Module Ctype

module Unification_trace : sig ... end

Unification traces are used to explain unification errors when printing error messages

exception Unify of Unification_trace.t
exception Tags of Asttypes.label * Asttypes.label
exception Cannot_expand
exception Cannot_apply
val init_def : int -> unit
val begin_def : unit -> unit
val end_def : unit -> unit
val begin_class_def : unit -> unit
val raise_nongen_level : unit -> unit
val reset_global_level : unit -> unit
val increase_global_level : unit -> int
val restore_global_level : int -> unit
type levels = {
current_level : int;
nongen_level : int;
global_level : int;
saved_level : (int * int) list;
}
val save_levels : unit -> levels
val set_levels : levels -> unit
val create_scope : unit -> int
val newvar : ?name:string -> unit -> Types.type_expr
val newvar2 : ?name:string -> int -> Types.type_expr
val new_global_var : ?name:string -> unit -> Types.type_expr
val newconstr : Path.t -> Types.type_expr list -> Types.type_expr
val none : Types.type_expr
val object_fields : Types.type_expr -> Types.type_expr
val flatten_fields : Types.type_expr -> (string * Types.field_kind * Types.type_expr) list * Types.type_expr

Transform a field type into a list of pairs label-type. The fields are sorted.

Beware of the interaction with GADTs:

Due to the introduction of object indexes for GADTs, the row variable of an object may now be an expansible type abbreviation. A first consequence is that flatten_fields will not completely flatten the object, since the type abbreviation will not be expanded (flatten_fields does not receive the current environment). Another consequence is that various functions may be called with the expansion of this type abbreviation, which is a Tfield, e.g. during printing.

Concrete problems have been fixed, but new bugs may appear in the future. (Test cases were added to typing-gadts/test.ml)

val associate_fields : (string * Types.field_kind * Types.type_expr) list -> (string * Types.field_kind * Types.type_expr) list -> (string * Types.field_kind * Types.type_expr * Types.field_kind * Types.type_expr) list * (string * Types.field_kind * Types.type_expr) list * (string * Types.field_kind * Types.type_expr) list
val opened_object : Types.type_expr -> bool
val close_object : Types.type_expr -> bool
val row_variable : Types.type_expr -> Types.type_expr
val set_object_name : Ident.t -> Types.type_expr -> Types.type_expr list -> Types.type_expr -> unit
val remove_object_name : Types.type_expr -> unit
val hide_private_methods : Types.type_expr -> unit
val find_cltype_for_path : Env.t -> Path.t -> Types.type_declaration * Types.type_expr
val sort_row_fields : (Asttypes.label * Types.row_field) list -> (Asttypes.label * Types.row_field) list
val filter_row_fields : bool -> (Asttypes.label * Types.row_field) list -> (Asttypes.label * Types.row_field) list
val generalize : Types.type_expr -> unit
val lower_contravariant : Env.t -> Types.type_expr -> unit
val generalize_structure : Types.type_expr -> unit
val generalize_spine : Types.type_expr -> unit
val correct_levels : Types.type_expr -> Types.type_expr
val limited_generalize : Types.type_expr -> Types.type_expr -> unit
val fully_generic : Types.type_expr -> bool
val check_scope_escape : Env.t -> int -> Types.type_expr -> unit
val instance : ?partial:bool -> Types.type_expr -> Types.type_expr
val generic_instance : Types.type_expr -> Types.type_expr
val instance_list : Types.type_expr list -> Types.type_expr list
val existential_name : Types.constructor_description -> Types.type_expr -> string
val instance_constructor : ?in_pattern:(Env.t ref * int) -> Types.constructor_description -> Types.type_expr list * Types.type_expr
val instance_parameterized_type : ?keep_names:bool -> Types.type_expr list -> Types.type_expr -> Types.type_expr list * Types.type_expr
val instance_parameterized_type_2 : Types.type_expr list -> Types.type_expr list -> Types.type_expr -> Types.type_expr list * Types.type_expr list * Types.type_expr
val instance_declaration : Types.type_declaration -> Types.type_declaration
val generic_instance_declaration : Types.type_declaration -> Types.type_declaration
val instance_class : Types.type_expr list -> Types.class_type -> Types.type_expr list * Types.class_type
val instance_poly : ?keep_names:bool -> bool -> Types.type_expr list -> Types.type_expr -> Types.type_expr list * Types.type_expr
val polyfy : Env.t -> Types.type_expr -> Types.type_expr list -> Types.type_expr * bool
val expand_head_once : Env.t -> Types.type_expr -> Types.type_expr
val expand_head : Env.t -> Types.type_expr -> Types.type_expr
val try_expand_once_opt : Env.t -> Types.type_expr -> Types.type_expr
val expand_head_opt : Env.t -> Types.type_expr -> Types.type_expr

The compiler's own version of expand_head necessary for type-based optimisations.

val full_expand : Env.t -> Types.type_expr -> Types.type_expr
val extract_concrete_typedecl : Env.t -> Types.type_expr -> Path.t * Path.t * Types.type_declaration
val enforce_constraints : Env.t -> Types.type_expr -> unit
val unify : Env.t -> Types.type_expr -> Types.type_expr -> unit
val unify_gadt : equations_level:int -> allow_recursive:bool -> Env.t ref -> Types.type_expr -> Types.type_expr -> unit TypePairs.t
val unify_var : Env.t -> Types.type_expr -> Types.type_expr -> unit
val filter_method : Env.t -> string -> Asttypes.private_flag -> Types.type_expr -> Types.type_expr
val check_filter_method : Env.t -> string -> Asttypes.private_flag -> Types.type_expr -> unit
val occur_in : Env.t -> Types.type_expr -> Types.type_expr -> bool
val deep_occur : Types.type_expr -> Types.type_expr -> bool
val moregeneral : Env.t -> bool -> Types.type_expr -> Types.type_expr -> bool
val rigidify : Types.type_expr -> Types.type_expr list
val all_distinct_vars : Env.t -> Types.type_expr list -> bool
val matches : Env.t -> Types.type_expr -> Types.type_expr -> bool
val reify_univars : Env.t -> Types.type_expr -> Types.type_expr
type class_match_failure =
| CM_Virtual_class
| CM_Parameter_arity_mismatch of int * int
| CM_Type_parameter_mismatch of Env.t * Unification_trace.t
| CM_Class_type_mismatch of Env.t * Types.class_type * Types.class_type
| CM_Parameter_mismatch of Env.t * Unification_trace.t
| CM_Val_type_mismatch of string * Env.t * Unification_trace.t
| CM_Meth_type_mismatch of string * Env.t * Unification_trace.t
| CM_Non_mutable_value of string
| CM_Non_concrete_value of string
| CM_Missing_value of string
| CM_Missing_method of string
| CM_Hide_public of string
| CM_Hide_virtual of string * string
| CM_Public_method of string
| CM_Private_method of string
| CM_Virtual_method of string
val match_class_types : ?trace:bool -> Env.t -> Types.class_type -> Types.class_type -> class_match_failure list
val equal : Env.t -> bool -> Types.type_expr list -> Types.type_expr list -> bool
val match_class_declarations : Env.t -> Types.type_expr list -> Types.class_type -> Types.type_expr list -> Types.class_type -> class_match_failure list
val enlarge_type : Env.t -> Types.type_expr -> Types.type_expr * bool
val subtype : Env.t -> Types.type_expr -> Types.type_expr -> unit -> unit
exception Nondep_cannot_erase of Ident.t
val nondep_type : Env.t -> Ident.t list -> Types.type_expr -> Types.type_expr
val nondep_type_decl : Env.t -> Ident.t list -> bool -> Types.type_declaration -> Types.type_declaration
val nondep_extension_constructor : Env.t -> Ident.t list -> Types.extension_constructor -> Types.extension_constructor
val nondep_class_declaration : Env.t -> Ident.t list -> Types.class_declaration -> Types.class_declaration
val nondep_cltype_declaration : Env.t -> Ident.t list -> Types.class_type_declaration -> Types.class_type_declaration
val cyclic_abbrev : Env.t -> Ident.t -> Types.type_expr -> bool
val is_contractive : Env.t -> Path.t -> bool
val normalize_type : Types.type_expr -> unit
val closed_schema : Env.t -> Types.type_expr -> bool
val free_variables : ?env:Env.t -> Types.type_expr -> Types.type_expr list
val closed_type_decl : Types.type_declaration -> Types.type_expr option
val closed_extension_constructor : Types.extension_constructor -> Types.type_expr option
type closed_class_failure =
| CC_Method of Types.type_expr * bool * string * Types.type_expr
| CC_Value of Types.type_expr * bool * string * Types.type_expr
val closed_class : Types.type_expr list -> Types.class_signature -> closed_class_failure option
val signature_of_class_type : Types.class_type -> Types.class_signature
val class_type_arity : Types.class_type -> int
val arity : Types.type_expr -> int
val collapse_conj_params : Env.t -> Types.type_expr list -> unit
val get_current_level : unit -> int
val wrap_trace_gadt_instances : Env.t -> ('a -> 'b) -> 'a -> 'b
val reset_reified_var_counter : unit -> unit
val immediacy : Env.t -> Types.type_expr -> Type_immediacy.t
val maybe_pointer_type : Env.t -> Types.type_expr -> bool
val package_subtype : (Env.t -> Path.t -> Longident.t list -> Types.type_expr list -> Path.t -> Longident.t list -> Types.type_expr list -> bool) ref
val mcomp : Env.t -> Types.type_expr -> Types.type_expr -> unit