2 /* --------------------------------------------------------------------------
3 * Hugs parser (included as part of input.c)
5 * Expect 6 shift/reduce conflicts when passing this grammar through yacc,
6 * but don't worry; they should all be resolved in an appropriate manner.
8 * The Hugs 98 system is Copyright (c) Mark P Jones, Alastair Reid, the
9 * Yale Haskell Group, and the Oregon Graduate Institute of Science and
10 * Technology, 1994-1999, All rights reserved. It is distributed as
11 * free software under the license in the file "License", which is
12 * included in the distribution.
14 * $RCSfile: parser.y,v $
16 * $Date: 2000/02/08 15:32:30 $
17 * ------------------------------------------------------------------------*/
23 #define defTycon(n,l,lhs,rhs,w) tyconDefn(intOf(l),lhs,rhs,w); sp-=n
24 #define sigdecl(l,vs,t) ap(SIGDECL,triple(l,vs,t))
25 #define fixdecl(l,ops,a,p) ap(FIXDECL,\
26 triple(l,ops,mkInt(mkSyntax(a,intOf(p)))))
27 #define grded(gs) ap(GUARDED,gs)
28 #define only(t) ap(ONLY,t)
29 #define letrec(bs,e) (nonNull(bs) ? ap(LETREC,pair(bs,e)) : e)
30 #define qualify(ps,t) (nonNull(ps) ? ap(QUAL,pair(ps,t)) : t)
31 #define exportSelf() singleton(ap(MODULEENT, \
32 mkCon(module(currentModule).text)))
33 #define yyerror(s) /* errors handled elsewhere */
36 static Cell local gcShadow Args((Int,Cell));
37 static Void local syntaxError Args((String));
38 static String local unexpected Args((Void));
39 static Cell local checkPrec Args((Cell));
40 static Void local fixDefn Args((Syntax,Cell,Cell,List));
41 static Cell local buildTuple Args((List));
42 static List local checkCtxt Args((List));
43 static Cell local checkPred Args((Cell));
44 static Pair local checkDo Args((List));
45 static Cell local checkTyLhs Args((Cell));
47 static Void local noTREX Args((String));
50 static Void local noIP Args((String));
53 /* For the purposes of reasonably portable garbage collection, it is
54 * necessary to simulate the YACC stack on the Hugs stack to keep
55 * track of all intermediate constructs. The lexical analyser
56 * pushes a token onto the stack for each token that is found, with
57 * these elements being removed as reduce actions are performed,
58 * taking account of look-ahead tokens as described by gcShadow()
61 * Of the non-terminals used below, only start, topDecl & begin
62 * do not leave any values on the Hugs stack. The same is true for the
63 * terminals EXPR and SCRIPT. At the end of a successful parse, there
64 * should only be one element left on the stack, containing the result
68 #define gc0(e) gcShadow(0,e)
69 #define gc1(e) gcShadow(1,e)
70 #define gc2(e) gcShadow(2,e)
71 #define gc3(e) gcShadow(3,e)
72 #define gc4(e) gcShadow(4,e)
73 #define gc5(e) gcShadow(5,e)
74 #define gc6(e) gcShadow(6,e)
75 #define gc7(e) gcShadow(7,e)
79 %token EXPR CONTEXT SCRIPT
80 %token CASEXP OF DATA TYPE IF
81 %token THEN ELSE WHERE LET IN
82 %token INFIXN INFIXL INFIXR FOREIGN TNEWTYPE
83 %token DEFAULT DERIVING DO TCLASS TINSTANCE
87 %token REPEAT ALL NUMLIT CHARLIT STRINGLIT
88 %token VAROP VARID CONOP CONID
89 %token QVAROP QVARID QCONOP QCONID
91 %token RECSELID IPVARID
93 %token COCO '=' UPTO '@' '\\'
94 %token '|' '-' FROM ARROW '~'
95 %token '!' IMPLIES '(' ',' ')'
96 %token '[' ';' ']' '`' '.'
97 %token TMODULE IMPORT HIDING QUALIFIED ASMOD
98 %token EXPORT UUEXPORT INTERFACE REQUIRES UNSAFE
99 %token INSTIMPORT DYNAMIC CCALL STDKALL
100 %token UTL UTR UUUSAGE
103 /*- Top level script/module structure -------------------------------------*/
105 start : EXPR exp wherePart {inputExpr = letrec($3,$2); sp-=2;}
106 | CONTEXT context {inputContext = $2; sp-=1;}
107 | SCRIPT topModule {valDefns = $2; sp-=1;}
108 | INTERFACE iface {sp-=1;}
109 | error {syntaxError("input");}
113 /*- GHC interface file parsing: -------------------------------------------*/
115 /* Reading in an interface file is surprisingly like reading
116 * a normal Haskell module: we read in a bunch of declarations,
117 * construct symbol table entries, etc. The "only" differences
118 * are that there's no syntactic sugar to deal with and we don't
119 * have to read in expressions.
122 /*- Top-level interface files -----------------------------*/
123 iface : INTERFACE ifCon NUMLIT ifOrphans ifCheckVersion WHERE ifTopDecls
124 {$$ = gc7(ap(I_INTERFACE,
126 | INTERFACE error {syntaxError("interface file");}
129 ifTopDecls: {$$=gc0(NIL);}
130 | ifTopDecl ';' ifTopDecls {$$=gc3(cons($1,$3));}
134 : IMPORT CONID NUMLIT ifOrphans ifOptCOCO ifVersionList
135 {$$=gc6(ap(I_IMPORT,zpair($2,$6))); }
137 | INSTIMPORT CONID {$$=gc2(ap(I_INSTIMPORT,NIL));}
139 | UUEXPORT CONID ifEntities {$$=gc3(ap(I_EXPORT,zpair($2,$3)));}
141 | NUMLIT INFIXL optDigit ifVarCon
142 {$$=gc4(ap(I_FIXDECL,
143 ztriple($3,mkInt(LEFT_ASS),$4)));}
144 | NUMLIT INFIXR optDigit ifVarCon
145 {$$=gc4(ap(I_FIXDECL,
146 ztriple($3,mkInt(RIGHT_ASS),$4)));}
147 | NUMLIT INFIXN optDigit ifVarCon
148 {$$=gc4(ap(I_FIXDECL,
149 ztriple($3,mkInt(NON_ASS),$4)));}
151 | TINSTANCE ifCtxInst ifInstHdL '=' ifVar
152 {$$=gc5(ap(I_INSTANCE,
153 z5ble($1,$2,$3,$5,NIL)));}
155 | NUMLIT TYPE ifCon ifKindedTyvarL '=' ifType
157 z4ble($2,$3,$4,$6)));}
159 | NUMLIT DATA ifCtxDecl ifConData ifKindedTyvarL ifConstrs
161 z5ble($2,$3,$4,$5,$6)));}
163 | NUMLIT TNEWTYPE ifCtxDecl ifConData ifKindedTyvarL ifNewTypeConstr
164 {$$=gc6(ap(I_NEWTYPE,
165 z5ble($2,$3,$4,$5,$6)));}
167 | NUMLIT TCLASS ifCtxDecl ifCon ifKindedTyvar ifCmeths
170 singleton($5),$6)));}
172 | NUMLIT ifVar COCO ifType
174 ztriple($3,$2,$4)));}
176 | error { syntaxError(
177 "interface declaration"); }
181 /*- Top-level misc interface stuff ------------------------*/
182 ifOrphans : '!' {$$=gc1(NIL);}
185 ifOptCOCO : COCO {$$=gc1(NIL);}
189 : NUMLIT {$$ = gc1(NIL); }
194 /*- Interface variable and constructor ids ----------------*/
195 ifTyvar : VARID {$$ = $1;}
197 ifVar : VARID {$$ = gc1($1);}
199 ifCon : CONID {$$ = gc1($1);}
202 ifVarCon : VARID {$$ = gc1($1);}
203 | CONID {$$ = gc1($1);}
206 ifQCon : CONID {$$ = gc1($1);}
207 | QCONID {$$ = gc1($1);}
209 ifConData : ifCon {$$ = gc1($1);}
210 | '(' ')' {$$ = gc2(typeUnit);}
211 | '[' ']' {$$ = gc2(typeList);}
212 | '(' ARROW ')' {$$ = gc3(typeArrow);}
214 ifTCName : CONID { $$ = gc1($1); }
215 | CONOP { $$ = gc1($1); }
216 | '(' ARROW ')' { $$ = gc3(typeArrow); }
217 | '[' ']' { $$ = gc1(typeList); }
219 ifQTCName : ifTCName { $$ = gc1($1); }
220 | QCONID { $$ = gc1($1); }
221 | QCONOP { $$ = gc1($1); }
225 /*- Interface contexts ------------------------------------*/
226 ifCtxInst /* __forall [a b] => :: [((VarId,Kind))] */
227 : ALL ifForall IMPLIES {$$=gc3($2);}
230 ifInstHd /* { Class aType } :: ((ConId, Type)) */
231 : '{' ifQCon ifAType '}' {$$=gc4(ap(DICTAP,
235 ifInstHdL /* { C a1 } -> { C2 a2 } -> ... -> { Cn an } :: Type */
236 : ifInstHd ARROW ifInstHdL {$$=gc3(ap($1,$3));}
237 | ifInstHd {$$=gc1($1);}
240 ifCtxDecl /* {M.C1 a, C2 b} => :: [(QConId, VarId)] */
241 : ifCtxDeclT IMPLIES { $$ = gc2($1); }
244 ifCtxDeclT /* {M.C1 a, C2 b} :: [(QConId, VarId)] */
246 | '{' ifCtxDeclL '}' { $$ = gc3($2); }
249 ifCtxDeclL /* M.C1 a, C2 b :: [(QConId, VarId)] */
250 : ifCtxDeclLE ',' ifCtxDeclL {$$=gc3(cons($1,$3));}
251 | ifCtxDeclLE {$$=gc1(cons($1,NIL));}
254 ifCtxDeclLE /* M.C1 a :: (QConId,VarId) */
255 : ifQCon ifTyvar {$$=gc2(zpair($1,$2));}
259 /*- Interface data declarations - constructor lists -------*/
260 /* The (Type,VarId,Int) are (field type, name (or NIL), strictness).
261 Strictness is a number: mkInt(0) indicates lazy, mkInt(1)
262 indicates a strict field (!type) as in standard H98, and
263 mkInt(2) indicates unpacked -- a GHC extension.
266 ifConstrs /* = Con1 | ... | ConN :: [((ConId,[((Type,VarId,Int))]))] */
268 | '=' ifConstrL {$$ = gc2($2);}
270 ifConstrL /* [((ConId,[((Type,VarId,Int))]))] */
271 : ifConstr {$$ = gc1(singleton($1));}
272 | ifConstr '|' ifConstrL {$$ = gc3(cons($1,$3));}
274 ifConstr /* ((ConId,[((Type,VarId,Int))])) */
275 : ifConData ifDataAnonFieldL {$$ = gc2(zpair($1,$2));}
276 | ifConData '{' ifDataNamedFieldL '}'
277 {$$ = gc4(zpair($1,$3));}
279 ifDataAnonFieldL /* [((Type,VarId,Int))] */
281 | ifDataAnonField ifDataAnonFieldL
282 {$$=gc2(cons($1,$2));}
284 ifDataNamedFieldL /* [((Type,VarId,Int))] */
286 | ifDataNamedField {$$=gc1(cons($1,NIL));}
287 | ifDataNamedField ',' ifDataNamedFieldL
288 {$$=gc3(cons($1,$3));}
290 ifDataAnonField /* ((Type,VarId,Int)) */
291 : ifAType {$$=gc1(ztriple($1,NIL,mkInt(0)));}
292 | '!' ifAType {$$=gc2(ztriple($2,NIL,mkInt(1)));}
293 | '!' '!' ifAType {$$=gc3(ztriple($3,NIL,mkInt(2)));}
295 ifDataNamedField /* ((Type,VarId,Int)) */
296 : ifVar COCO ifAType {$$=gc3(ztriple($3,$1,mkInt(0)));}
297 | ifVar COCO '!' ifAType {$$=gc4(ztriple($4,$1,mkInt(1)));}
298 | ifVar COCO '!' '!' ifAType {$$=gc5(ztriple($5,$1,mkInt(2)));}
302 /*- Interface class declarations - methods ----------------*/
303 ifCmeths /* [((VarId,Type))] */
305 | WHERE '{' ifCmethL '}' { $$ = gc4($3); }
307 ifCmethL /* [((VarId,Type))] */
308 : ifCmeth { $$ = gc1(singleton($1)); }
309 | ifCmeth ';' ifCmethL { $$ = gc3(cons($1,$3)); }
311 ifCmeth /* ((VarId,Type)) */
312 : ifVar COCO ifType { $$ = gc3(zpair($1,$3)); }
313 | ifVar '=' COCO ifType { $$ = gc4(zpair($1,$4)); }
314 /* has default method */
318 /*- Interface newtype declararions ------------------------*/
319 ifNewTypeConstr /* ((ConId,Type)) */
320 : '=' ifCon ifAType { $$ = gc3(zpair($2,$3)); }
324 /*- Interface type expressions ----------------------------*/
325 ifType : ALL ifForall ifCtxDeclT IMPLIES ifType
328 $$=gc5(pair(QUAL,pair($3,$5)));
330 | ifBType ARROW ifType { $$ = gc3(fn($1,$3)); }
331 | ifBType { $$ = gc1($1); }
333 ifForall /* [((VarId,Kind))] */
334 : '[' ifKindedTyvarL ']' { $$ = gc3($2); }
337 ifTypeL2 /* [Type], 2 or more */
338 : ifType ',' ifType { $$ = gc3(doubleton($1,$3)); }
339 | ifType ',' ifTypeL2 { $$ = gc3(cons($1,$3)); }
342 ifTypeL /* [Type], 0 or more */
343 : ifType ',' ifTypeL { $$ = gc3(cons($1,$3)); }
344 | ifType { $$ = gc1(singleton($1)); }
348 ifBType : ifAType { $$ = gc1($1); }
349 | ifBType ifAType { $$ = gc2(ap($1,$2)); }
350 | UUUSAGE ifUsage ifAType { $$ = gc3($3); }
353 ifAType : ifQTCName { $$ = gc1($1); }
354 | ifTyvar { $$ = gc1($1); }
355 | '(' ')' { $$ = gc2(typeUnit); }
356 | '(' ifTypeL2 ')' { $$ = gc3(buildTuple(reverse($2))); }
357 | '[' ifType ']' { $$ = gc3(ap(mkCon(tycon(typeList).text),
359 | '{' ifQTCName ifAType '}' { $$ = gc4(ap(DICTAP,
361 | '(' ifType ')' { $$ = gc3($2); }
362 | UTL ifTypeL UTR { $$ = gc3(ap(UNBOXEDTUP,$2)); }
366 /*- KW's usage stuff --------------------------------------*/
367 ifUsage : '-' { $$ = gc1(NIL); }
368 | '!' { $$ = gc1(NIL); }
369 | ifVar { $$ = gc1(NIL); }
373 /*- Interface kinds ---------------------------------------*/
374 ifKindedTyvarL /* [((VarId,Kind))] */
376 | ifKindedTyvar ifKindedTyvarL { $$ = gc2(cons($1,$2)); }
378 ifKindedTyvar /* ((VarId,Kind)) */
379 : ifTyvar { $$ = gc1(zpair($1,STAR)); }
380 | ifTyvar COCO ifAKind { $$ = gc3(zpair($1,$3)); }
382 ifKind : ifAKind { $$ = gc1($1); }
383 | ifAKind ARROW ifKind { $$ = gc3(ap($1,$3)); }
385 ifAKind : VAROP { $$ = gc1(STAR); }
387 | '(' ifKind ')' { $$ = gc3($2); }
391 /*- Interface version/export/import stuff -----------------*/
394 | ifEntity ifEntities { $$ = gc2(cons($1,$2)); }
397 : ifEntityOcc {$$=gc1($1);}
398 | ifEntityOcc ifStuffInside {$$=gc2(zpair($1,$2));}
401 : ifVar { $$ = gc1($1); }
402 | ifCon { $$ = gc1($1); }
403 | ARROW { $$ = gc1(typeArrow); }
404 | '(' ARROW ')' { $$ = gc3(typeArrow); }
405 /* why allow both? */
408 : '{' ifValOccs '}' { $$ = gc3($2); }
412 | ifVar ifValOccs { $$ = gc2(cons($1,$2)); }
413 | ifCon ifValOccs { $$ = gc2(cons($1,$2)); }
418 | VARID NUMLIT ifVersionList {$$=gc3(cons($1,$3));}
419 | CONID NUMLIT ifVersionList {$$=gc3(cons($1,$3));}
423 /*- Haskell module header/import parsing: -----------------------------------
424 * Syntax for Haskell modules (module headers and imports) is parsed but
425 * most of it is ignored. However, module names in import declarations
426 * are used, of course, if import chasing is turned on.
427 *-------------------------------------------------------------------------*/
429 /* In Haskell 1.2, the default module header was "module Main where"
430 * In 1.3, this changed to "module Main(main) where".
431 * We use the 1.2 header because it breaks much less pre-module code.
433 topModule : startMain begin modBody end {
434 setExportList(singleton(
436 mkCon(module(currentModule).text)
440 | TMODULE modname expspec WHERE '{' modBody end
441 {setExportList($3); $$ = gc7($6);}
442 | TMODULE error {syntaxError("module definition");}
444 /* To implement the Haskell module system, we have to keep track of the
445 * current module. We rely on the use of LALR parsing to ensure that this
446 * side effect happens before any declarations within the module.
448 startMain : /* empty */ {startModule(conMain);
451 modname : CONID {startModule($1); $$ = gc1(NIL);}
453 modid : CONID {$$ = $1;}
454 | STRINGLIT { extern String scriptFile;
456 = findPathname(scriptFile,
457 textToStr(textOf($1)));
459 /* fillin pathname if known */
460 $$ = mkStr(findText(modName));
466 modBody : topDecls {$$ = $1;}
467 | impDecls chase {$$ = gc2(NIL);}
468 | impDecls ';' chase topDecls {$$ = gc4($4);}
471 /*- Exports: --------------------------------------------------------------*/
473 expspec : /* empty */ {$$ = gc0(exportSelf());}
474 | '(' ')' {$$ = gc2(NIL);}
475 | '(' exports ')' {$$ = gc3($2);}
476 | '(' exports ',' ')' {$$ = gc4($2);}
478 exports : exports ',' export {$$ = gc3(cons($3,$1));}
479 | export {$$ = gc1(singleton($1));}
481 /* The qcon should be qconid.
482 * Relaxing the rule lets us explicitly export (:) from the Prelude.
484 export : qvar {$$ = $1;}
486 | qconid '(' UPTO ')' {$$ = gc4(pair($1,DOTDOT));}
487 | qconid '(' qnames ')' {$$ = gc4(pair($1,$3));}
488 | TMODULE modid {$$ = gc2(ap(MODULEENT,$2));}
490 qnames : /* empty */ {$$ = gc0(NIL);}
491 | ',' {$$ = gc1(NIL);}
493 | qnames1 ',' {$$ = gc2($1);}
495 qnames1 : qnames1 ',' qname {$$ = gc3(cons($3,$1));}
496 | qname {$$ = gc1(singleton($1));}
498 qname : qvar {$$ = $1;}
502 /*- Import declarations: --------------------------------------------------*/
504 impDecls : impDecls ';' impDecl {imps = cons($3,imps); $$=gc3(NIL);}
505 | impDecl {imps = singleton($1); $$=gc1(NIL);}
507 chase : /* empty */ {if (chase(imps)) {
517 /* Note that qualified import ignores the import list. */
518 impDecl : IMPORT modid impspec {addQualImport($2,$2);
519 addUnqualImport($2,$3);
521 | IMPORT modid ASMOD modid impspec
522 {addQualImport($2,$4);
523 addUnqualImport($2,$5);
525 | IMPORT QUALIFIED modid ASMOD modid impspec
526 {addQualImport($3,$5);
528 | IMPORT QUALIFIED modid impspec
529 {addQualImport($3,$3);
531 | IMPORT error {syntaxError("import declaration");}
533 impspec : /* empty */ {$$ = gc0(DOTDOT);}
534 | HIDING '(' imports ')' {$$ = gc4(ap(HIDDEN,$3));}
535 | '(' imports ')' {$$ = gc3($2);}
537 imports : /* empty */ {$$ = gc0(NIL);}
538 | ',' {$$ = gc1(NIL);}
539 | imports1 {$$ = $1;}
540 | imports1 ',' {$$ = gc2($1);}
542 imports1 : imports1 ',' import {$$ = gc3(cons($3,$1));}
543 | import {$$ = gc1(singleton($1));}
545 import : var {$$ = $1;}
547 | CONID '(' UPTO ')' {$$ = gc4(pair($1,DOTDOT));}
548 | CONID '(' names ')' {$$ = gc4(pair($1,$3));}
550 names : /* empty */ {$$ = gc0(NIL);}
551 | ',' {$$ = gc1(NIL);}
553 | names1 ',' {$$ = gc2($1);}
555 names1 : names1 ',' name {$$ = gc3(cons($3,$1));}
556 | name {$$ = gc1(singleton($1));}
558 name : var {$$ = $1;}
562 /*- Top-level declarations: -----------------------------------------------*/
564 topDecls : /* empty */ {$$ = gc0(NIL);}
565 | ';' {$$ = gc1(NIL);}
566 | topDecls1 {$$ = $1;}
567 | topDecls1 ';' {$$ = gc2($1);}
569 topDecls1 : topDecls1 ';' topDecl {$$ = gc2($1);}
570 | topDecls1 ';' decl {$$ = gc3(cons($3,$1));}
571 | topDecl {$$ = gc0(NIL);}
572 | decl {$$ = gc1(cons($1,NIL));}
575 /*- Type declarations: ----------------------------------------------------*/
577 topDecl : TYPE tyLhs '=' type {defTycon(4,$3,$2,$4,SYNONYM);}
578 | TYPE tyLhs '=' type IN invars
580 ap($4,$6),RESTRICTSYN);}
581 | TYPE error {syntaxError("type definition");}
582 | DATA btype2 '=' constrs deriving
583 {defTycon(5,$3,checkTyLhs($2),
584 ap(rev($4),$5),DATATYPE);}
585 | DATA context IMPLIES tyLhs '=' constrs deriving
587 ap(qualify($2,rev($6)),
589 | DATA btype2 {defTycon(2,$1,checkTyLhs($2),
590 ap(NIL,NIL),DATATYPE);}
591 | DATA context IMPLIES tyLhs {defTycon(4,$1,$4,
594 | DATA error {syntaxError("data definition");}
595 | TNEWTYPE btype2 '=' nconstr deriving
596 {defTycon(5,$3,checkTyLhs($2),
598 | TNEWTYPE context IMPLIES tyLhs '=' nconstr deriving
602 | TNEWTYPE error {syntaxError("newtype definition");}
604 tyLhs : tyLhs varid {$$ = gc2(ap($1,$2));}
606 | error {syntaxError("type defn lhs");}
608 invars : invars ',' invar {$$ = gc3(cons($3,$1));}
609 | invar {$$ = gc1(cons($1,NIL));}
611 invar : var COCO topType {$$ = gc3(sigdecl($2,singleton($1),
615 constrs : constrs '|' pconstr {$$ = gc3(cons($3,$1));}
616 | pconstr {$$ = gc1(cons($1,NIL));}
618 pconstr : ALL varids '.' qconstr {$$ = gc4(ap(POLYTYPE,
622 qconstr : context IMPLIES constr {$$ = gc3(qualify($1,$3));}
625 constr : '!' btype conop bbtype {$$ = gc4(ap(ap($3,bang($2)),$4));}
626 | btype1 conop bbtype {$$ = gc3(ap(ap($2,$1),$3));}
627 | btype2 conop bbtype {$$ = gc3(ap(ap($2,$1),$3));}
628 | bpolyType conop bbtype {$$ = gc3(ap(ap($2,$1),$3));}
632 | con '{' fieldspecs '}' {$$ = gc4(ap(LABC,pair($1,rev($3))));}
633 | con '{' '}' {$$ = gc3(ap(LABC,pair($1,NIL)));}
634 | error {syntaxError("data type definition");}
636 btype3 : btype2 '!' atype {$$ = gc3(ap($1,bang($3)));}
637 | btype3 '!' atype {$$ = gc3(ap($1,bang($3)));}
638 | btype3 atype {$$ = gc2(ap($1,$2));}
640 btype4 : btype2 bpolyType {$$ = gc2(ap($1,$2));}
641 | btype3 bpolyType {$$ = gc2(ap($1,$2));}
642 | btype4 bpolyType {$$ = gc2(ap($1,$2));}
643 | btype4 atype {$$ = gc2(ap($1,$2));}
644 | btype4 '!' atype {$$ = gc3(ap($1,bang($3)));}
646 bbtype : '!' btype {$$ = gc2(bang($2));}
648 | bpolyType {$$ = $1;}
650 nconstr : pconstr {$$ = gc1(singleton($1));}
652 fieldspecs: fieldspecs ',' fieldspec {$$ = gc3(cons($3,$1));}
653 | fieldspec {$$ = gc1(cons($1,NIL));}
655 fieldspec : vars COCO polyType {$$ = gc3(pair(rev($1),$3));}
656 | vars COCO type {$$ = gc3(pair(rev($1),$3));}
657 | vars COCO '!' type {$$ = gc4(pair(rev($1),bang($4)));}
659 deriving : /* empty */ {$$ = gc0(NIL);}
660 | DERIVING qconid {$$ = gc2(singleton($2));}
661 | DERIVING '(' derivs0 ')' {$$ = gc4($3);}
663 derivs0 : /* empty */ {$$ = gc0(NIL);}
664 | derivs {$$ = gc1(rev($1));}
666 derivs : derivs ',' qconid {$$ = gc3(cons($3,$1));}
667 | qconid {$$ = gc1(singleton($1));}
670 /*- Processing definitions of primitives ----------------------------------*/
672 topDecl : FOREIGN IMPORT callconv DYNAMIC unsafe_flag var COCO type
673 {foreignImport($1,$3,NIL,$6,$8); sp-=8;}
674 | FOREIGN IMPORT callconv ext_loc ext_name unsafe_flag var COCO type
675 {foreignImport($1,$3,pair($4,$5),$7,$9); sp-=9;}
676 | FOREIGN EXPORT callconv DYNAMIC qvarid COCO type
677 {foreignExport($1,$3,$4,$5,$7); sp-=7;}
680 callconv : CCALL {$$ = gc1(textCcall);}
681 | STDKALL {$$ = gc1(textStdcall);}
682 | /* empty */ {$$ = gc0(NIL);}
684 ext_loc : STRINGLIT {$$ = $1;}
686 ext_name : STRINGLIT {$$ = $1;}
688 unsafe_flag: /* empty */ {$$ = gc0(NIL);}
689 | UNSAFE {$$ = gc1(NIL); /* ignored */ }
693 /*- Class declarations: ---------------------------------------------------*/
695 topDecl : TCLASS crule fds wherePart {classDefn(intOf($1),$2,$4,$3); sp-=4;}
696 | TINSTANCE irule wherePart {instDefn(intOf($1),$2,$3); sp-=3;}
697 | DEFAULT '(' dtypes ')' {defaultDefn(intOf($1),$3); sp-=4;}
698 | TCLASS error {syntaxError("class declaration");}
699 | TINSTANCE error {syntaxError("instance declaration");}
700 | DEFAULT error {syntaxError("default declaration");}
702 crule : context IMPLIES btype2 {$$ = gc3(pair($1,checkPred($3)));}
703 | btype2 {$$ = gc1(pair(NIL,checkPred($1)));}
705 irule : context IMPLIES btype2 {$$ = gc3(pair($1,checkPred($3)));}
706 | btype2 {$$ = gc1(pair(NIL,checkPred($1)));}
708 dtypes : /* empty */ {$$ = gc0(NIL);}
709 | dtypes1 {$$ = gc1(rev($1));}
711 dtypes1 : dtypes1 ',' type {$$ = gc3(cons($3,$1));}
712 | type {$$ = gc1(cons($1,NIL));}
715 fds : /* empty */ {$$ = gc0(NIL);}
716 | '|' fds1 {h98DoesntSupport(row,"dependent parameters");
719 fds1 : fds1 ',' fd {$$ = gc3(cons($3,$1));}
720 | fd {$$ = gc1(cons($1,NIL));}
723 fd : varids0 ARROW varids0 {$$ = gc3(pair(rev($1),rev($3)));}
725 varids0 : /* empty */ {$$ = gc0(NIL);}
726 | varids0 varid {$$ = gc2(cons($2,$1));}
729 /*- Type expressions: -----------------------------------------------------*/
731 topType : ALL varids '.' topType0 {$$ = gc4(ap(POLYTYPE,
733 | topType0 {$$ = $1;}
735 topType0 : context IMPLIES topType1 {$$ = gc3(qualify($1,$3));}
736 | topType1 {$$ = $1;}
738 topType1 : bpolyType ARROW topType1 {$$ = gc3(fn($1,$3));}
739 | btype1 ARROW topType1 {$$ = gc3(fn($1,$3));}
740 | btype2 ARROW topType1 {$$ = gc3(fn($1,$3));}
743 polyType : ALL varids '.' sigType {$$ = gc4(ap(POLYTYPE,
745 | context IMPLIES type {$$ = gc3(qualify($1,$3));}
746 | bpolyType {$$ = $1;}
748 bpolyType : '(' polyType ')' {$$ = gc3($2);}
750 varids : varids varid {$$ = gc2(cons($2,$1));}
751 | varid {$$ = gc1(singleton($1));}
753 sigType : context IMPLIES type {$$ = gc3(qualify($1,$3));}
756 context : '(' ')' {$$ = gc2(NIL);}
757 | btype2 {$$ = gc1(singleton(checkPred($1)));}
758 | '(' btype2 ')' {$$ = gc3(singleton(checkPred($2)));}
759 | '(' btypes2 ')' {$$ = gc3(checkCtxt(rev($2)));}
761 | lacks {$$ = gc1(singleton($1));}
762 | '(' lacks1 ')' {$$ = gc3(checkCtxt(rev($2)));}
764 lacks : varid '\\' varid {
766 $$ = gc3(ap(mkExt(textOf($3)),$1));
768 noTREX("a type context");
771 | IPVARID COCO type {
773 $$ = gc3(pair(mkIParam($1),$3));
775 noIP("a type context");
779 lacks1 : btypes2 ',' lacks {$$ = gc3(cons($3,$1));}
780 | lacks1 ',' btype2 {$$ = gc3(cons($3,$1));}
781 | lacks1 ',' lacks {$$ = gc3(cons($3,$1));}
782 | btype2 ',' lacks {$$ = gc3(cons($3,cons($1,NIL)));}
783 | lacks {$$ = gc1(singleton($1));}
787 type : type1 {$$ = $1;}
790 type1 : btype1 {$$ = $1;}
791 | btype1 ARROW type {$$ = gc3(fn($1,$3));}
792 | btype2 ARROW type {$$ = gc3(fn($1,$3));}
793 | error {syntaxError("type expression");}
795 btype : btype1 {$$ = $1;}
798 btype1 : btype1 atype {$$ = gc2(ap($1,$2));}
801 btype2 : btype2 atype {$$ = gc2(ap($1,$2));}
804 atype : atype1 {$$ = $1;}
807 atype1 : varid {$$ = $1;}
808 | '(' ')' {$$ = gc2(typeUnit);}
809 | '(' ARROW ')' {$$ = gc3(typeArrow);}
810 | '(' type1 ')' {$$ = gc3($2);}
811 | '(' btype2 ')' {$$ = gc3($2);}
812 | '(' tupCommas ')' {$$ = gc3($2);}
813 | '(' btypes2 ')' {$$ = gc3(buildTuple($2));}
814 | '(' typeTuple ')' {$$ = gc3(buildTuple($2));}
817 $$ = gc3(revOnto($2,typeNoRow));
822 | '(' tfields '|' type ')' {
824 $$ = gc5(revOnto($2,$4));
829 | '[' type ']' {$$ = gc3(ap(typeList,$2));}
830 | '[' ']' {$$ = gc2(typeList);}
831 | '_' {h98DoesntSupport(row,"anonymous type variables");
832 $$ = gc1(inventVar());}
834 btypes2 : btypes2 ',' btype2 {$$ = gc3(cons($3,$1));}
835 | btype2 ',' btype2 {$$ = gc3(cons($3,cons($1,NIL)));}
837 typeTuple : type1 ',' type {$$ = gc3(cons($3,cons($1,NIL)));}
838 | btype2 ',' type1 {$$ = gc3(cons($3,cons($1,NIL)));}
839 | btypes2 ',' type1 {$$ = gc3(cons($3,$1));}
840 | typeTuple ',' type {$$ = gc3(cons($3,$1));}
843 tfields : tfields ',' tfield {$$ = gc3(cons($3,$1));}
844 | tfield {$$ = gc1(singleton($1));}
846 tfield : varid COCO type {h98DoesntSupport(row,"extensible records");
847 $$ = gc3(ap(mkExt(textOf($1)),$3));}
851 /*- Value declarations: ---------------------------------------------------*/
853 gendecl : INFIXN optDigit ops {$$ = gc3(fixdecl($1,$3,NON_ASS,$2));}
854 | INFIXN error {syntaxError("fixity decl");}
855 | INFIXL optDigit ops {$$ = gc3(fixdecl($1,$3,LEFT_ASS,$2));}
856 | INFIXL error {syntaxError("fixity decl");}
857 | INFIXR optDigit ops {$$ = gc3(fixdecl($1,$3,RIGHT_ASS,$2));}
858 | INFIXR error {syntaxError("fixity decl");}
859 | vars COCO topType {$$ = gc3(sigdecl($2,$1,$3));}
860 | vars COCO error {syntaxError("type signature");}
862 optDigit : NUMLIT {$$ = gc1(checkPrec($1));}
863 | /* empty */ {$$ = gc0(mkInt(DEF_PREC));}
865 ops : ops ',' op {$$ = gc3(cons($3,$1));}
866 | op {$$ = gc1(singleton($1));}
868 vars : vars ',' var {$$ = gc3(cons($3,$1));}
869 | var {$$ = gc1(singleton($1));}
871 decls : '{' decls0 end {$$ = gc3($2);}
872 | '{' decls1 end {$$ = gc3($2);}
874 decls0 : /* empty */ {$$ = gc0(NIL);}
875 | decls0 ';' {$$ = gc2($1);}
876 | decls1 ';' {$$ = gc2($1);}
878 decls1 : decls0 decl {$$ = gc2(cons($2,$1));}
880 decl : gendecl {$$ = $1;}
881 | funlhs rhs {$$ = gc2(ap(FUNBIND,pair($1,$2)));}
882 | funlhs COCO type rhs {$$ = gc4(ap(FUNBIND,
885 | pat0 rhs {$$ = gc2(ap(PATBIND,pair($1,$2)));}
887 funlhs : funlhs0 {$$ = $1;}
891 funlhs0 : pat10_vI varop pat0 {$$ = gc3(ap2($2,$1,$3));}
892 | infixPat varop pat0 {$$ = gc3(ap2($2,$1,$3));}
893 | NUMLIT varop pat0 {$$ = gc3(ap2($2,$1,$3));}
894 | var varop_pl pat0 {$$ = gc3(ap2($2,$1,$3));}
895 | var '+' pat0_INT {$$ = gc3(ap2(varPlus,$1,$3));}
897 funlhs1 : '(' funlhs0 ')' apat {$$ = gc4(ap($2,$4));}
898 | '(' funlhs1 ')' apat {$$ = gc4(ap($2,$4));}
899 | '(' npk ')' apat {$$ = gc4(ap($2,$4));}
900 | var apat {$$ = gc2(ap($1,$2));}
901 | funlhs1 apat {$$ = gc2(ap($1,$2));}
903 rhs : rhs1 wherePart {$$ = gc2(letrec($2,$1));}
904 | error {syntaxError("declaration");}
906 rhs1 : '=' exp {$$ = gc2(pair($1,$2));}
907 | gdrhs {$$ = gc1(grded(rev($1)));}
909 gdrhs : gdrhs gddef {$$ = gc2(cons($2,$1));}
910 | gddef {$$ = gc1(singleton($1));}
912 gddef : '|' exp0 '=' exp {$$ = gc4(pair($3,pair($2,$4)));}
914 wherePart : /* empty */ {$$ = gc0(NIL);}
915 | WHERE decls {$$ = gc2($2);}
918 /*- Patterns: -------------------------------------------------------------*/
923 pat_npk : pat0 COCO type {$$ = gc3(ap(ESIGN,pair($1,$3)));}
926 npk : var '+' NUMLIT {$$ = gc3(ap2(varPlus,$1,$3));}
928 pat0 : var {$$ = $1;}
932 pat0_INT : var {$$ = $1;}
935 pat0_vI : pat10_vI {$$ = $1;}
936 | infixPat {$$ = gc1(ap(INFIX,$1));}
938 infixPat : '-' pat10 {$$ = gc2(ap(NEG,only($2)));}
939 | '-' error {syntaxError("pattern");}
940 | var qconop pat10 {$$ = gc3(ap(ap($2,only($1)),$3));}
941 | var qconop '-' pat10 {$$ = gc4(ap(NEG,ap2($2,only($1),$4)));}
942 | NUMLIT qconop pat10 {$$ = gc3(ap(ap($2,only($1)),$3));}
943 | NUMLIT qconop '-' pat10 {$$ = gc4(ap(NEG,ap2($2,only($1),$4)));}
944 | pat10_vI qconop pat10 {$$ = gc3(ap(ap($2,only($1)),$3));}
945 | pat10_vI qconop '-' pat10 {$$ = gc4(ap(NEG,ap2($2,only($1),$4)));}
946 | infixPat qconop pat10 {$$ = gc3(ap(ap($2,$1),$3));}
947 | infixPat qconop '-' pat10 {$$ = gc4(ap(NEG,ap(ap($2,$1),$4)));}
949 pat10 : fpat {$$ = $1;}
952 pat10_vI : fpat {$$ = $1;}
955 fpat : fpat apat {$$ = gc2(ap($1,$2));}
956 | gcon apat {$$ = gc2(ap($1,$2));}
958 apat : NUMLIT {$$ = $1;}
962 apat_vI : var '@' apat {$$ = gc3(ap(ASPAT,pair($1,$3)));}
964 | qcon '{' patbinds '}' {$$ = gc4(ap(CONFLDS,pair($1,$3)));}
966 | STRINGLIT {$$ = $1;}
967 | '_' {$$ = gc1(WILDCARD);}
968 | '(' pat_npk ')' {$$ = gc3($2);}
969 | '(' npk ')' {$$ = gc3($2);}
970 | '(' pats2 ')' {$$ = gc3(buildTuple($2));}
971 | '[' pats1 ']' {$$ = gc3(ap(FINLIST,rev($2)));}
972 | '~' apat {$$ = gc2(ap(LAZYPAT,$2));}
974 | '(' patfields ')' {
976 $$ = gc3(revOnto($2,nameNoRec));
981 | '(' patfields '|' pat ')' {$$ = gc5(revOnto($2,$4));}
984 pats2 : pats2 ',' pat {$$ = gc3(cons($3,$1));}
985 | pat ',' pat {$$ = gc3(cons($3,singleton($1)));}
987 pats1 : pats1 ',' pat {$$ = gc3(cons($3,$1));}
988 | pat {$$ = gc1(singleton($1));}
990 patbinds : /* empty */ {$$ = gc0(NIL);}
991 | patbinds1 {$$ = gc1(rev($1));}
993 patbinds1 : patbinds1 ',' patbind {$$ = gc3(cons($3,$1));}
994 | patbind {$$ = gc1(singleton($1));}
996 patbind : qvar '=' pat {$$ = gc3(pair($1,$3));}
1000 patfields : patfields ',' patfield {$$ = gc3(cons($3,$1));}
1001 | patfield {$$ = gc1(singleton($1));}
1003 patfield : varid '=' pat {
1005 $$ = gc3(ap(mkExt(textOf($1)),$3));
1007 noTREX("a pattern");
1013 /*- Expressions: ----------------------------------------------------------*/
1015 exp : exp_err {$$ = $1;}
1016 | error {syntaxError("expression");}
1018 exp_err : exp0a COCO sigType {$$ = gc3(ap(ESIGN,pair($1,$3)));}
1019 | exp0a WITH dbinds {
1021 $$ = gc3(ap(WITHEXP,pair($1,$3)));
1023 noIP("an expression");
1028 exp0 : exp0a {$$ = $1;}
1031 exp0a : infixExpa {$$ = gc1(ap(INFIX,$1));}
1034 exp0b : infixExpb {$$ = gc1(ap(INFIX,$1));}
1037 infixExpa : infixExpa qop '-' exp10a {$$ = gc4(ap(NEG,ap(ap($2,$1),$4)));}
1038 | infixExpa qop exp10a {$$ = gc3(ap(ap($2,$1),$3));}
1039 | '-' exp10a {$$ = gc2(ap(NEG,only($2)));}
1040 | exp10a qop '-' exp10a {$$ = gc4(ap(NEG,
1041 ap(ap($2,only($1)),$4)));}
1042 | exp10a qop exp10a {$$ = gc3(ap(ap($2,only($1)),$3));}
1044 infixExpb : infixExpa qop '-' exp10b {$$ = gc4(ap(NEG,ap(ap($2,$1),$4)));}
1045 | infixExpa qop exp10b {$$ = gc3(ap(ap($2,$1),$3));}
1046 | '-' exp10b {$$ = gc2(ap(NEG,only($2)));}
1047 | exp10a qop '-' exp10b {$$ = gc4(ap(NEG,
1048 ap(ap($2,only($1)),$4)));}
1049 | exp10a qop exp10b {$$ = gc3(ap(ap($2,only($1)),$3));}
1051 exp10a : CASEXP exp OF '{' alts end {$$ = gc6(ap(CASE,pair($2,rev($5))));}
1052 | DO '{' stmts end {$$ = gc4(ap(DOCOMP,checkDo($3)));}
1055 exp10b : '\\' pats ARROW exp {$$ = gc4(ap(LAMBDA,
1058 | LET decls IN exp {$$ = gc4(letrec($2,$4));}
1059 | IF exp THEN exp ELSE exp {$$ = gc6(ap(COND,triple($2,$4,$6)));}
1060 | DLET dbinds IN exp {
1062 $$ = gc4(ap(WITHEXP,pair($4,$2)));
1064 noIP("an expression");
1068 pats : pats apat {$$ = gc2(cons($2,$1));}
1069 | apat {$$ = gc1(cons($1,NIL));}
1071 appExp : appExp aexp {$$ = gc2(ap($1,$2));}
1074 aexp : qvar {$$ = $1;}
1075 | qvar '@' aexp {$$ = gc3(ap(ASPAT,pair($1,$3)));}
1076 | '~' aexp {$$ = gc2(ap(LAZYPAT,$2));}
1077 | IPVARID {$$ = $1;}
1078 | '_' {$$ = gc1(WILDCARD);}
1080 | qcon '{' fbinds '}' {$$ = gc4(ap(CONFLDS,pair($1,$3)));}
1081 | aexp '{' fbinds '}' {$$ = gc4(ap(UPDFLDS,
1082 triple($1,NIL,$3)));}
1084 | CHARLIT {$$ = $1;}
1085 | STRINGLIT {$$ = $1;}
1087 | '(' exp ')' {$$ = gc3($2);}
1088 | '(' exps2 ')' {$$ = gc3(buildTuple($2));}
1092 $$ = gc3(revOnto($2,nameNoRec));
1097 | '(' vfields '|' exp ')' {$$ = gc5(revOnto($2,$4));}
1098 | RECSELID {$$ = $1;}
1100 | '[' list ']' {$$ = gc3($2);}
1101 | '(' exp10a qop ')' {$$ = gc4(ap($3,$2));}
1102 | '(' qvarop_mi exp0 ')' {$$ = gc4(ap(ap(nameFlip,$2),$3));}
1103 | '(' qconop exp0 ')' {$$ = gc4(ap(ap(nameFlip,$2),$3));}
1105 exps2 : exps2 ',' exp {$$ = gc3(cons($3,$1));}
1106 | exp ',' exp {$$ = gc3(cons($3,cons($1,NIL)));}
1109 vfields : vfields ',' vfield {$$ = gc3(cons($3,$1));}
1110 | vfield {$$ = gc1(singleton($1));}
1112 vfield : varid '=' exp {
1114 $$ = gc3(ap(mkExt(textOf($1)),$3));
1116 noTREX("an expression");
1121 alts : alts1 {$$ = $1;}
1122 | alts1 ';' {$$ = gc2($1);}
1124 alts1 : alts1 ';' alt {$$ = gc3(cons($3,$1));}
1125 | alt {$$ = gc1(cons($1,NIL));}
1127 alt : pat altRhs wherePart {$$ = gc3(pair($1,letrec($3,$2)));}
1129 altRhs : guardAlts {$$ = gc1(grded(rev($1)));}
1130 | ARROW exp {$$ = gc2(pair($1,$2));}
1131 | error {syntaxError("case expression");}
1133 guardAlts : guardAlts guardAlt {$$ = gc2(cons($2,$1));}
1134 | guardAlt {$$ = gc1(cons($1,NIL));}
1136 guardAlt : '|' exp0 ARROW exp {$$ = gc4(pair($3,pair($2,$4)));}
1138 stmts : stmts1 ';' {$$ = gc2($1);}
1141 stmts1 : stmts1 ';' stmt {$$ = gc3(cons($3,$1));}
1142 | stmt {$$ = gc1(cons($1,NIL));}
1144 stmt : exp_err FROM exp {$$ = gc3(ap(FROMQUAL,pair($1,$3)));}
1145 | LET decls {$$ = gc2(ap(QWHERE,$2));}
1146 /* | IF exp {$$ = gc2(ap(BOOLQUAL,$2));}*/
1147 | exp_err {$$ = gc1(ap(DOQUAL,$1));}
1149 fbinds : /* empty */ {$$ = gc0(NIL);}
1150 | fbinds1 {$$ = gc1(rev($1));}
1152 fbinds1 : fbinds1 ',' fbind {$$ = gc3(cons($3,$1));}
1153 | fbind {$$ = gc1(singleton($1));}
1155 fbind : var {$$ = $1;}
1156 | qvar '=' exp {$$ = gc3(pair($1,$3));}
1159 dbinds : '{' dbs0 end {$$ = gc3($2);}
1160 | '{' dbs1 end {$$ = gc3($2);}
1162 dbs0 : /* empty */ {$$ = gc0(NIL);}
1163 | dbs0 ';' {$$ = gc2($1);}
1164 | dbs1 ';' {$$ = gc2($1);}
1166 dbs1 : dbs0 dbind {$$ = gc2(cons($2,$1));}
1168 dbind : IPVARID '=' exp {$$ = gc3(pair($1,$3));}
1171 /*- List Expressions: -------------------------------------------------------*/
1173 list : exp {$$ = gc1(ap(FINLIST,cons($1,NIL)));}
1174 | exps2 {$$ = gc1(ap(FINLIST,rev($1)));}
1175 | exp '|' quals {$$ = gc3(ap(COMP,pair($1,rev($3))));}
1176 | exp UPTO exp {$$ = gc3(ap(ap(nameFromTo,$1),$3));}
1177 | exp ',' exp UPTO {$$ = gc4(ap(ap(nameFromThen,$1),$3));}
1178 | exp UPTO {$$ = gc2(ap(nameFrom,$1));}
1179 | exp ',' exp UPTO exp {$$ = gc5(ap(ap(ap(nameFromThenTo,
1182 quals : quals ',' qual {$$ = gc3(cons($3,$1));}
1183 | qual {$$ = gc1(cons($1,NIL));}
1185 qual : exp FROM exp {$$ = gc3(ap(FROMQUAL,pair($1,$3)));}
1186 | exp {$$ = gc1(ap(BOOLQUAL,$1));}
1187 | LET decls {$$ = gc2(ap(QWHERE,$2));}
1190 /*- Identifiers and symbols: ----------------------------------------------*/
1192 gcon : qcon {$$ = $1;}
1193 | '(' ')' {$$ = gc2(nameUnit);}
1194 | '[' ']' {$$ = gc2(nameNil);}
1195 | '(' tupCommas ')' {$$ = gc3($2);}
1197 tupCommas : tupCommas ',' {$$ = gc2(mkTuple(tupleOf($1)+1));}
1198 | ',' {$$ = gc1(mkTuple(2));}
1200 varid : VARID {$$ = $1;}
1201 | HIDING {$$ = gc1(varHiding);}
1202 | QUALIFIED {$$ = gc1(varQualified);}
1203 | ASMOD {$$ = gc1(varAsMod);}
1205 qconid : QCONID {$$ = $1;}
1208 var : varid {$$ = $1;}
1209 | '(' VAROP ')' {$$ = gc3($2);}
1210 | '(' '+' ')' {$$ = gc3(varPlus);}
1211 | '(' '-' ')' {$$ = gc3(varMinus);}
1212 | '(' '!' ')' {$$ = gc3(varBang);}
1213 | '(' '.' ')' {$$ = gc3(varDot);}
1215 qvar : QVARID {$$ = $1;}
1216 | '(' QVAROP ')' {$$ = gc3($2);}
1219 con : CONID {$$ = $1;}
1220 | '(' CONOP ')' {$$ = gc3($2);}
1222 qcon : QCONID {$$ = $1;}
1223 | '(' QCONOP ')' {$$ = gc3($2);}
1226 varop : '+' {$$ = gc1(varPlus);}
1227 | '-' {$$ = gc1(varMinus);}
1228 | varop_mipl {$$ = $1;}
1230 varop_mi : '+' {$$ = gc1(varPlus);}
1231 | varop_mipl {$$ = $1;}
1233 varop_pl : '-' {$$ = gc1(varMinus);}
1234 | varop_mipl {$$ = $1;}
1236 varop_mipl: VAROP {$$ = $1;}
1237 | '`' varid '`' {$$ = gc3($2);}
1238 | '!' {$$ = gc1(varBang);}
1239 | '.' {$$ = gc1(varDot);}
1241 qvarop : '-' {$$ = gc1(varMinus);}
1242 | qvarop_mi {$$ = $1;}
1244 qvarop_mi : QVAROP {$$ = $1;}
1245 | '`' QVARID '`' {$$ = gc3($2);}
1246 | varop_mi {$$ = $1;}
1249 conop : CONOP {$$ = $1;}
1250 | '`' CONID '`' {$$ = gc3($2);}
1252 qconop : QCONOP {$$ = $1;}
1253 | '`' QCONID '`' {$$ = gc3($2);}
1256 op : varop {$$ = $1;}
1259 qop : qvarop {$$ = $1;}
1263 /*- Stuff from STG hugs ---------------------------------------------------*/
1265 qvarid : varid1 {$$ = gc1($1);}
1266 | QVARID {$$ = gc1($1);}
1268 varid1 : VARID {$$ = gc1($1);}
1269 | HIDING {$$ = gc1(varHiding);}
1270 | QUALIFIED {$$ = gc1(varQualified);}
1271 | ASMOD {$$ = gc1(varAsMod);}
1274 /*- Tricks to force insertion of leading and closing braces ---------------*/
1276 begin : error {yyerrok;
1277 if (offsideON) goOffside(startColumn);}
1279 /* deal with trailing semicolon */
1280 end : '}' {$$ = $1;}
1282 if (offsideON && canUnOffside()) {
1284 /* insert extra token on stack*/
1286 pushed(0) = pushed(1);
1287 pushed(1) = mkInt(column);
1290 syntaxError("definition");
1294 /*-------------------------------------------------------------------------*/
1298 static Cell local gcShadow(n,e) /* keep parsed fragments on stack */
1301 /* If a look ahead token is held then the required stack transformation
1304 * x1 | ... | xn | la ===> e | la
1307 * Otherwise, the transformation is:
1309 * x1 | ... | xn ===> e
1313 pushed(n-1) = top();
1322 static Void local syntaxError(s) /* report on syntax error */
1324 ERRMSG(row) "Syntax error in %s (unexpected %s)", s, unexpected()
1328 static String local unexpected() { /* find name for unexpected token */
1329 static char buffer[100];
1330 static char *fmt = "%s \"%s\"";
1331 static char *kwd = "keyword";
1334 case 0 : return "end of input";
1336 #define keyword(kw) sprintf(buffer,fmt,kwd,kw); return buffer;
1337 case INFIXL : keyword("infixl");
1338 case INFIXR : keyword("infixr");
1339 case INFIXN : keyword("infix");
1340 case FOREIGN : keyword("foreign");
1341 case UNSAFE : keyword("unsafe");
1342 case TINSTANCE : keyword("instance");
1343 case TCLASS : keyword("class");
1344 case CASEXP : keyword("case");
1345 case OF : keyword("of");
1346 case IF : keyword("if");
1347 case THEN : keyword("then");
1348 case ELSE : keyword("else");
1349 case WHERE : keyword("where");
1350 case TYPE : keyword("type");
1351 case DATA : keyword("data");
1352 case TNEWTYPE : keyword("newtype");
1353 case LET : keyword("let");
1354 case IN : keyword("in");
1355 case DERIVING : keyword("deriving");
1356 case DEFAULT : keyword("default");
1357 case IMPORT : keyword("import");
1358 case TMODULE : keyword("module");
1359 /* AJG: Hugs98/Classic use the keyword forall
1360 rather than __forall.
1361 Agree on one or the other
1363 case ALL : keyword("__forall");
1365 case DLET : keyword("dlet");
1366 case WITH : keyword("with");
1370 case ARROW : return "`->'";
1371 case '=' : return "`='";
1372 case COCO : return "`::'";
1373 case '-' : return "`-'";
1374 case '!' : return "`!'";
1375 case ',' : return "comma";
1376 case '@' : return "`@'";
1377 case '(' : return "`('";
1378 case ')' : return "`)'";
1379 case '{' : return "`{', possibly due to bad layout";
1380 case '}' : return "`}', possibly due to bad layout";
1381 case '_' : return "`_'";
1382 case '|' : return "`|'";
1383 case '.' : return "`.'";
1384 case ';' : return "`;', possibly due to bad layout";
1385 case UPTO : return "`..'";
1386 case '[' : return "`['";
1387 case ']' : return "`]'";
1388 case FROM : return "`<-'";
1389 case '\\' : return "backslash (lambda)";
1390 case '~' : return "tilde";
1391 case '`' : return "backquote";
1393 case RECSELID : sprintf(buffer,"selector \"#%s\"",
1394 textToStr(extText(snd(yylval))));
1398 case IPVARID : sprintf(buffer,"implicit parameter \"?%s\"",
1399 textToStr(textOf(yylval)));
1405 case CONID : sprintf(buffer,"symbol \"%s\"",
1406 textToStr(textOf(yylval)));
1411 case QCONID : sprintf(buffer,"symbol \"%s\"",
1412 identToStr(yylval));
1414 case HIDING : return "symbol \"hiding\"";
1415 case QUALIFIED : return "symbol \"qualified\"";
1416 case ASMOD : return "symbol \"as\"";
1417 case NUMLIT : return "numeric literal";
1418 case CHARLIT : return "character literal";
1419 case STRINGLIT : return "string literal";
1420 case IMPLIES : return "`=>'";
1421 default : return "token";
1425 static Cell local checkPrec(p) /* Check for valid precedence value*/
1427 if (!isInt(p) || intOf(p)<MIN_PREC || intOf(p)>MAX_PREC) {
1428 ERRMSG(row) "Precedence value must be an integer in the range [%d..%d]",
1435 static Cell local buildTuple(tup) /* build tuple (x1,...,xn) from */
1436 List tup; { /* list [xn,...,x1] */
1442 x = fst(t); /* / \ / \ */
1443 fst(t) = snd(t); /* xn . . xn */
1444 snd(t) = x; /* . ===> . */
1446 t = fun(x); /* . . */
1448 } while (nonNull(t)); /* x1 NIL (n) x1 */
1449 fst(x) = mkTuple(n);
1453 static List local checkCtxt(con) /* validate context */
1455 mapOver(checkPred, con);
1459 static Cell local checkPred(c) /* check that type expr is a valid */
1460 Cell c; { /* constraint */
1461 Cell cn = getHead(c);
1463 if (isExt(cn) && argCount==1)
1470 if (!isQCon(cn) /*|| argCount==0*/)
1471 syntaxError("class expression");
1475 static Pair local checkDo(dqs) /* convert reversed list of dquals */
1476 List dqs; { /* to an (expr,quals) pair */
1477 if (isNull(dqs) || whatIs(hd(dqs))!=DOQUAL) {
1478 ERRMSG(row) "Last generator in do {...} must be an expression"
1481 fst(dqs) = snd(fst(dqs)); /* put expression in fst of pair */
1482 snd(dqs) = rev(snd(dqs)); /* & reversed list of quals in snd */
1486 static Cell local checkTyLhs(c) /* check that lhs is of the form */
1487 Cell c; { /* T a1 ... a */
1489 while (isAp(tlhs) && whatIs(arg(tlhs))==VARIDCELL) {
1492 if (whatIs(tlhs)!=CONIDCELL) {
1493 ERRMSG(row) "Illegal left hand side in datatype definition"
1501 static Void local noTREX(where)
1503 ERRMSG(row) "Attempt to use TREX records while parsing %s.\n", where ETHEN
1504 ERRTEXT "(TREX is disabled in this build of Hugs)"
1509 static Void local noIP(where)
1511 ERRMSG(row) "Attempt to use Implicit Parameters while parsing %s.\n", where ETHEN
1512 ERRTEXT "(Implicit Parameters are disabled in this build of Hugs)"
1517 /*-------------------------------------------------------------------------*/