Module Parsetree

module Parsetree: sig .. end

Abstract syntax tree produced by parsing

Warning: this module is unstable and part of compiler-libs.

type constant =
| Pconst_integer of string * char option (*

Integer constants such as 3 3l 3L 3n.

Suffixes [g-z][G-Z] are accepted by the parser. Suffixes except 'l', 'L' and 'n' are rejected by the typechecker

*)
| Pconst_char of char (*

Character such as 'c'.

*)
| Pconst_string of string * Location.t * string option (*

Constant string such as "constant" or {delim|other constant|delim}.

The location span the content of the string, without the delimiters.

*)
| Pconst_float of string * char option (*

Float constant such as 3.4, 2e5 or 1.4e-4.

Suffixes g-zG-Z are accepted by the parser. Suffixes are rejected by the typechecker.

*) 
type location_stack = Location.t list

Extension points

type attribute = {
   attr_name : string Asttypes.loc;
   attr_payload : payload;
   attr_loc : Location.t;
}

Attributes such as [@id ARG] and [@@id ARG].

Metadata containers passed around within the AST. The compiler ignores unknown attributes.

type extension = string Asttypes.loc * payload

Extension points such as [%id ARG] and [%%id ARG].

Sub-language placeholder -- rejected by the typechecker.

type attributes = attribute list 
type payload =
| PStr of structure
| PSig of signature (*

: SIG in an attribute or an extension point

*)
| PTyp of core_type (*

: T in an attribute or an extension point

*)
| PPat of pattern * expression option (*

? P or ? P when E, in an attribute or an extension point

*)

Core language

Type expressions

type core_type = {
   ptyp_desc : core_type_desc;
   ptyp_loc : Location.t;
   ptyp_loc_stack : location_stack;
   ptyp_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type core_type_desc =
| Ptyp_any (*

_

*)
| Ptyp_var of string (*

A type variable such as 'a

*)
| Ptyp_arrow of Asttypes.arg_label * core_type * core_type (*

Ptyp_arrow(lbl, T1, T2) represents:

*)
| Ptyp_tuple of core_type list (*

Ptyp_tuple([T1 ; ... ; Tn]) represents a product type T1 * ... * Tn.

Invariant: n >= 2.

*)
| Ptyp_constr of Longident.t Asttypes.loc * core_type list (*

Ptyp_constr(lident, l) represents:

  • tconstr when l=[],
  • T tconstr when l=[T],
  • (T1, ..., Tn) tconstr when l=[T1 ; ... ; Tn].
*)
| Ptyp_object of object_field list * Asttypes.closed_flag (*

Ptyp_object([ l1:T1; ...; ln:Tn ], flag) represents:

  • < l1:T1; ...; ln:Tn > when flag is Closed,
  • < l1:T1; ...; ln:Tn; .. > when flag is Open.
*)
| Ptyp_class of Longident.t Asttypes.loc * core_type list (*

Ptyp_class(tconstr, l) represents:

  • #tconstr when l=[],
  • T #tconstr when l=[T],
  • (T1, ..., Tn) #tconstr when l=[T1 ; ... ; Tn].
*)
| Ptyp_alias of core_type * string Asttypes.loc (*

T as 'a.

*)
| Ptyp_variant of row_field list * Asttypes.closed_flag * Asttypes.label list option (*

Ptyp_variant([`A;`B], flag, labels) represents:

  • [ `A|`B ] when flag is Closed, and labels is None,
  • [> `A|`B ] when flag is Open, and labels is None,
  • [< `A|`B ] when flag is Closed, and labels is Some [],
  • [< `A|`B > `X `Y ] when flag is Closed, and labels is Some ["X";"Y"].
*)
| Ptyp_poly of string Asttypes.loc list * core_type (*

'a1 ... 'an. T

Can only appear in the following context:

*)
| Ptyp_package of package_type (*

(module S).

*)
| Ptyp_open of Longident.t Asttypes.loc * core_type (*

M.(T)

*)
| Ptyp_extension of extension (*

[%id].

*) 
type package_type = Longident.t Asttypes.loc *
       (Longident.t Asttypes.loc * core_type) list

As Parsetree.package_type typed values:

  • (S, []) represents (module S),
  • (S, [(t1, T1) ; ... ; (tn, Tn)]) represents (module S with type t1 = T1 and ... and tn = Tn).
type row_field = {
   prf_desc : row_field_desc;
   prf_loc : Location.t;
   prf_attributes : attributes;
} 
type row_field_desc =
| Rtag of Asttypes.label Asttypes.loc * bool * core_type list (*

Rtag(`A, b, l) represents:

  • `A when b is true and l is [],
  • `A of T when b is false and l is [T],
  • `A of T1 & .. & Tn when b is false and l is [T1;...Tn],
  • `A of & T1 & .. & Tn when b is true and l is [T1;...Tn].
  • The bool field is true if the tag contains a constant (empty) constructor.
  • & occurs when several types are used for the same constructor (see 4.2 in the manual)
*)
| Rinherit of core_type (*

[ | t ]

*) 
type object_field = {
   pof_desc : object_field_desc;
   pof_loc : Location.t;
   pof_attributes : attributes;
} 
type object_field_desc =
| Otag of Asttypes.label Asttypes.loc * core_type
| Oinherit of core_type

Patterns

type pattern = {
   ppat_desc : pattern_desc;
   ppat_loc : Location.t;
   ppat_loc_stack : location_stack;
   ppat_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type pattern_desc =
| Ppat_any (*

The pattern _.

*)
| Ppat_var of string Asttypes.loc (*

A variable pattern such as x

*)
| Ppat_alias of pattern * string Asttypes.loc (*

An alias pattern such as P as 'a

*)
| Ppat_constant of constant (*

Patterns such as 1, 'a', "true", 1.0, 1l, 1L, 1n

*)
| Ppat_interval of constant * constant (*

Patterns such as 'a'..'z'.

Other forms of interval are recognized by the parser but rejected by the type-checker.

*)
| Ppat_tuple of pattern list (*

Patterns (P1, ..., Pn).

Invariant: n >= 2

*)
| Ppat_construct of Longident.t Asttypes.loc
* (string Asttypes.loc list * pattern) option		 (*

Ppat_construct(C, args) represents:

  • C when args is None,
  • C P when args is Some ([], P)
  • C (P1, ..., Pn) when args is Some ([], Ppat_tuple [P1; ...; Pn])
  • C (type a b) P when args is Some ([a; b], P)
*)
| Ppat_variant of Asttypes.label * pattern option (*

Ppat_variant(`A, pat) represents:

  • `A when pat is None,
  • `A P when pat is Some P
*)
| Ppat_record of (Longident.t Asttypes.loc * pattern) list * Asttypes.closed_flag (*

Ppat_record([(l1, P1) ; ... ; (ln, Pn)], flag) represents:

  • { l1=P1; ...; ln=Pn } when flag is Closed
  • { l1=P1; ...; ln=Pn; _} when flag is Open

Invariant: n > 0

*)
| Ppat_array of pattern list (*

Pattern [| P1; ...; Pn |]

*)
| Ppat_or of pattern * pattern (*

Pattern P1 | P2

*)
| Ppat_constraint of pattern * core_type (*

Pattern (P : T)

*)
| Ppat_type of Longident.t Asttypes.loc (*

Pattern #tconst

*)
| Ppat_lazy of pattern (*

Pattern lazy P

*)
| Ppat_unpack of string option Asttypes.loc (*

Ppat_unpack(s) represents:

  • (module P) when s is Some "P"
  • (module _) when s is None

Note: (module P : S) is represented as Ppat_constraint(Ppat_unpack(Some "P"), Ptyp_package S)

*)
| Ppat_exception of pattern (*

Pattern exception P

*)
| Ppat_extension of extension (*

Pattern [%id]

*)
| Ppat_open of Longident.t Asttypes.loc * pattern (*

Pattern M.(P)

*)

Value expressions

type expression = {
   pexp_desc : expression_desc;
   pexp_loc : Location.t;
   pexp_loc_stack : location_stack;
   pexp_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type expression_desc =
| Pexp_ident of Longident.t Asttypes.loc (*

Identifiers such as x and M.x

*)
| Pexp_constant of constant (*

Expressions constant such as 1, 'a', "true", 1.0, 1l, 1L, 1n

*)
| Pexp_let of Asttypes.rec_flag * value_binding list * expression (*

Pexp_let(flag, [(P1,E1) ; ... ; (Pn,En)], E) represents:

  • let P1 = E1 and ... and Pn = EN in E when flag is Nonrecursive,
  • let rec P1 = E1 and ... and Pn = EN in E when flag is Recursive.
*)
| Pexp_function of function_param list * type_constraint option
* function_body		 (*

Pexp_function ([P1; ...; Pn], C, body) represents any construct involving fun or function, including:

  • fun P1 ... Pn -> E when body = Pfunction_body E
  • fun P1 ... Pn -> function p1 -> e1 | ... | pm -> em when body = Pfunction_cases [ p1 -> e1; ...; pm -> em ]

C represents a type constraint or coercion placed immediately before the arrow, e.g. fun P1 ... Pn : ty -> ... when C = Some (Pconstraint ty).

A function must have parameters. Pexp_function (params, _, body) must have non-empty params or a Pfunction_cases _ body.

*)
| Pexp_apply of expression * (Asttypes.arg_label * expression) list (*

Pexp_apply(E0, [(l1, E1) ; ... ; (ln, En)]) represents E0 ~l1:E1 ... ~ln:En

li can be Nolabel (non labeled argument), Labelled (labelled arguments) or Optional (optional argument).

Invariant: n > 0

*)
| Pexp_match of expression * case list (*

match E0 with P1 -> E1 | ... | Pn -> En

*)
| Pexp_try of expression * case list (*

try E0 with P1 -> E1 | ... | Pn -> En

*)
| Pexp_tuple of expression list (*

Expressions (E1, ..., En)

Invariant: n >= 2

*)
| Pexp_construct of Longident.t Asttypes.loc * expression option (*

Pexp_construct(C, exp) represents:

  • C when exp is None,
  • C E when exp is Some E,
  • C (E1, ..., En) when exp is Some (Pexp_tuple[E1;...;En])
*)
| Pexp_variant of Asttypes.label * expression option (*

Pexp_variant(`A, exp) represents

  • `A when exp is None
  • `A E when exp is Some E
*)
| Pexp_record of (Longident.t Asttypes.loc * expression) list
* expression option		 (*

Pexp_record([(l1,P1) ; ... ; (ln,Pn)], exp0) represents

  • { l1=P1; ...; ln=Pn } when exp0 is None
  • { E0 with l1=P1; ...; ln=Pn } when exp0 is Some E0

Invariant: n > 0

*)
| Pexp_field of expression * Longident.t Asttypes.loc (*

E.l

*)
| Pexp_setfield of expression * Longident.t Asttypes.loc * expression (*

E1.l <- E2

*)
| Pexp_array of expression list (*

[| E1; ...; En |]

*)
| Pexp_ifthenelse of expression * expression * expression option (*

if E1 then E2 else E3

*)
| Pexp_sequence of expression * expression (*

E1; E2

*)
| Pexp_while of expression * expression (*

while E1 do E2 done

*)
| Pexp_for of pattern * expression * expression
* Asttypes.direction_flag * expression		 (*

Pexp_for(i, E1, E2, direction, E3) represents:

  • for i = E1 to E2 do E3 done when direction is Upto
  • for i = E1 downto E2 do E3 done when direction is Downto
*)
| Pexp_constraint of expression * core_type (*

(E : T)

*)
| Pexp_coerce of expression * core_type option * core_type (*

Pexp_coerce(E, from, T) represents

  • (E :> T) when from is None,
  • (E : T0 :> T) when from is Some T0.
*)
| Pexp_send of expression * Asttypes.label Asttypes.loc (*

E # m

*)
| Pexp_new of Longident.t Asttypes.loc (*

new M.c

*)
| Pexp_setinstvar of Asttypes.label Asttypes.loc * expression (*

x <- 2

*)
| Pexp_override of (Asttypes.label Asttypes.loc * expression) list (*

{< x1 = E1; ...; xn = En >}

*)
| Pexp_letmodule of string option Asttypes.loc * module_expr * expression (*

let module M = ME in E

*)
| Pexp_letexception of extension_constructor * expression (*

let exception C in E

*)
| Pexp_assert of expression (*

assert E.

Note: assert false is treated in a special way by the type-checker.

*)
| Pexp_lazy of expression (*

lazy E

*)
| Pexp_poly of expression * core_type option (*

Used for method bodies.

Can only be used as the expression under Cfk_concrete for methods (not values).

*)
| Pexp_object of class_structure (*

object ... end

*)
| Pexp_newtype of string Asttypes.loc * expression (*

fun (type t) -> E

*)
| Pexp_pack of module_expr (*

(module ME).

(module ME : S) is represented as Pexp_constraint(Pexp_pack ME, Ptyp_package S)

*)
| Pexp_open of open_declaration * expression (*

- M.(E)

  • let open M in E
  • let open! M in E
*)
| Pexp_letop of letop (*

- let* P = E0 in E1

  • let* P0 = E00 and* P1 = E01 in E1
*)
| Pexp_extension of extension (*

[%id]

*)
| Pexp_unreachable (*

.

*) 
type case = {
   pc_lhs : pattern;
   pc_guard : expression option;
   pc_rhs : expression;
}

Values of type Parsetree.case represents (P -> E) or (P when E0 -> E)

type letop = {
   let_ : binding_op;
   ands : binding_op list;
   body : expression;
} 
type binding_op = {
   pbop_op : string Asttypes.loc;
   pbop_pat : pattern;
   pbop_exp : expression;
   pbop_loc : Location.t;
} 
type function_param_desc =
| Pparam_val of Asttypes.arg_label * expression option * pattern (*

Pparam_val (lbl, exp0, P) represents the parameter:

Note: If E0 is provided, only Optional is allowed.

*)
| Pparam_newtype of string Asttypes.loc (*

Pparam_newtype x represents the parameter (type x). x carries the location of the identifier, whereas the pparam_loc on the enclosing function_param node is the location of the (type x) as a whole.

Multiple parameters (type a b c) are represented as multiple Pparam_newtype nodes, let's say:

 [ { pparam_kind = Pparam_newtype a; pparam_loc = loc1 };
           { pparam_kind = Pparam_newtype b; pparam_loc = loc2 };
           { pparam_kind = Pparam_newtype c; pparam_loc = loc3 };
         ]

Here, the first loc loc1 is the location of (type a b c), and the subsequent locs loc2 and loc3 are the same as loc1, except marked as ghost locations. The locations on a, b, c, correspond to the variables a, b, and c in the source code.

*) 
type function_param = {
   pparam_loc : Location.t;
   pparam_desc : function_param_desc;
} 
type function_body =
| Pfunction_body of expression
| Pfunction_cases of case list * Location.t * attributes (*

In Pfunction_cases (_, loc, attrs), the location extends from the start of the function keyword to the end of the last case. The compiler will only use typechecking-related attributes from attrs, e.g. enabling or disabling a warning.

*)

See the comment on Pexp_function.

type type_constraint =
| Pconstraint of core_type
| Pcoerce of core_type option * core_type (*

See the comment on Pexp_function.

*)

Value descriptions

type value_description = {
   pval_name : string Asttypes.loc;
   pval_type : core_type;
   pval_prim : string list;
   pval_attributes : attributes; (*

... [@@id1] [@@id2]

*)
   pval_loc : Location.t;
}

Values of type Parsetree.value_description represents:

  • val x: T, when pval_prim is []
  • external x: T = "s1" ... "sn" when pval_prim is ["s1";..."sn"]

Type declarations

type type_declaration = {
   ptype_name : string Asttypes.loc;
   ptype_params : (core_type * (Asttypes.variance * Asttypes.injectivity)) list; (*

('a1,...'an) t

*)
   ptype_cstrs : (core_type * core_type * Location.t) list; (*

... constraint T1=T1'  ... constraint Tn=Tn'

*)
   ptype_kind : type_kind;
   ptype_private : Asttypes.private_flag; (*

for = private ...

*)
   ptype_manifest : core_type option; (*

represents = T

*)
   ptype_attributes : attributes; (*

... [@@id1] [@@id2]

*)
   ptype_loc : Location.t;
}

Here are type declarations and their representation, for various ptype_kind and ptype_manifest values:

  • type t when type_kind is Ptype_abstract, and manifest is None,
  • type t = T0 when type_kind is Ptype_abstract, and manifest is Some T0,
  • type t = C of T | ... when type_kind is Ptype_variant, and manifest is None,
  • type t = T0 = C of T | ... when type_kind is Ptype_variant, and manifest is Some T0,
  • type t = {l: T; ...} when type_kind is Ptype_record, and manifest is None,
  • type t = T0 = {l : T; ...} when type_kind is Ptype_record, and manifest is Some T0,
  • type t = .. when type_kind is Ptype_open, and manifest is None.
type type_kind =
| Ptype_abstract
| Ptype_variant of constructor_declaration list
| Ptype_record of label_declaration list (*

Invariant: non-empty list

*)
| Ptype_open 
type label_declaration = {
   pld_name : string Asttypes.loc;
   pld_mutable : Asttypes.mutable_flag;
   pld_type : core_type;
   pld_loc : Location.t;
   pld_attributes : attributes; (*

l : T [@id1] [@id2]

*)
}

- { ...; l: T; ... } when pld_mutable is Immutable,

Note: T can be a Ptyp_poly.

type constructor_declaration = {
   pcd_name : string Asttypes.loc;
   pcd_vars : string Asttypes.loc list;
   pcd_args : constructor_arguments;
   pcd_res : core_type option;
   pcd_loc : Location.t;
   pcd_attributes : attributes; (*

C of ... [@id1] [@id2]

*)
} 
type constructor_arguments =
| Pcstr_tuple of core_type list
| Pcstr_record of label_declaration list (*

Values of type Parsetree.constructor_declaration represents the constructor arguments of:

  • C of T1 * ... * Tn when res = None, and args = Pcstr_tuple [T1; ... ; Tn],
  • C: T0 when res = Some T0, and args = Pcstr_tuple [],
  • C: T1 * ... * Tn -> T0 when res = Some T0, and args = Pcstr_tuple [T1; ... ; Tn],
  • C of {...} when res = None, and args = Pcstr_record [...],
  • C: {...} -> T0 when res = Some T0, and args = Pcstr_record [...].
*) 
type type_extension = {
   ptyext_path : Longident.t Asttypes.loc;
   ptyext_params : (core_type * (Asttypes.variance * Asttypes.injectivity)) list;
   ptyext_constructors : extension_constructor list;
   ptyext_private : Asttypes.private_flag;
   ptyext_loc : Location.t;
   ptyext_attributes : attributes; (*

... @@id1 @@id2

*)
}

Definition of new extensions constructors for the extensive sum type t (type t += ...).

type extension_constructor = {
   pext_name : string Asttypes.loc;
   pext_kind : extension_constructor_kind;
   pext_loc : Location.t;
   pext_attributes : attributes; (*

C of ... [@id1] [@id2]

*)
} 
type type_exception = {
   ptyexn_constructor : extension_constructor;
   ptyexn_loc : Location.t;
   ptyexn_attributes : attributes; (*

... [@@id1] [@@id2]

*)
}

Definition of a new exception (exception E).

type extension_constructor_kind =
| Pext_decl of string Asttypes.loc list * constructor_arguments
* core_type option		 (*

Pext_decl(existentials, c_args, t_opt) describes a new extension constructor. It can be:

  • C of T1 * ... * Tn when:
    • existentials is [],
    • c_args is [T1; ...; Tn],
    • t_opt is None
  • C: T0 when
    • existentials is [],
    • c_args is [],
    • t_opt is Some T0.
  • C: T1 * ... * Tn -> T0 when
    • existentials is [],
    • c_args is [T1; ...; Tn],
    • t_opt is Some T0.
  • C: 'a... . T1 * ... * Tn -> T0 when
    • existentials is ['a;...],
    • c_args is [T1; ... ; Tn],
    • t_opt is Some T0.
*)
| Pext_rebind of Longident.t Asttypes.loc (*

Pext_rebind(D) re-export the constructor D with the new name C

*)

Class language

Type expressions for the class language

type class_type = {
   pcty_desc : class_type_desc;
   pcty_loc : Location.t;
   pcty_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type class_type_desc =
| Pcty_constr of Longident.t Asttypes.loc * core_type list (*

- c

  • ['a1, ..., 'an] c
*)
| Pcty_signature of class_signature (*

object ... end

*)
| Pcty_arrow of Asttypes.arg_label * core_type * class_type (*

Pcty_arrow(lbl, T, CT) represents:

*)
| Pcty_extension of extension (*

%id

*)
| Pcty_open of open_description * class_type (*

let open M in CT

*) 
type class_signature = {
   pcsig_self : core_type;
   pcsig_fields : class_type_field list;
}

Values of type class_signature represents:

type class_type_field = {
   pctf_desc : class_type_field_desc;
   pctf_loc : Location.t;
   pctf_attributes : attributes; (*

... [@@id1] [@@id2]

*)
} 
type class_type_field_desc =
| Pctf_inherit of class_type (*

inherit CT

*)
| Pctf_val of (Asttypes.label Asttypes.loc * Asttypes.mutable_flag *
Asttypes.virtual_flag * core_type)		 (*

val x: T

*)
| Pctf_method of (Asttypes.label Asttypes.loc * Asttypes.private_flag *
Asttypes.virtual_flag * core_type)		 (*

method x: T

Note: T can be a Ptyp_poly.

*)
| Pctf_constraint of (core_type * core_type) (*

constraint T1 = T2

*)
| Pctf_attribute of attribute (*

[@@@id]

*)
| Pctf_extension of extension (*

[%%id]

*) 
type 'a class_infos = {
   pci_virt : Asttypes.virtual_flag;
   pci_params : (core_type * (Asttypes.variance * Asttypes.injectivity)) list;
   pci_name : string Asttypes.loc;
   pci_expr : 'a;
   pci_loc : Location.t;
   pci_attributes : attributes; (*

... [@@id1] [@@id2]

*)
}

Values of type class_expr class_infos represents:

  • class c = ...
  • class ['a1,...,'an] c = ...
  • class virtual c = ...

They are also used for "class type" declaration.

type class_description = class_type class_infos 
type class_type_declaration = class_type class_infos

Value expressions for the class language

type class_expr = {
   pcl_desc : class_expr_desc;
   pcl_loc : Location.t;
   pcl_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type class_expr_desc =
| Pcl_constr of Longident.t Asttypes.loc * core_type list (*

c and ['a1, ..., 'an] c

*)
| Pcl_structure of class_structure (*

object ... end

*)
| Pcl_fun of Asttypes.arg_label * expression option * pattern
* class_expr		 (*

Pcl_fun(lbl, exp0, P, CE) represents:

  • fun P -> CE when lbl is Nolabel and exp0 is None,
  • fun ~l:P -> CE when lbl is Labelled l and exp0 is None,
  • fun ?l:P -> CE when lbl is Optional l and exp0 is None,
  • fun ?l:(P = E0) -> CE when lbl is Optional l and exp0 is Some E0.
*)
| Pcl_apply of class_expr * (Asttypes.arg_label * expression) list (*

Pcl_apply(CE, [(l1,E1) ; ... ; (ln,En)]) represents CE ~l1:E1 ... ~ln:En. li can be empty (non labeled argument) or start with ? (optional argument).

Invariant: n > 0

*)
| Pcl_let of Asttypes.rec_flag * value_binding list * class_expr (*

Pcl_let(rec, [(P1, E1); ... ; (Pn, En)], CE) represents:

  • let P1 = E1 and ... and Pn = EN in CE when rec is Nonrecursive,
  • let rec P1 = E1 and ... and Pn = EN in CE when rec is Recursive.
*)
| Pcl_constraint of class_expr * class_type (*

(CE : CT)

*)
| Pcl_extension of extension (*

[%id]

*)
| Pcl_open of open_description * class_expr (*

let open M in CE

*) 
type class_structure = {
   pcstr_self : pattern;
   pcstr_fields : class_field list;
}

Values of type Parsetree.class_structure represents:

type class_field = {
   pcf_desc : class_field_desc;
   pcf_loc : Location.t;
   pcf_attributes : attributes; (*

... [@@id1] [@@id2]

*)
} 
type class_field_desc =
| Pcf_inherit of Asttypes.override_flag * class_expr * string Asttypes.loc option (*

Pcf_inherit(flag, CE, s) represents:

  • inherit CE when flag is Fresh and s is None,
  • inherit CE as x when flag is Fresh and s is Some x,
  • inherit! CE when flag is Override and s is None,
  • inherit! CE as x when flag is Override and s is Some x
*)
| Pcf_val of (Asttypes.label Asttypes.loc * Asttypes.mutable_flag *
class_field_kind)		 (*

Pcf_val(x,flag, kind) represents:

*)
| Pcf_method of (Asttypes.label Asttypes.loc * Asttypes.private_flag *
class_field_kind)		 (*

- method x = E (E can be a Pexp_poly)

  • method virtual x: T (T can be a Ptyp_poly)
*)
| Pcf_constraint of (core_type * core_type) (*

constraint T1 = T2

*)
| Pcf_initializer of expression (*

initializer E

*)
| Pcf_attribute of attribute (*

[@@@id]

*)
| Pcf_extension of extension (*

[%%id]

*) 
type class_field_kind =
| Cfk_virtual of core_type
| Cfk_concrete of Asttypes.override_flag * expression 
type class_declaration = class_expr class_infos

Module language

Type expressions for the module language

type module_type = {
   pmty_desc : module_type_desc;
   pmty_loc : Location.t;
   pmty_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type module_type_desc =
| Pmty_ident of Longident.t Asttypes.loc (*

Pmty_ident(S) represents S

*)
| Pmty_signature of signature (*

sig ... end

*)
| Pmty_functor of functor_parameter * module_type (*

functor(X : MT1) -> MT2

*)
| Pmty_with of module_type * with_constraint list (*

MT with ...

*)
| Pmty_typeof of module_expr (*

module type of ME

*)
| Pmty_extension of extension (*

[%id]

*)
| Pmty_alias of Longident.t Asttypes.loc (*

(module M)

*) 
type functor_parameter =
| Unit (*

()

*)
| Named of string option Asttypes.loc * module_type (*

Named(name, MT) represents:

  • (X : MT) when name is Some X,
  • (_ : MT) when name is None
*) 
type signature = signature_item list 
type signature_item = {
   psig_desc : signature_item_desc;
   psig_loc : Location.t;
} 
type signature_item_desc =
| Psig_value of value_description (*

- val x: T

  • external x: T = "s1" ... "sn"
*)
| Psig_type of Asttypes.rec_flag * type_declaration list (*

type t1 = ... and ... and tn  = ...

*)
| Psig_typesubst of type_declaration list (*

type t1 := ... and ... and tn := ...

*)
| Psig_typext of type_extension (*

type t1 += ...

*)
| Psig_exception of type_exception (*

exception C of T

*)
| Psig_module of module_declaration (*

module X = M and module X : MT

*)
| Psig_modsubst of module_substitution (*

module X := M

*)
| Psig_recmodule of module_declaration list (*

module rec X1 : MT1 and ... and Xn : MTn

*)
| Psig_modtype of module_type_declaration (*

module type S = MT and module type S

*)
| Psig_modtypesubst of module_type_declaration (*

module type S :=  ...

*)
| Psig_open of open_description (*

open X

*)
| Psig_include of include_description (*

include MT

*)
| Psig_class of class_description list (*

class c1 : ... and ... and cn : ...

*)
| Psig_class_type of class_type_declaration list (*

class type ct1 = ... and ... and ctn = ...

*)
| Psig_attribute of attribute (*

[@@@id]

*)
| Psig_extension of extension * attributes (*

[%%id]

*) 
type module_declaration = {
   pmd_name : string option Asttypes.loc;
   pmd_type : module_type;
   pmd_attributes : attributes; (*

... [@@id1] [@@id2]

*)
   pmd_loc : Location.t;
}

Values of type module_declaration represents S : MT

type module_substitution = {
   pms_name : string Asttypes.loc;
   pms_manifest : Longident.t Asttypes.loc;
   pms_attributes : attributes; (*

... [@@id1] [@@id2]

*)
   pms_loc : Location.t;
}

Values of type module_substitution represents S := M

type module_type_declaration = {
   pmtd_name : string Asttypes.loc;
   pmtd_type : module_type option;
   pmtd_attributes : attributes; (*

... [@@id1] [@@id2]

*)
   pmtd_loc : Location.t;
}

Values of type module_type_declaration represents:

  • S = MT,
  • S for abstract module type declaration, when pmtd_type is None.
type 'a open_infos = {
   popen_expr : 'a;
   popen_override : Asttypes.override_flag;
   popen_loc : Location.t;
   popen_attributes : attributes;
}

Values of type 'a open_infos represents:

type open_description = Longident.t Asttypes.loc open_infos

Values of type open_description represents:

  • open M.N
  • open M(N).O
type open_declaration = module_expr open_infos

Values of type open_declaration represents:

  • open M.N
  • open M(N).O
  • open struct ... end
type 'a include_infos = {
   pincl_mod : 'a;
   pincl_loc : Location.t;
   pincl_attributes : attributes;
} 
type include_description = module_type include_infos

Values of type include_description represents include MT

type include_declaration = module_expr include_infos

Values of type include_declaration represents include ME

type with_constraint =
| Pwith_type of Longident.t Asttypes.loc * type_declaration (*

with type X.t = ...

Note: the last component of the longident must match the name of the type_declaration.

*)
| Pwith_module of Longident.t Asttypes.loc * Longident.t Asttypes.loc (*

with module X.Y = Z

*)
| Pwith_modtype of Longident.t Asttypes.loc * module_type (*

with module type X.Y = Z

*)
| Pwith_modtypesubst of Longident.t Asttypes.loc * module_type (*

with module type X.Y := sig end

*)
| Pwith_typesubst of Longident.t Asttypes.loc * type_declaration (*

with type X.t := ..., same format as [Pwith_type]

*)
| Pwith_modsubst of Longident.t Asttypes.loc * Longident.t Asttypes.loc (*

with module X.Y := Z

*)

Value expressions for the module language

type module_expr = {
   pmod_desc : module_expr_desc;
   pmod_loc : Location.t;
   pmod_attributes : attributes; (*

... [@id1] [@id2]

*)
} 
type module_expr_desc =
| Pmod_ident of Longident.t Asttypes.loc (*

X

*)
| Pmod_structure of structure (*

struct ... end

*)
| Pmod_functor of functor_parameter * module_expr (*

functor(X : MT1) -> ME

*)
| Pmod_apply of module_expr * module_expr (*

ME1(ME2)

*)
| Pmod_apply_unit of module_expr (*

ME1()

*)
| Pmod_constraint of module_expr * module_type (*

(ME : MT)

*)
| Pmod_unpack of expression (*

(val E)

*)
| Pmod_extension of extension (*

[%id]

*) 
type structure = structure_item list 
type structure_item = {
   pstr_desc : structure_item_desc;
   pstr_loc : Location.t;
} 
type structure_item_desc =
| Pstr_eval of expression * attributes (*

E

*)
| Pstr_value of Asttypes.rec_flag * value_binding list (*

Pstr_value(rec, [(P1, E1 ; ... ; (Pn, En))]) represents:

  • let P1 = E1 and ... and Pn = EN when rec is Nonrecursive,
  • let rec P1 = E1 and ... and Pn = EN  when rec is Recursive.
*)
| Pstr_primitive of value_description (*

- val x: T

  • external x: T = "s1" ... "sn" 
*)
| Pstr_type of Asttypes.rec_flag * type_declaration list (*

type t1 = ... and ... and tn = ...

*)
| Pstr_typext of type_extension (*

type t1 += ...

*)
| Pstr_exception of type_exception (*

- exception C of T

  • exception C = M.X
*)
| Pstr_module of module_binding (*

module X = ME

*)
| Pstr_recmodule of module_binding list (*

module rec X1 = ME1 and ... and Xn = MEn

*)
| Pstr_modtype of module_type_declaration (*

module type S = MT

*)
| Pstr_open of open_declaration (*

open X

*)
| Pstr_class of class_declaration list (*

class c1 = ... and ... and cn = ...

*)
| Pstr_class_type of class_type_declaration list (*

class type ct1 = ... and ... and ctn = ...

*)
| Pstr_include of include_declaration (*

include ME

*)
| Pstr_attribute of attribute (*

[@@@id]

*)
| Pstr_extension of extension * attributes (*

[%%id]

*) 
type value_constraint =
| Pvc_constraint of {
   locally_abstract_univars : string Asttypes.loc list;
   typ : core_type;
}
| Pvc_coercion of {
   ground : core_type option;
   coercion : core_type;
} 		(*

- Pvc_constraint { locally_abstract_univars=[]; typ} is a simple type constraint on a value binding:  let x : typ

  • More generally, in Pvc_constraint { locally_abstract_univars; typ} locally_abstract_univars is the list of locally abstract type variables in  let x: type a ... . typ 
  • Pvc_coercion { ground=None; coercion } represents let x :> typ
  • Pvc_coercion { ground=Some g; coercion } represents let x : g :> typ
*) 
type value_binding = {
   pvb_pat : pattern;
   pvb_expr : expression;
   pvb_constraint : value_constraint option;
   pvb_attributes : attributes;
   pvb_loc : Location.t;
}

let pat : type_constraint = exp

type module_binding = {
   pmb_name : string option Asttypes.loc;
   pmb_expr : module_expr;
   pmb_attributes : attributes;
   pmb_loc : Location.t;
}

Values of type module_binding represents module X = ME

Toplevel

Toplevel phrases

type toplevel_phrase =
| Ptop_def of structure
| Ptop_dir of toplevel_directive (*

#use, #load ...

*) 
type toplevel_directive = {
   pdir_name : string Asttypes.loc;
   pdir_arg : directive_argument option;
   pdir_loc : Location.t;
} 
type directive_argument = {
   pdira_desc : directive_argument_desc;
   pdira_loc : Location.t;
} 
type directive_argument_desc =
| Pdir_string of string
| Pdir_int of string * char option
| Pdir_ident of Longident.t
| Pdir_bool of bool