? WDP */
1169 exp { $$ = lsing($1); }
1170 | exp COMMA exp { $$ = mklcons( $1, lsing($3) ); }
1171 | exp COMMA exp COMMA list_rest { $$ = mklcons( $1, mklcons( $3, reverse_list( $5 ))); }
1174 /* Use left recusion for list_rest, because we sometimes get programs with
1175 very long explicit lists. */
1176 list_rest : exp { $$ = lsing($1); }
1177 | list_rest COMMA exp { $$ = mklcons( $3, $1 ); }
1181 exp { $$ = lsing($1); }
1182 | exp COMMA list_exps { $$ = mklcons($1, $3); }
1184 /* right recursion? (WDP)
1186 It has to be this way, though, otherwise you
1187 may do the wrong thing to distinguish between...
1189 [ e1 , e2 .. ] -- an enumeration ...
1190 [ e1 , e2 , e3 ] -- a list
1192 (In fact, if you change the grammar and throw yacc/bison
1193 at it, it *will* do the wrong thing [WDP 94/06])
1196 letdecls: LET { pat_check = TRUE; } ocurly decls ccurly { $$ = $4; }
1197 | LET { pat_check = TRUE; } vocurly decls vccurly { $$ = $4; }
1201 When parsing patterns inside do stmt blocks or quals, we have
1202 to tentatively parse them as expressions, since we don't know at
1203 the time of parsing `p' whether it will be part of "p <- e" (pat)
1204 or "p" (expr). When we eventually can tell the difference, the parse
1205 of `p' is examined to see if it consitutes a syntactically legal pattern
1208 The expr rule used to parse the pattern/expression do contain
1209 pattern-special productions (e.g., _ , a@pat, etc.), which are
1210 illegal in expressions. Since we don't know whether what
1211 we're parsing is an expression rather than a pattern, we turn off
1212 the check and instead do it later.
1214 The rather clumsy way that this check is turned on/off is there
1215 to work around a Bison feature/shortcoming. Turning the flag
1216 on/off just around the relevant nonterminal by decorating it
1217 with simple semantic actions, e.g.,
1219 {pat_check = FALSE; } expLNo { pat_check = TRUE; }
1221 causes Bison to generate a parser where in one state it either
1222 has to reduce/perform a semantic action ( { pat_check = FALSE; })
1223 or reduce an error (the error production used to implement
1224 vccurly.) Bison picks the semantic action, which it ideally shouldn't.
1225 The work around is to lift out the setting of { pat_check = FALSE; }
1226 and then later reset pat_check. Not pretty.
1231 quals : { pat_check = FALSE;} qual { pat_check = TRUE; $$ = lsing($2); }
1232 | quals COMMA { pat_check = FALSE; } qual { pat_check = TRUE; $$ = lapp($1,$4); }
1235 qual : letdecls { $$ = mkseqlet($1); }
1236 | expL { expORpat(LEGIT_EXPR,$1); $$ = $1; }
1237 | expLno { pat_check = TRUE; } leftexp
1239 expORpat(LEGIT_EXPR,$1);
1242 expORpat(LEGIT_PATT,$1);
1248 alts : alt { $$ = $1; }
1249 | alts SEMI alt { $$ = lconc($1,$3); }
1252 alt : pat { PREVPATT = $1; } altrest { $$ = lsing($3); PREVPATT = NULL; }
1253 | /* empty */ { $$ = Lnil; }
1256 altrest : gdpat maybe_where { $$ = createpat(mkpguards($1), $2); }
1257 | RARROW exp maybe_where { $$ = createpat(mkpnoguards($2),$3); }
1260 gdpat : gd RARROW exp { $$ = lsing(mkpgdexp($1,$3)); }
1261 | gd RARROW exp gdpat { $$ = mklcons(mkpgdexp($1,$3),$4); }
1264 stmts : {pat_check = FALSE;} stmt {pat_check=TRUE; $$ = $2; }
1265 | stmts SEMI {pat_check=FALSE;} stmt {pat_check=TRUE; $$ = lconc($1,$4); }
1268 stmt : /* empty */ { $$ = Lnil; }
1269 | letdecls { $$ = lsing(mkseqlet($1)); }
1270 | expL { expORpat(LEGIT_EXPR,$1); $$ = lsing(mkdoexp($1,hsplineno)); }
1271 | expLno {pat_check=TRUE;} leftexp
1273 expORpat(LEGIT_EXPR,$1);
1274 $$ = lsing(mkdoexp($1,endlineno));
1276 expORpat(LEGIT_PATT,$1);
1277 $$ = lsing(mkdobind($1,$3,endlineno));
1283 leftexp : LARROW exp { $$ = $2; }
1284 | /* empty */ { $$ = NULL; }
1287 /**********************************************************************
1293 **********************************************************************/
1295 pat : qvar PLUS INTEGER { $$ = mkplusp($1, mkinteger($3)); }
1299 cpat : cpat qconop bpat { $$ = mkinfixap($2,$1,$3); }
1305 | qcon OCURLY rpats CCURLY { $$ = mkrecord($1,$3); }
1306 | MINUS INTEGER { $$ = mknegate(mklit(mkinteger($2))); }
1307 | MINUS FLOAT { $$ = mknegate(mklit(mkfloatr($2))); }
1310 conpat : gcon { $$ = mkident($1); }
1311 | conpat apat { $$ = mkap($1,$2); }
1314 apat : gcon { $$ = mkident($1); }
1315 | qcon OCURLY rpats CCURLY { $$ = mkrecord($1,$3); }
1319 apatc : qvar { $$ = mkident($1); }
1320 | qvar AT apat { $$ = mkas($1,$3); }
1321 | lit_constant { $$ = mklit($1); }
1322 | WILDCARD { $$ = mkwildp(); }
1323 | OPAREN pat CPAREN { $$ = mkpar($2); }
1324 | OPAREN pat COMMA pats CPAREN { $$ = mktuple(mklcons($2,$4)); }
1325 | OBRACK pats CBRACK { $$ = mkllist($2); }
1326 | LAZY apat { $$ = mklazyp($2); }
1330 INTEGER { $$ = mkinteger($1); }
1331 | FLOAT { $$ = mkfloatr($1); }
1332 | CHAR { $$ = mkcharr($1); }
1333 | STRING { $$ = mkstring($1); }
1334 | CHARPRIM { $$ = mkcharprim($1); }
1335 | STRINGPRIM { $$ = mkstringprim($1); }
1336 | INTPRIM { $$ = mkintprim($1); }
1337 | FLOATPRIM { $$ = mkfloatprim($1); }
1338 | DOUBLEPRIM { $$ = mkdoubleprim($1); }
1339 | CLITLIT /* yurble yurble */ { $$ = mkclitlit($1); }
1342 lampats : apat lampats { $$ = mklcons($1,$2); }
1343 | apat { $$ = lsing($1); }
1344 /* right recursion? (WDP) */
1347 pats : pat COMMA pats { $$ = mklcons($1, $3); }
1348 | pat { $$ = lsing($1); }
1349 /* right recursion? (WDP) */
1352 rpats : /* empty */ { $$ = Lnil; }
1356 rpats1 : rpat { $$ = lsing($1); }
1357 | rpats1 COMMA rpat { $$ = lapp($1,$3); }
1360 rpat : qvar { $$ = mkrbind($1,mknothing()); }
1361 | qvar EQUAL pat { $$ = mkrbind($1,mkjust($3)); }
1365 patk : patk qconop bpat { $$ = mkinfixap($2,$1,$3); }
1371 | qconk OCURLY rpats CCURLY { $$ = mkrecord($1,$3); }
1372 | minuskey INTEGER { $$ = mknegate(mklit(mkinteger($2))); }
1373 | minuskey FLOAT { $$ = mknegate(mklit(mkfloatr($2))); }
1376 conpatk : gconk { $$ = mkident($1); }
1377 | conpatk apat { $$ = mkap($1,$2); }
1380 apatck : qvark { $$ = mkident($1); }
1381 | qvark AT apat { $$ = mkas($1,$3); }
1382 | lit_constant { $$ = mklit($1); setstartlineno(); }
1383 | WILDCARD { $$ = mkwildp(); setstartlineno(); }
1384 | oparenkey pat CPAREN { $$ = mkpar($2); }
1385 | oparenkey pat COMMA pats CPAREN { $$ = mktuple(mklcons($2,$4)); }
1386 | obrackkey pats CBRACK { $$ = mkllist($2); }
1387 | lazykey apat { $$ = mklazyp($2); }
1392 | OBRACK CBRACK { $$ = creategid(NILGID); }
1393 | OPAREN CPAREN { $$ = creategid(UNITGID); }
1394 | OPAREN commas CPAREN { $$ = creategid($2); }
1398 | obrackkey CBRACK { $$ = creategid(NILGID); }
1399 | oparenkey CPAREN { $$ = creategid(UNITGID); }
1400 | oparenkey commas CPAREN { $$ = creategid($2); }
1403 /**********************************************************************
1406 * Keywords which record the line start *
1409 **********************************************************************/
1411 importkey: IMPORT { setstartlineno(); $$ = 0; }
1412 | IMPORT SOURCE_UPRAGMA { setstartlineno(); $$ = 1; }
1415 datakey : DATA { setstartlineno();
1418 printf("%u\n",startlineno);
1420 fprintf(stderr,"%u\tdata\n",startlineno);
1425 typekey : TYPE { setstartlineno();
1428 printf("%u\n",startlineno);
1430 fprintf(stderr,"%u\ttype\n",startlineno);
1435 newtypekey : NEWTYPE { setstartlineno();
1438 printf("%u\n",startlineno);
1440 fprintf(stderr,"%u\tnewtype\n",startlineno);
1445 instkey : INSTANCE { setstartlineno();
1448 printf("%u\n",startlineno);
1451 fprintf(stderr,"%u\tinstance\n",startlineno);
1456 defaultkey: DEFAULT { setstartlineno(); }
1459 foreignkey: FOREIGN { setstartlineno(); }
1462 classkey: CLASS { setstartlineno();
1465 printf("%u\n",startlineno);
1467 fprintf(stderr,"%u\tclass\n",startlineno);
1472 modulekey: MODULE { setstartlineno();
1475 printf("%u\n",startlineno);
1477 fprintf(stderr,"%u\tmodule\n",startlineno);
1482 oparenkey: OPAREN { setstartlineno(); }
1485 obrackkey: OBRACK { setstartlineno(); }
1488 lazykey : LAZY { setstartlineno(); }
1491 minuskey: MINUS { setstartlineno(); }
1495 /**********************************************************************
1498 * Basic qualified/unqualified ids/ops *
1501 **********************************************************************/
1504 | OPAREN qvarsym CPAREN { $$ = $2; }
1507 | OPAREN qconsym CPAREN { $$ = $2; }
1510 | BQUOTE qvarid BQUOTE { $$ = $2; }
1513 | BQUOTE qconid BQUOTE { $$ = $2; }
1519 /* Non "-" op, used in right sections */
1524 /* Non "-" varop, used in right sections */
1526 | varsym_nominus { $$ = mknoqual($1); }
1527 | BQUOTE qvarid BQUOTE { $$ = $2; }
1532 | OPAREN varsym CPAREN { $$ = $2; }
1534 con : tycon /* using tycon removes conflicts */
1535 | OPAREN CONSYM CPAREN { $$ = $2; }
1538 | BQUOTE varid BQUOTE { $$ = $2; }
1541 | BQUOTE CONID BQUOTE { $$ = $2; }
1547 qvark : qvarid { setstartlineno(); $$ = $1; }
1548 | oparenkey qvarsym CPAREN { $$ = $2; }
1550 qconk : qconid { setstartlineno(); $$ = $1; }
1551 | oparenkey qconsym CPAREN { $$ = $2; }
1553 vark : varid { setstartlineno(); $$ = $1; }
1554 | oparenkey varsym CPAREN { $$ = $2; }
1558 | varid { $$ = mknoqual($1); }
1561 | varsym { $$ = mknoqual($1); }
1564 | tycon { $$ = mknoqual($1); } /* using tycon removes conflicts */
1567 | CONSYM { $$ = mknoqual($1); }
1570 | tycon { $$ = mknoqual($1); } /* using tycon removes conflicts */
1573 | tycon { $$ = mknoqual($1); } /* using tycon removes conflicts */
1576 varsym : varsym_nominus
1577 | MINUS { $$ = install_literal("-"); }
1580 /* PLUS, BANG are valid varsyms */
1581 varsym_nominus : VARSYM
1582 | PLUS { $$ = install_literal("+"); }
1583 | BANG { $$ = install_literal("!"); }
1586 /* AS HIDING QUALIFIED are valid varids */
1588 | AS { $$ = install_literal("as"); }
1589 | HIDING { $$ = install_literal("hiding"); }
1590 | QUALIFIED { $$ = install_literal("qualified"); }
1598 tyvar : varid { $$ = mknamedtvar(mknoqual($1)); }
1606 tyvar_list: tyvar { $$ = lsing($1); }
1607 | tyvar_list COMMA tyvar { $$ = lapp($1,$3); }
1611 /**********************************************************************
1614 * Stuff to do with layout *
1617 **********************************************************************/
1619 ocurly : layout OCURLY { hsincindent(); }
1621 vocurly : layout { hssetindent(); }
1624 layout : { hsindentoff(); }
1630 FN = NULL; SAMEFN = 0; PREVPATT = NULL;
1635 vccurly : { expect_ccurly = 1; } vccurly1 { expect_ccurly = 0; }
1641 FN = NULL; SAMEFN = 0; PREVPATT = NULL;
1647 FN = NULL; SAMEFN = 0; PREVPATT = NULL;
1654 /**********************************************************************
1656 * Error Processing and Reporting *
1658 * (This stuff is here in case we want to use Yacc macros and such.) *
1660 **********************************************************************/
1667 hsperror("pattern syntax used in expression");
1670 /* The parser calls "hsperror" when it sees a
1671 `report this and die' error. It sets the stage
1672 and calls "yyerror".
1674 There should be no direct calls in the parser to
1675 "yyerror", except for the one from "hsperror". Thus,
1676 the only other calls will be from the error productions
1677 introduced by yacc/bison/whatever.
1679 We need to be able to recognise the from-error-production
1680 case, because we sometimes want to say, "Oh, never mind",
1681 because the layout rule kicks into action and may save
1685 static BOOLEAN error_and_I_mean_it = FALSE;
1691 error_and_I_mean_it = TRUE;
1695 extern char *yytext;
1702 /* We want to be able to distinguish 'error'-raised yyerrors
1703 from yyerrors explicitly coded by the parser hacker.
1705 if ( expect_ccurly && ! error_and_I_mean_it ) {
1709 fprintf(stderr, "%s:%d:%d: %s on input: ",
1710 input_filename, hsplineno, hspcolno + 1, s);
1712 if (yyleng == 1 && *yytext == '\0')
1713 fprintf(stderr, "<EOF>");
1717 format_string(stderr, (unsigned char *) yytext, yyleng);
1720 fputc('\n', stderr);
1722 /* a common problem */
1723 if (strcmp(yytext, "#") == 0)
1724 fprintf(stderr, "\t(Perhaps you forgot a `-cpp' or `-fglasgow-exts' flag?)\n");
1731 format_string(fp, s, len)
1738 case '\0': fputs("\\NUL", fp); break;
1739 case '\007': fputs("\\a", fp); break;
1740 case '\010': fputs("\\b", fp); break;
1741 case '\011': fputs("\\t", fp); break;
1742 case '\012': fputs("\\n", fp); break;
1743 case '\013': fputs("\\v", fp); break;
1744 case '\014': fputs("\\f", fp); break;
1745 case '\015': fputs("\\r", fp); break;
1746 case '\033': fputs("\\ESC", fp); break;
1747 case '\034': fputs("\\FS", fp); break;
1748 case '\035': fputs("\\GS", fp); break;
1749 case '\036': fputs("\\RS", fp); break;
1750 case '\037': fputs("\\US", fp); break;
1751 case '\177': fputs("\\DEL", fp); break;
1756 fprintf(fp, "\\^%c", *s + '@');