1Parsetree(3)                     OCaml library                    Parsetree(3)
2
3
4

NAME

6       Parsetree - Abstract syntax tree produced by parsing
7

Module

9       Module   Parsetree
10

Documentation

12       Module Parsetree
13        : sig end
14
15
16       Abstract syntax tree produced by parsing
17
18       Warning: this module is unstable and part of Compiler_libs .
19
20
21
22
23
24       type constant =
25        | Pconst_integer of string * char option
26         (* Integer constants such as 3 3l 3L 3n .
27
28       Suffixes  [g-z][G-Z] are accepted by the parser.  Suffixes except 'l' ,
29       'L' and 'n' are rejected by the typechecker
30        *)
31        | Pconst_char of char
32         (* Character such as 'c' .
33        *)
34        | Pconst_string of string * Location.t * string option
35         (* Constant string such as "constant" or {delim|other constant|delim}
36       .
37
38       The location span the content of the string, without the delimiters.
39        *)
40        | Pconst_float of string * char option
41         (* Float constant such as 3.4 , 2e5 or 1.4e-4 .
42
43       Suffixes  g-z G-Z are accepted by the parser.  Suffixes are rejected by
44       the typechecker.
45        *)
46
47
48
49
50       type location_stack = Location.t list
51
52
53
54
55
56
57   Extension points
58       type attribute = {
59        attr_name : string Asttypes.loc ;
60        attr_payload : payload ;
61        attr_loc : Location.t ;
62        }
63
64
65       Attributes such as [@id ARG] and [@@id ARG] .
66
67       Metadata containers passed around within the AST.  The compiler ignores
68       unknown attributes.
69
70
71       type extension = string Asttypes.loc * payload
72
73
74       Extension points such as [%id ARG] and [%%id ARG] .
75
76       Sub-language placeholder -- rejected by the typechecker.
77
78
79       type attributes = attribute list
80
81
82
83
84       type payload =
85        | PStr of structure
86        | PSig of signature
87         (* : SIG in an attribute or an extension point
88        *)
89        | PTyp of core_type
90         (* : T in an attribute or an extension point
91        *)
92        | PPat of pattern * expression option
93         (* ? P or ? P when E , in an attribute or an extension point
94        *)
95
96
97
98
99
100
101   Core language
102   Type expressions
103       type core_type = {
104        ptyp_desc : core_type_desc ;
105        ptyp_loc : Location.t ;
106        ptyp_loc_stack : location_stack ;
107        ptyp_attributes : attributes ;  (* ... [@id1] [@id2]
108
109        *)
110        }
111
112
113
114
115       type core_type_desc =
116        | Ptyp_any  (* _
117
118        *)
119        | Ptyp_var of string
120         (* A type variable such as 'a
121
122        *)
123        | Ptyp_arrow of Asttypes.arg_label * core_type * core_type
124         (* Ptyp_arrow(lbl, T1, T2) represents:
125
126       - T1 -> T2 when lbl is Asttypes.arg_label.Nolabel ,
127
128       - ~l:T1 -> T2 when lbl is Asttypes.arg_label.Labelled ,
129
130       - ?l:T1 -> T2 when lbl is Asttypes.arg_label.Optional .
131
132        *)
133        | Ptyp_tuple of core_type list
134         (*  Ptyp_tuple([T1  ; ... ; Tn]) represents a product type T1 * ... *
135       Tn .
136
137       Invariant: n >= 2 .
138        *)
139        | Ptyp_constr of Longident.t Asttypes.loc * core_type list
140         (* Ptyp_constr(lident, l) represents:
141
142       - tconstr when l=[] ,
143
144       - T tconstr when l=[T] ,
145
146       - (T1, ..., Tn) tconstr when l=[T1 ; ... ; Tn] .
147
148        *)
149        | Ptyp_object of object_field list * Asttypes.closed_flag
150         (* Ptyp_object([ l1:T1; ...; ln:Tn ], flag) represents:
151
152       - < l1:T1; ...; ln:Tn > when flag is Asttypes.closed_flag.Closed ,
153
154       - < l1:T1; ...; ln:Tn; .. > when flag is Asttypes.closed_flag.Open .
155
156        *)
157        | Ptyp_class of Longident.t Asttypes.loc * core_type list
158         (* Ptyp_class(tconstr, l) represents:
159
160       - #tconstr when l=[] ,
161
162       - T #tconstr when l=[T] ,
163
164       - (T1, ..., Tn) #tconstr when l=[T1 ; ... ; Tn] .
165
166        *)
167        | Ptyp_alias of core_type * string
168         (* T as 'a .
169        *)
170        | Ptyp_variant of row_field list * Asttypes.closed_flag * Asttypes.la‐
171       bel list option
172         (* Ptyp_variant([`A;`B], flag, labels) represents:
173
174       -  [  `A|`B  ] when flag is Asttypes.closed_flag.Closed , and labels is
175       None ,
176
177       - [> `A|`B ] when flag is Asttypes.closed_flag.Open  ,  and  labels  is
178       None ,
179
180       -  [<  `A|`B ] when flag is Asttypes.closed_flag.Closed , and labels is
181       Some [] ,
182
183       - [< `A|`B > `X `Y ] when flag is Asttypes.closed_flag.Closed , and la‐
184       bels is Some ["X";"Y"] .
185
186        *)
187        | Ptyp_poly of string Asttypes.loc list * core_type
188         (* 'a1 ... 'an. T
189
190       Can only appear in the following context:
191
192
193       -As the Parsetree.core_type of a Parsetree.pattern_desc.Ppat_constraint
194       node corresponding to a constraint on a let-binding:
195       let x : 'a1 ... 'an. T = e ...
196
197
198       -Under Parsetree.class_field_kind.Cfk_virtual for methods (not values).
199
200
201       -As       the       Parsetree.core_type       of        a        Parse‐
202       tree.class_type_field_desc.Pctf_method node.
203
204
205       -As  the  Parsetree.core_type  of a Parsetree.expression_desc.Pexp_poly
206       node.
207
208
209       -As the Parsetree.label_declaration.pld_type field of  a  Parsetree.la‐
210       bel_declaration .
211
212
213       -As  a  Parsetree.core_type  of  a Parsetree.core_type_desc.Ptyp_object
214       node.
215
216
217       -As  the  Parsetree.value_description.pval_type  field  of   a   Parse‐
218       tree.value_description .
219
220        *)
221        | Ptyp_package of package_type
222         (* (module S) .
223        *)
224        | Ptyp_extension of extension
225         (* [%id] .
226        *)
227
228
229
230
231       type  package_type  =  Longident.t  Asttypes.loc  *  (Longident.t  Ast‐
232       types.loc * core_type) list
233
234
235       As Parsetree.package_type typed values:
236
237       - (S, []) represents (module S) ,
238
239       - (S, [(t1, T1) ; ... ; (tn, Tn)]) represents (module S with type t1  =
240       T1 and ... and tn = Tn) .
241
242
243
244       type row_field = {
245        prf_desc : row_field_desc ;
246        prf_loc : Location.t ;
247        prf_attributes : attributes ;
248        }
249
250
251
252
253       type row_field_desc =
254        | Rtag of Asttypes.label Asttypes.loc * bool * core_type list
255         (* Rtag(`A, b, l) represents:
256
257       - `A when b is true and l is [] ,
258
259       - `A of T when b is false and l is [T] ,
260
261       - `A of T1 & .. & Tn when b is false and l is [T1;...Tn] ,
262
263       - `A of & T1 & .. & Tn when b is true and l is [T1;...Tn] .
264
265
266       -The  bool  field  is  true if the tag contains a constant (empty) con‐
267       structor.
268
269       - & occurs when several types are used for the  same  constructor  (see
270       4.2 in the manual)
271
272        *)
273        | Rinherit of core_type
274         (* [ | t ]
275
276        *)
277
278
279
280
281       type object_field = {
282        pof_desc : object_field_desc ;
283        pof_loc : Location.t ;
284        pof_attributes : attributes ;
285        }
286
287
288
289
290       type object_field_desc =
291        | Otag of Asttypes.label Asttypes.loc * core_type
292        | Oinherit of core_type
293
294
295
296
297
298
299   Patterns
300       type pattern = {
301        ppat_desc : pattern_desc ;
302        ppat_loc : Location.t ;
303        ppat_loc_stack : location_stack ;
304        ppat_attributes : attributes ;  (* ... [@id1] [@id2]
305
306        *)
307        }
308
309
310
311
312       type pattern_desc =
313        | Ppat_any  (* The pattern _ .
314        *)
315        | Ppat_var of string Asttypes.loc
316         (* A variable pattern such as x
317
318        *)
319        | Ppat_alias of pattern * string Asttypes.loc
320         (* An alias pattern such as P as 'a
321
322        *)
323        | Ppat_constant of constant
324         (* Patterns such as 1 , 'a' , "true" , 1.0 , 1l , 1L , 1n
325
326        *)
327        | Ppat_interval of constant * constant
328         (* Patterns such as 'a'..'z' .
329
330       Other  forms  of  interval are recognized by the parser but rejected by
331       the type-checker.
332        *)
333        | Ppat_tuple of pattern list
334         (* Patterns (P1, ..., Pn) .
335
336       Invariant: n >= 2
337
338        *)
339        | Ppat_construct of Longident.t Asttypes.loc  *  (string  Asttypes.loc
340       list * pattern) option
341         (* Ppat_construct(C, args) represents:
342
343       - C when args is None ,
344
345       - C P when args is Some ([], P)
346
347
348       - C (P1, ..., Pn) when args is Some ([], Ppat_tuple [P1; ...; Pn])
349
350
351       - C (type a b) P when args is Some ([a; b], P)
352
353
354        *)
355        | Ppat_variant of Asttypes.label * pattern option
356         (* Ppat_variant(`A, pat) represents:
357
358       - `A when pat is None ,
359
360       - `A P when pat is Some P
361
362
363        *)
364        |  Ppat_record  of  (Longident.t  Asttypes.loc  * pattern) list * Ast‐
365       types.closed_flag
366         (* Ppat_record([(l1, P1) ; ... ; (ln, Pn)], flag) represents:
367
368       - { l1=P1; ...; ln=Pn } when flag is Asttypes.closed_flag.Closed
369
370
371       - { l1=P1; ...; ln=Pn; _} when flag is Asttypes.closed_flag.Open
372
373       Invariant: n > 0
374
375        *)
376        | Ppat_array of pattern list
377         (* Pattern [| P1; ...; Pn |]
378
379        *)
380        | Ppat_or of pattern * pattern
381         (* Pattern P1 | P2
382
383        *)
384        | Ppat_constraint of pattern * core_type
385         (* Pattern (P : T)
386
387        *)
388        | Ppat_type of Longident.t Asttypes.loc
389         (* Pattern #tconst
390
391        *)
392        | Ppat_lazy of pattern
393         (* Pattern lazy P
394
395        *)
396        | Ppat_unpack of string option Asttypes.loc
397         (* Ppat_unpack(s) represents:
398
399       - (module P) when s is Some "P"
400
401
402       - (module _) when s is None
403
404       Note: (module P : S) is represented as Ppat_constraint(Ppat_unpack(Some
405       "P"), Ptyp_package S)
406
407        *)
408        | Ppat_exception of pattern
409         (* Pattern exception P
410
411        *)
412        | Ppat_extension of extension
413         (* Pattern [%id]
414
415        *)
416        | Ppat_open of Longident.t Asttypes.loc * pattern
417         (* Pattern M.(P)
418
419        *)
420
421
422
423
424
425
426   Value expressions
427       type expression = {
428        pexp_desc : expression_desc ;
429        pexp_loc : Location.t ;
430        pexp_loc_stack : location_stack ;
431        pexp_attributes : attributes ;  (* ... [@id1] [@id2]
432
433        *)
434        }
435
436
437
438
439       type expression_desc =
440        | Pexp_ident of Longident.t Asttypes.loc
441         (* Identifiers such as x and M.x
442
443        *)
444        | Pexp_constant of constant
445         (* Expressions constant such as 1 , 'a' , "true" , 1.0 , 1l , 1L , 1n
446
447        *)
448        | Pexp_let of Asttypes.rec_flag * value_binding list * expression
449         (* Pexp_let(flag, [(P1,E1) ; ... ; (Pn,En)], E) represents:
450
451       -  let  P1  =  E1  and  ...  and  Pn  =  EN  in  E  when  flag  is Ast‐
452       types.rec_flag.Nonrecursive ,
453
454       - let rec P1 = E1 and  ...  and  Pn  =  EN  in  E  when  flag  is  Ast‐
455       types.rec_flag.Recursive .
456
457        *)
458        | Pexp_function of case list
459         (* function P1 -> E1 | ... | Pn -> En
460
461        *)
462        |  Pexp_fun  of Asttypes.arg_label * expression option * pattern * ex‐
463       pression
464         (* Pexp_fun(lbl, exp0, P, E1) represents:
465
466       - fun P -> E1 when lbl is Asttypes.arg_label.Nolabel and exp0 is None
467
468
469       - fun ~l:P -> E1 when lbl is Asttypes.arg_label.Labelled  and  exp0  is
470       None
471
472
473       -  fun  ?l:P  -> E1 when lbl is Asttypes.arg_label.Optional and exp0 is
474       None
475
476
477       - fun ?l:(P = E0) -> E1 when  lbl  is  Asttypes.arg_label.Optional  and
478       exp0 is Some E0
479
480       Notes:
481
482       -If E0 is provided, only Asttypes.arg_label.Optional is allowed.
483
484       -  fun  P1  P2  ..  Pn -> E1 is represented as nested Parsetree.expres‐
485       sion_desc.Pexp_fun .
486
487       - let f P = E is represented using Parsetree.expression_desc.Pexp_fun .
488
489        *)
490        | Pexp_apply of expression * (Asttypes.arg_label * expression) list
491         (* Pexp_apply(E0, [(l1, E1) ; ... ; (ln, En)]) represents  E0  ~l1:E1
492       ... ~ln:En
493
494
495       li  can  be  Asttypes.arg_label.Nolabel  (non  labeled  argument), Ast‐
496       types.arg_label.Labelled (labelled arguments) or Asttypes.arg_label.Op‐
497       tional (optional argument).
498
499       Invariant: n > 0
500
501        *)
502        | Pexp_match of expression * case list
503         (* match E0 with P1 -> E1 | ... | Pn -> En
504
505        *)
506        | Pexp_try of expression * case list
507         (* try E0 with P1 -> E1 | ... | Pn -> En
508
509        *)
510        | Pexp_tuple of expression list
511         (* Expressions (E1, ..., En)
512
513       Invariant: n >= 2
514
515        *)
516        | Pexp_construct of Longident.t Asttypes.loc * expression option
517         (* Pexp_construct(C, exp) represents:
518
519       - C when exp is None ,
520
521       - C E when exp is Some E ,
522
523       - C (E1, ..., En) when exp is Some (Pexp_tuple[E1;...;En])
524
525
526        *)
527        | Pexp_variant of Asttypes.label * expression option
528         (* Pexp_variant(`A, exp) represents
529
530       - `A when exp is None
531
532
533       - `A E when exp is Some E
534
535
536        *)
537        |  Pexp_record  of  (Longident.t Asttypes.loc * expression) list * ex‐
538       pression option
539         (* Pexp_record([(l1,P1) ; ... ; (ln,Pn)], exp0) represents
540
541       - { l1=P1; ...; ln=Pn } when exp0 is None
542
543
544       - { E0 with l1=P1; ...; ln=Pn } when exp0 is Some E0
545
546       Invariant: n > 0
547
548        *)
549        | Pexp_field of expression * Longident.t Asttypes.loc
550         (* E.l
551
552        *)
553        | Pexp_setfield of expression * Longident.t Asttypes.loc * expression
554         (* E1.l <- E2
555
556        *)
557        | Pexp_array of expression list
558         (* [| E1; ...; En |]
559
560        *)
561        | Pexp_ifthenelse of expression * expression * expression option
562         (* if E1 then E2 else E3
563
564        *)
565        | Pexp_sequence of expression * expression
566         (* E1; E2
567
568        *)
569        | Pexp_while of expression * expression
570         (* while E1 do E2 done
571
572        *)
573        | Pexp_for of pattern *  expression  *  expression  *  Asttypes.direc‐
574       tion_flag * expression
575         (* Pexp_for(i, E1, E2, direction, E3) represents:
576
577       -  for  i  =  E1  to  E2  do  E3 done when direction is Asttypes.direc‐
578       tion_flag.Upto
579
580
581       - for i = E1 downto E2 do E3 done  when  direction  is  Asttypes.direc‐
582       tion_flag.Downto
583
584
585        *)
586        | Pexp_constraint of expression * core_type
587         (* (E : T)
588
589        *)
590        | Pexp_coerce of expression * core_type option * core_type
591         (* Pexp_coerce(E, from, T) represents
592
593       - (E :> T) when from is None ,
594
595       - (E : T0 :> T) when from is Some T0 .
596
597        *)
598        | Pexp_send of expression * Asttypes.label Asttypes.loc
599         (* E # m
600
601        *)
602        | Pexp_new of Longident.t Asttypes.loc
603         (* new M.c
604
605        *)
606        | Pexp_setinstvar of Asttypes.label Asttypes.loc * expression
607         (* x <- 2
608
609        *)
610        | Pexp_override of (Asttypes.label Asttypes.loc * expression) list
611         (* {< x1 = E1; ...; xn = En >}
612
613        *)
614        | Pexp_letmodule of string option Asttypes.loc * module_expr * expres‐
615       sion
616         (* let module M = ME in E
617
618        *)
619        | Pexp_letexception of extension_constructor * expression
620         (* let exception C in E
621
622        *)
623        | Pexp_assert of expression
624         (* assert E .
625
626       Note: assert false is treated in a special way by the type-checker.
627        *)
628        | Pexp_lazy of expression
629         (* lazy E
630
631        *)
632        | Pexp_poly of expression * core_type option
633         (* Used for method bodies.
634
635       Can    only    be    used    as    the    expression    under    Parse‐
636       tree.class_field_kind.Cfk_concrete for methods (not values).
637        *)
638        | Pexp_object of class_structure
639         (* object ... end
640
641        *)
642        | Pexp_newtype of string Asttypes.loc * expression
643         (* fun (type t) -> E
644
645        *)
646        | Pexp_pack of module_expr
647         (* (module ME) .
648
649
650       (module  ME  :  S)  is  represented  as  Pexp_constraint(Pexp_pack  ME,
651       Ptyp_package S)
652
653        *)
654        | Pexp_open of open_declaration * expression
655         (* - M.(E)
656
657       - let open M in E
658
659
660       - let open! M in E
661
662
663        *)
664        | Pexp_letop of letop
665         (* - let* P = E0 in E1
666
667       - let* P0 = E00 and* P1 = E01 in E1
668
669
670        *)
671        | Pexp_extension of extension
672         (* [%id]
673
674        *)
675        | Pexp_unreachable  (* .
676
677        *)
678
679
680
681
682       type case = {
683        pc_lhs : pattern ;
684        pc_guard : expression option ;
685        pc_rhs : expression ;
686        }
687
688
689       Values of type Parsetree.case represents (P -> E) or (P when E0 -> E)
690
691
692
693       type letop = {
694        let_ : binding_op ;
695        ands : binding_op list ;
696        body : expression ;
697        }
698
699
700
701
702       type binding_op = {
703        pbop_op : string Asttypes.loc ;
704        pbop_pat : pattern ;
705        pbop_exp : expression ;
706        pbop_loc : Location.t ;
707        }
708
709
710
711
712
713
714   Value descriptions
715       type value_description = {
716        pval_name : string Asttypes.loc ;
717        pval_type : core_type ;
718        pval_prim : string list ;
719        pval_attributes : attributes ;  (* ... [@@id1] [@@id2]
720
721        *)
722        pval_loc : Location.t ;
723        }
724
725
726       Values of type Parsetree.value_description represents:
727
728       - val x: T , when Parsetree.value_description.pval_prim is []
729
730
731       -  external  x:  T  =  "s1"  ...  "sn"  when   Parsetree.value_descrip‐
732       tion.pval_prim is ["s1";..."sn"]
733
734
735
736
737
738
739   Type declarations
740       type type_declaration = {
741        ptype_name : string Asttypes.loc ;
742        ptype_params  :  (core_type  * (Asttypes.variance * Asttypes.injectiv‐
743       ity)) list ;  (* ('a1,...'an) t
744
745        *)
746        ptype_cstrs : (core_type * core_type * Location.t) list ;  (* ... con‐
747       straint T1=T1'  ... constraint Tn=Tn'
748
749        *)
750        ptype_kind : type_kind ;
751        ptype_private : Asttypes.private_flag ;  (* for = private ...
752
753        *)
754        ptype_manifest : core_type option ;  (* represents = T
755
756        *)
757        ptype_attributes : attributes ;  (* ... [@@id1] [@@id2]
758
759        *)
760        ptype_loc : Location.t ;
761        }
762
763
764       Here are type declarations and their representation, for various Parse‐
765       tree.type_declaration.ptype_kind      and       Parsetree.type_declara‐
766       tion.ptype_manifest values:
767
768       -  type  t  when  type_kind is Parsetree.type_kind.Ptype_abstract , and
769       manifest is None ,
770
771       - type t = T0 when type_kind  is  Parsetree.type_kind.Ptype_abstract  ,
772       and manifest is Some T0 ,
773
774       -   type   t   =   C   of   T   |   ...    when   type_kind  is  Parse‐
775       tree.type_kind.Ptype_variant , and manifest is None ,
776
777       -  type  t  =  T0  =  C  of  T  |  ...   when   type_kind   is   Parse‐
778       tree.type_kind.Ptype_variant , and manifest is Some T0 ,
779
780       -    type    t    =    {l:   T;   ...}   when   type_kind   is   Parse‐
781       tree.type_kind.Ptype_record , and manifest is None ,
782
783       -  type  t  =  T0  =  {l  :  T;   ...}   when   type_kind   is   Parse‐
784       tree.type_kind.Ptype_record , and manifest is Some T0 ,
785
786       -  type  t = ..  when type_kind is Parsetree.type_kind.Ptype_open , and
787       manifest is None .
788
789
790
791       type type_kind =
792        | Ptype_abstract
793        | Ptype_variant of constructor_declaration list
794        | Ptype_record of label_declaration list
795         (* Invariant: non-empty list
796        *)
797        | Ptype_open
798
799
800
801
802       type label_declaration = {
803        pld_name : string Asttypes.loc ;
804        pld_mutable : Asttypes.mutable_flag ;
805        pld_type : core_type ;
806        pld_loc : Location.t ;
807        pld_attributes : attributes ;  (* l : T [@id1] [@id2]
808
809        *)
810        }
811
812
813       - { ...; l: T; ... }  when  Parsetree.label_declaration.pld_mutable  is
814       Asttypes.mutable_flag.Immutable ,
815
816       - { ...; mutable l: T; ... } when Parsetree.label_declaration.pld_muta‐
817       ble is Asttypes.mutable_flag.Mutable .
818
819       Note: T can be a Parsetree.core_type_desc.Ptyp_poly .
820
821
822       type constructor_declaration = {
823        pcd_name : string Asttypes.loc ;
824        pcd_vars : string Asttypes.loc list ;
825        pcd_args : constructor_arguments ;
826        pcd_res : core_type option ;
827        pcd_loc : Location.t ;
828        pcd_attributes : attributes ;  (* C of ... [@id1] [@id2]
829
830        *)
831        }
832
833
834
835
836       type constructor_arguments =
837        | Pcstr_tuple of core_type list
838        | Pcstr_record of label_declaration list
839         (* Values of type  Parsetree.constructor_declaration  represents  the
840       constructor arguments of:
841
842       -  C of T1 * ... * Tn when res = None , and args = Pcstr_tuple [T1; ...
843       ; Tn] ,
844
845       - C: T0 when res = Some T0 , and args = Pcstr_tuple [] ,
846
847       - C: T1 * ... * Tn -> T0 when res = Some T0 , and  args  =  Pcstr_tuple
848       [T1; ... ; Tn] ,
849
850       - C of {...} when res = None , and args = Pcstr_record [...]  ,
851
852       - C: {...} -> T0 when res = Some T0 , and args = Pcstr_record [...]  .
853
854        *)
855
856
857
858
859       type type_extension = {
860        ptyext_path : Longident.t Asttypes.loc ;
861        ptyext_params  :  (core_type * (Asttypes.variance * Asttypes.injectiv‐
862       ity)) list ;
863        ptyext_constructors : extension_constructor list ;
864        ptyext_private : Asttypes.private_flag ;
865        ptyext_loc : Location.t ;
866        ptyext_attributes : attributes ;  (* ...  @@id1 @@id2
867
868        *)
869        }
870
871
872       Definition of new extensions constructors for the extensive sum type  t
873       ( type t += ...  ).
874
875
876       type extension_constructor = {
877        pext_name : string Asttypes.loc ;
878        pext_kind : extension_constructor_kind ;
879        pext_loc : Location.t ;
880        pext_attributes : attributes ;  (* C of ... [@id1] [@id2]
881
882        *)
883        }
884
885
886
887
888       type type_exception = {
889        ptyexn_constructor : extension_constructor ;
890        ptyexn_loc : Location.t ;
891        ptyexn_attributes : attributes ;  (* ... [@@id1] [@@id2]
892
893        *)
894        }
895
896
897       Definition of a new exception ( exception E ).
898
899
900       type extension_constructor_kind =
901        |  Pext_decl  of  string  Asttypes.loc  list * constructor_arguments *
902       core_type option
903         (* Pext_decl(existentials, c_args, t_opt) describes a  new  extension
904       constructor. It can be:
905
906       - C of T1 * ... * Tn when:
907
908       - existentials is [] ,
909
910       - c_args is [T1; ...; Tn] ,
911
912       - t_opt is None
913
914
915
916       - C: T0 when
917
918       - existentials is [] ,
919
920       - c_args is [] ,
921
922       - t_opt is Some T0 .
923
924
925       - C: T1 * ... * Tn -> T0 when
926
927       - existentials is [] ,
928
929       - c_args is [T1; ...; Tn] ,
930
931       - t_opt is Some T0 .
932
933
934       - C: 'a... . T1 * ... * Tn -> T0 when
935
936       - existentials is ['a;...]  ,
937
938       - c_args is [T1; ... ; Tn] ,
939
940       - t_opt is Some T0 .
941
942
943        *)
944        | Pext_rebind of Longident.t Asttypes.loc
945         (* Pext_rebind(D) re-export the constructor D with the new name C
946
947        *)
948
949
950
951
952
953
954   Class language
955   Type expressions for the class language
956       type class_type = {
957        pcty_desc : class_type_desc ;
958        pcty_loc : Location.t ;
959        pcty_attributes : attributes ;  (* ... [@id1] [@id2]
960
961        *)
962        }
963
964
965
966
967       type class_type_desc =
968        | Pcty_constr of Longident.t Asttypes.loc * core_type list
969         (* - c
970
971       - ['a1, ..., 'an] c
972
973
974        *)
975        | Pcty_signature of class_signature
976         (* object ... end
977
978        *)
979        | Pcty_arrow of Asttypes.arg_label * core_type * class_type
980         (* Pcty_arrow(lbl, T, CT) represents:
981
982       - T -> CT when lbl is Asttypes.arg_label.Nolabel ,
983
984       - ~l:T -> CT when lbl is Asttypes.arg_label.Labelled ,
985
986       - ?l:T -> CT when lbl is Asttypes.arg_label.Optional .
987
988        *)
989        | Pcty_extension of extension
990         (* %id
991
992        *)
993        | Pcty_open of open_description * class_type
994         (* let open M in CT
995
996        *)
997
998
999
1000
1001       type class_signature = {
1002        pcsig_self : core_type ;
1003        pcsig_fields : class_type_field list ;
1004        }
1005
1006
1007       Values of type class_signature represents:
1008
1009       - object('selfpat) ... end
1010
1011
1012       -  object  ...  end when Parsetree.class_signature.pcsig_self is Parse‐
1013       tree.core_type_desc.Ptyp_any
1014
1015
1016
1017
1018       type class_type_field = {
1019        pctf_desc : class_type_field_desc ;
1020        pctf_loc : Location.t ;
1021        pctf_attributes : attributes ;  (* ... [@@id1] [@@id2]
1022
1023        *)
1024        }
1025
1026
1027
1028
1029       type class_type_field_desc =
1030        | Pctf_inherit of class_type
1031         (* inherit CT
1032
1033        *)
1034        | Pctf_val of (Asttypes.label Asttypes.loc *  Asttypes.mutable_flag  *
1035       Asttypes.virtual_flag * core_type)
1036         (* val x: T
1037
1038        *)
1039        |  Pctf_method of (Asttypes.label Asttypes.loc * Asttypes.private_flag
1040       * Asttypes.virtual_flag * core_type)
1041         (* method x: T
1042
1043       Note: T can be a Parsetree.core_type_desc.Ptyp_poly .
1044        *)
1045        | Pctf_constraint of (core_type * core_type)
1046         (* constraint T1 = T2
1047
1048        *)
1049        | Pctf_attribute of attribute
1050         (* [@@@id]
1051
1052        *)
1053        | Pctf_extension of extension
1054         (* [%%id]
1055
1056        *)
1057
1058
1059
1060
1061       type 'a class_infos = {
1062        pci_virt : Asttypes.virtual_flag ;
1063        pci_params : (core_type * (Asttypes.variance *  Asttypes.injectivity))
1064       list ;
1065        pci_name : string Asttypes.loc ;
1066        pci_expr : 'a ;
1067        pci_loc : Location.t ;
1068        pci_attributes : attributes ;  (* ... [@@id1] [@@id2]
1069
1070        *)
1071        }
1072
1073
1074       Values of type class_expr class_infos represents:
1075
1076       - class c = ...
1077
1078
1079       - class ['a1,...,'an] c = ...
1080
1081
1082       - class virtual c = ...
1083
1084       They are also used for "class type" declaration.
1085
1086
1087       type class_description = class_type class_infos
1088
1089
1090
1091
1092       type class_type_declaration = class_type class_infos
1093
1094
1095
1096
1097
1098
1099   Value expressions for the class language
1100       type class_expr = {
1101        pcl_desc : class_expr_desc ;
1102        pcl_loc : Location.t ;
1103        pcl_attributes : attributes ;  (* ... [@id1] [@id2]
1104
1105        *)
1106        }
1107
1108
1109
1110
1111       type class_expr_desc =
1112        | Pcl_constr of Longident.t Asttypes.loc * core_type list
1113         (* c and ['a1, ..., 'an] c
1114
1115        *)
1116        | Pcl_structure of class_structure
1117         (* object ... end
1118
1119        *)
1120        |  Pcl_fun  of  Asttypes.arg_label  *  expression  option  * pattern *
1121       class_expr
1122         (* Pcl_fun(lbl, exp0, P, CE) represents:
1123
1124       - fun P -> CE when lbl is Asttypes.arg_label.Nolabel and exp0 is None ,
1125
1126       - fun ~l:P -> CE when lbl is Asttypes.arg_label.Labelled  and  exp0  is
1127       None ,
1128
1129       -  fun  ?l:P  -> CE when lbl is Asttypes.arg_label.Optional and exp0 is
1130       None ,
1131
1132       - fun ?l:(P = E0) -> CE when  lbl  is  Asttypes.arg_label.Optional  and
1133       exp0 is Some E0 .
1134
1135        *)
1136        | Pcl_apply of class_expr * (Asttypes.arg_label * expression) list
1137         (*  Pcl_apply(CE, [(l1,E1) ; ... ; (ln,En)]) represents CE ~l1:E1 ...
1138       ~ln:En .  li can be empty (non labeled argument) or start with ?   (op‐
1139       tional argument).
1140
1141       Invariant: n > 0
1142
1143        *)
1144        | Pcl_let of Asttypes.rec_flag * value_binding list * class_expr
1145         (* Pcl_let(rec, [(P1, E1); ... ; (Pn, En)], CE) represents:
1146
1147       -  let  P1  =  E1  and  ...  and  Pn  =  EN  in  CE  when  rec  is Ast‐
1148       types.rec_flag.Nonrecursive ,
1149
1150       - let rec P1 = E1 and  ...  and  Pn  =  EN  in  CE  when  rec  is  Ast‐
1151       types.rec_flag.Recursive .
1152
1153        *)
1154        | Pcl_constraint of class_expr * class_type
1155         (* (CE : CT)
1156
1157        *)
1158        | Pcl_extension of extension
1159         (* [%id]
1160
1161        *)
1162        | Pcl_open of open_description * class_expr
1163         (* let open M in CE
1164
1165        *)
1166
1167
1168
1169
1170       type class_structure = {
1171        pcstr_self : pattern ;
1172        pcstr_fields : class_field list ;
1173        }
1174
1175
1176       Values of type Parsetree.class_structure represents:
1177
1178       - object(selfpat) ... end
1179
1180
1181       -  object  ...  end when Parsetree.class_structure.pcstr_self is Parse‐
1182       tree.pattern_desc.Ppat_any
1183
1184
1185
1186
1187       type class_field = {
1188        pcf_desc : class_field_desc ;
1189        pcf_loc : Location.t ;
1190        pcf_attributes : attributes ;  (* ... [@@id1] [@@id2]
1191
1192        *)
1193        }
1194
1195
1196
1197
1198       type class_field_desc =
1199        | Pcf_inherit of Asttypes.override_flag *  class_expr  *  string  Ast‐
1200       types.loc option
1201         (* Pcf_inherit(flag, CE, s) represents:
1202
1203       - inherit CE when flag is Asttypes.override_flag.Fresh and s is None ,
1204
1205       -  inherit  CE  as x when flag is Asttypes.override_flag.Fresh and s is
1206       Some x ,
1207
1208       - inherit! CE when flag is  Asttypes.override_flag.Override  and  s  is
1209       None ,
1210
1211       -  inherit!  CE as x when flag is Asttypes.override_flag.Override and s
1212       is Some x
1213
1214
1215        *)
1216        | Pcf_val of (Asttypes.label Asttypes.loc  *  Asttypes.mutable_flag  *
1217       class_field_kind)
1218         (* Pcf_val(x,flag, kind) represents:
1219
1220       -  val  x  = E when flag is Asttypes.mutable_flag.Immutable and kind is
1221       Parsetree.class_field_kind.Cfk_concrete
1222
1223
1224       - val virtual x: T when  flag  is  Asttypes.mutable_flag.Immutable  and
1225       kind is Parsetree.class_field_kind.Cfk_virtual
1226
1227
1228       - val mutable x = E when flag is Asttypes.mutable_flag.Mutable and kind
1229       is Parsetree.class_field_kind.Cfk_concrete
1230
1231
1232       - val mutable virtual x: T when flag  is  Asttypes.mutable_flag.Mutable
1233       and kind is Parsetree.class_field_kind.Cfk_virtual
1234
1235
1236        *)
1237        | Pcf_method of (Asttypes.label Asttypes.loc * Asttypes.private_flag *
1238       class_field_kind)
1239         (* - method x = E ( E can be a Parsetree.expression_desc.Pexp_poly )
1240
1241       - method virtual x: T ( T can be a Parsetree.core_type_desc.Ptyp_poly )
1242
1243        *)
1244        | Pcf_constraint of (core_type * core_type)
1245         (* constraint T1 = T2
1246
1247        *)
1248        | Pcf_initializer of expression
1249         (* initializer E
1250
1251        *)
1252        | Pcf_attribute of attribute
1253         (* [@@@id]
1254
1255        *)
1256        | Pcf_extension of extension
1257         (* [%%id]
1258
1259        *)
1260
1261
1262
1263
1264       type class_field_kind =
1265        | Cfk_virtual of core_type
1266        | Cfk_concrete of Asttypes.override_flag * expression
1267
1268
1269
1270
1271       type class_declaration = class_expr class_infos
1272
1273
1274
1275
1276
1277
1278   Module language
1279   Type expressions for the module language
1280       type module_type = {
1281        pmty_desc : module_type_desc ;
1282        pmty_loc : Location.t ;
1283        pmty_attributes : attributes ;  (* ... [@id1] [@id2]
1284
1285        *)
1286        }
1287
1288
1289
1290
1291       type module_type_desc =
1292        | Pmty_ident of Longident.t Asttypes.loc
1293         (* Pmty_ident(S) represents S
1294
1295        *)
1296        | Pmty_signature of signature
1297         (* sig ... end
1298
1299        *)
1300        | Pmty_functor of functor_parameter * module_type
1301         (* functor(X : MT1) -> MT2
1302
1303        *)
1304        | Pmty_with of module_type * with_constraint list
1305         (* MT with ...
1306
1307        *)
1308        | Pmty_typeof of module_expr
1309         (* module type of ME
1310
1311        *)
1312        | Pmty_extension of extension
1313         (* [%id]
1314
1315        *)
1316        | Pmty_alias of Longident.t Asttypes.loc
1317         (* (module M)
1318
1319        *)
1320
1321
1322
1323
1324       type functor_parameter =
1325        | Unit  (* ()
1326
1327        *)
1328        | Named of string option Asttypes.loc * module_type
1329         (* Named(name, MT) represents:
1330
1331       - (X : MT) when name is Some X ,
1332
1333       - (_ : MT) when name is None
1334
1335
1336        *)
1337
1338
1339
1340
1341       type signature = signature_item list
1342
1343
1344
1345
1346       type signature_item = {
1347        psig_desc : signature_item_desc ;
1348        psig_loc : Location.t ;
1349        }
1350
1351
1352
1353
1354       type signature_item_desc =
1355        | Psig_value of value_description
1356         (* - val x: T
1357
1358       - external x: T = "s1" ... "sn"
1359
1360
1361        *)
1362        | Psig_type of Asttypes.rec_flag * type_declaration list
1363         (* type t1 = ... and ... and tn  = ...
1364
1365        *)
1366        | Psig_typesubst of type_declaration list
1367         (* type t1 := ... and ... and tn := ...
1368
1369        *)
1370        | Psig_typext of type_extension
1371         (* type t1 += ...
1372
1373        *)
1374        | Psig_exception of type_exception
1375         (* exception C of T
1376
1377        *)
1378        | Psig_module of module_declaration
1379         (* module X = M and module X : MT
1380
1381        *)
1382        | Psig_modsubst of module_substitution
1383         (* module X := M
1384
1385        *)
1386        | Psig_recmodule of module_declaration list
1387         (* module rec X1 : MT1 and ... and Xn : MTn
1388
1389        *)
1390        | Psig_modtype of module_type_declaration
1391         (* module type S = MT and module type S
1392
1393        *)
1394        | Psig_modtypesubst of module_type_declaration
1395         (* module type S :=  ...
1396
1397        *)
1398        | Psig_open of open_description
1399         (* open X
1400
1401        *)
1402        | Psig_include of include_description
1403         (* include MT
1404
1405        *)
1406        | Psig_class of class_description list
1407         (* class c1 : ... and ... and cn : ...
1408
1409        *)
1410        | Psig_class_type of class_type_declaration list
1411         (* class type ct1 = ... and ... and ctn = ...
1412
1413        *)
1414        | Psig_attribute of attribute
1415         (* [@@@id]
1416
1417        *)
1418        | Psig_extension of extension * attributes
1419         (* [%%id]
1420
1421        *)
1422
1423
1424
1425
1426       type module_declaration = {
1427        pmd_name : string option Asttypes.loc ;
1428        pmd_type : module_type ;
1429        pmd_attributes : attributes ;  (* ... [@@id1] [@@id2]
1430
1431        *)
1432        pmd_loc : Location.t ;
1433        }
1434
1435
1436       Values of type module_declaration represents S : MT
1437
1438
1439
1440       type module_substitution = {
1441        pms_name : string Asttypes.loc ;
1442        pms_manifest : Longident.t Asttypes.loc ;
1443        pms_attributes : attributes ;  (* ... [@@id1] [@@id2]
1444
1445        *)
1446        pms_loc : Location.t ;
1447        }
1448
1449
1450       Values of type module_substitution represents S := M
1451
1452
1453
1454       type module_type_declaration = {
1455        pmtd_name : string Asttypes.loc ;
1456        pmtd_type : module_type option ;
1457        pmtd_attributes : attributes ;  (* ... [@@id1] [@@id2]
1458
1459        *)
1460        pmtd_loc : Location.t ;
1461        }
1462
1463
1464       Values of type module_type_declaration represents:
1465
1466       - S = MT ,
1467
1468       -  S  for  abstract  module  type  declaration,   when   Parsetree.mod‐
1469       ule_type_declaration.pmtd_type is None .
1470
1471
1472
1473       type 'a open_infos = {
1474        popen_expr : 'a ;
1475        popen_override : Asttypes.override_flag ;
1476        popen_loc : Location.t ;
1477        popen_attributes : attributes ;
1478        }
1479
1480
1481       Values of type 'a open_infos represents:
1482
1483       -  open!  X  when Parsetree.open_infos.popen_override is Asttypes.over‐
1484       ride_flag.Override (silences the "used identifier shadowing" warning)
1485
1486       - open  X when  Parsetree.open_infos.popen_override  is  Asttypes.over‐
1487       ride_flag.Fresh
1488
1489
1490
1491
1492       type open_description = Longident.t Asttypes.loc open_infos
1493
1494
1495       Values of type open_description represents:
1496
1497       - open M.N
1498
1499
1500       - open M(N).O
1501
1502
1503
1504
1505       type open_declaration = module_expr open_infos
1506
1507
1508       Values of type open_declaration represents:
1509
1510       - open M.N
1511
1512
1513       - open M(N).O
1514
1515
1516       - open struct ... end
1517
1518
1519
1520
1521       type 'a include_infos = {
1522        pincl_mod : 'a ;
1523        pincl_loc : Location.t ;
1524        pincl_attributes : attributes ;
1525        }
1526
1527
1528
1529
1530       type include_description = module_type include_infos
1531
1532
1533       Values of type include_description represents include MT
1534
1535
1536
1537       type include_declaration = module_expr include_infos
1538
1539
1540       Values of type include_declaration represents include ME
1541
1542
1543
1544       type with_constraint =
1545        | Pwith_type of Longident.t Asttypes.loc * type_declaration
1546         (* with type X.t = ...
1547
1548       Note:  the  last  component of the longident must match the name of the
1549       type_declaration.
1550        *)
1551        | Pwith_module of Longident.t Asttypes.loc * Longident.t Asttypes.loc
1552         (* with module X.Y = Z
1553
1554        *)
1555        | Pwith_modtype of Longident.t Asttypes.loc * module_type
1556         (* with module type X.Y = Z
1557
1558        *)
1559        | Pwith_modtypesubst of Longident.t Asttypes.loc * module_type
1560         (* with module type X.Y := sig end
1561
1562        *)
1563        | Pwith_typesubst of Longident.t Asttypes.loc * type_declaration
1564         (* with type X.t := ..., same format as [Pwith_type]
1565
1566        *)
1567        |  Pwith_modsubst  of  Longident.t  Asttypes.loc  *  Longident.t  Ast‐
1568       types.loc
1569         (* with module X.Y := Z
1570
1571        *)
1572
1573
1574
1575
1576
1577
1578   Value expressions for the module language
1579       type module_expr = {
1580        pmod_desc : module_expr_desc ;
1581        pmod_loc : Location.t ;
1582        pmod_attributes : attributes ;  (* ... [@id1] [@id2]
1583
1584        *)
1585        }
1586
1587
1588
1589
1590       type module_expr_desc =
1591        | Pmod_ident of Longident.t Asttypes.loc
1592         (* X
1593
1594        *)
1595        | Pmod_structure of structure
1596         (* struct ... end
1597
1598        *)
1599        | Pmod_functor of functor_parameter * module_expr
1600         (* functor(X : MT1) -> ME
1601
1602        *)
1603        | Pmod_apply of module_expr * module_expr
1604         (* ME1(ME2)
1605
1606        *)
1607        | Pmod_constraint of module_expr * module_type
1608         (* (ME : MT)
1609
1610        *)
1611        | Pmod_unpack of expression
1612         (* (val E)
1613
1614        *)
1615        | Pmod_extension of extension
1616         (* [%id]
1617
1618        *)
1619
1620
1621
1622
1623       type structure = structure_item list
1624
1625
1626
1627
1628       type structure_item = {
1629        pstr_desc : structure_item_desc ;
1630        pstr_loc : Location.t ;
1631        }
1632
1633
1634
1635
1636       type structure_item_desc =
1637        | Pstr_eval of expression * attributes
1638         (* E
1639
1640        *)
1641        | Pstr_value of Asttypes.rec_flag * value_binding list
1642         (* Pstr_value(rec, [(P1, E1 ; ... ; (Pn, En))]) represents:
1643
1644       -  let P1 = E1 and ... and Pn = EN when rec is Asttypes.rec_flag.Nonre‐
1645       cursive ,
1646
1647       - let rec P1 = E1 and ... and Pn = EN when rec is Asttypes.rec_flag.Re‐
1648       cursive .
1649
1650        *)
1651        | Pstr_primitive of value_description
1652         (* - val x: T
1653
1654       - external x: T = "s1" ... "sn"
1655
1656
1657        *)
1658        | Pstr_type of Asttypes.rec_flag * type_declaration list
1659         (* type t1 = ... and ... and tn = ...
1660
1661        *)
1662        | Pstr_typext of type_extension
1663         (* type t1 += ...
1664
1665        *)
1666        | Pstr_exception of type_exception
1667         (* - exception C of T
1668
1669       - exception C = M.X
1670
1671
1672        *)
1673        | Pstr_module of module_binding
1674         (* module X = ME
1675
1676        *)
1677        | Pstr_recmodule of module_binding list
1678         (* module rec X1 = ME1 and ... and Xn = MEn
1679
1680        *)
1681        | Pstr_modtype of module_type_declaration
1682         (* module type S = MT
1683
1684        *)
1685        | Pstr_open of open_declaration
1686         (* open X
1687
1688        *)
1689        | Pstr_class of class_declaration list
1690         (* class c1 = ... and ... and cn = ...
1691
1692        *)
1693        | Pstr_class_type of class_type_declaration list
1694         (* class type ct1 = ... and ... and ctn = ...
1695
1696        *)
1697        | Pstr_include of include_declaration
1698         (* include ME
1699
1700        *)
1701        | Pstr_attribute of attribute
1702         (* [@@@id]
1703
1704        *)
1705        | Pstr_extension of extension * attributes
1706         (* [%%id]
1707
1708        *)
1709
1710
1711
1712
1713       type value_binding = {
1714        pvb_pat : pattern ;
1715        pvb_expr : expression ;
1716        pvb_attributes : attributes ;
1717        pvb_loc : Location.t ;
1718        }
1719
1720
1721
1722
1723       type module_binding = {
1724        pmb_name : string option Asttypes.loc ;
1725        pmb_expr : module_expr ;
1726        pmb_attributes : attributes ;
1727        pmb_loc : Location.t ;
1728        }
1729
1730
1731       Values of type module_binding represents module X = ME
1732
1733
1734
1735
1736
1737   Toplevel
1738   Toplevel phrases
1739       type toplevel_phrase =
1740        | Ptop_def of structure
1741        | Ptop_dir of toplevel_directive
1742         (* #use , #load ...
1743        *)
1744
1745
1746
1747
1748       type toplevel_directive = {
1749        pdir_name : string Asttypes.loc ;
1750        pdir_arg : directive_argument option ;
1751        pdir_loc : Location.t ;
1752        }
1753
1754
1755
1756
1757       type directive_argument = {
1758        pdira_desc : directive_argument_desc ;
1759        pdira_loc : Location.t ;
1760        }
1761
1762
1763
1764
1765       type directive_argument_desc =
1766        | Pdir_string of string
1767        | Pdir_int of string * char option
1768        | Pdir_ident of Longident.t
1769        | Pdir_bool of bool
1770
1771
1772
1773
1774
1775
1776
1777OCamldoc                          2023-07-20                      Parsetree(3)