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|
(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Florian Angeletti, projet Cambium, Inria Paris *)
(* Antal Spector-Zabusky, Jane Street, New York *)
(* *)
(* Copyright 2018 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* Copyright 2021 Jane Street Group LLC *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
open Types
type position = First | Second
val swap_position : position -> position
val print_pos : position Format_doc.printer
type expanded_type = { ty: type_expr; expanded: type_expr }
(** [trivial_expansion ty] creates an [expanded_type] whose expansion is also
[ty]. Usually, you want [Ctype.expand_type] instead, since the expansion
carries useful information; however, in certain circumstances, the error is
about the expansion of the type, meaning that actually performing the
expansion produces more confusing or inaccurate output. *)
val trivial_expansion : type_expr -> expanded_type
type 'a diff = { got: 'a; expected: 'a }
(** [map_diff f {expected;got}] is [{expected=f expected; got=f got}] *)
val map_diff: ('a -> 'b) -> 'a diff -> 'b diff
(** Scope escape related errors *)
type 'a escape_kind =
| Constructor of Path.t
| Univ of type_expr
(* The type_expr argument of [Univ] is always a [Tunivar _],
we keep a [type_expr] to track renaming in {!Printtyp} *)
| Self
| Module_type of Path.t
| Equation of 'a
| Constraint
type 'a escape =
{ kind : 'a escape_kind;
context : type_expr option }
val map_escape : ('a -> 'b) -> 'a escape -> 'b escape
val explain: 'a list ->
(prev:'a option -> 'a -> 'b option) ->
'b option
(** Type indices *)
type unification = private Unification
type comparison = private Comparison
type fixed_row_case =
| Cannot_be_closed
| Cannot_add_tags of string list
type 'variety variant =
(* Common *)
| Incompatible_types_for : string -> _ variant
| No_tags : position * (Asttypes.label * row_field) list -> _ variant
(* Unification *)
| No_intersection : unification variant
| Fixed_row :
position * fixed_row_case * fixed_explanation -> unification variant
(* Equality & Moregen *)
| Presence_not_guaranteed_for : position * string -> comparison variant
| Openness : position (* Always [Second] for Moregen *) -> comparison variant
type 'variety obj =
(* Common *)
| Missing_field : position * string -> _ obj
| Abstract_row : position -> _ obj
(* Unification *)
| Self_cannot_be_closed : unification obj
type first_class_module =
| Package_cannot_scrape of Path.t
| Package_inclusion of Format_doc.doc
| Package_coercion of Format_doc.doc
type ('a, 'variety) elt =
(* Common *)
| Diff : 'a diff -> ('a, _) elt
| Variant : 'variety variant -> ('a, 'variety) elt
| Obj : 'variety obj -> ('a, 'variety) elt
| Escape : 'a escape -> ('a, _) elt
| Function_label_mismatch of Asttypes.arg_label diff
| Tuple_label_mismatch of string option diff
| Incompatible_fields : { name:string; diff: type_expr diff } -> ('a, _) elt
| First_class_module: first_class_module -> ('a,_) elt
(* Unification & Moregen; included in Equality for simplicity *)
| Rec_occur : type_expr * type_expr -> ('a, _) elt
type ('a, 'variety) t = ('a, 'variety) elt list
type 'variety trace = (type_expr, 'variety) t
type 'variety error = (expanded_type, 'variety) t
val map : ('a -> 'b) -> ('a, 'variety) t -> ('b, 'variety) t
val incompatible_fields :
name:string -> got:type_expr -> expected:type_expr -> (type_expr, _) elt
val swap_trace : ('a, 'variety) t -> ('a, 'variety) t
(** The traces (['variety t]) are the core error types. However, we bundle them
up into three "top-level" error types, which are used elsewhere:
[unification_error], [equality_error], and [moregen_error]. In the case of
[equality_error], this has to bundle in extra information; in general, it
distinguishes the three types of errors and allows us to distinguish traces
that are being built (or processed) from those that are complete and have
become the final error. These error types have the invariants that their
traces are nonempty; we ensure that through three smart constructors with
matching names. *)
type unification_error = private { trace : unification error } [@@unboxed]
type equality_error = private
{ trace : comparison error;
subst : (type_expr * type_expr) list }
type moregen_error = private { trace : comparison error } [@@unboxed]
val unification_error : trace:unification error -> unification_error
val equality_error :
trace:comparison error -> subst:(type_expr * type_expr) list -> equality_error
val moregen_error : trace:comparison error -> moregen_error
(** Wraps up the two different kinds of [comparison] errors in one type *)
type comparison_error =
| Equality_error of equality_error
| Moregen_error of moregen_error
(** Lift [swap_trace] to [unification_error] *)
val swap_unification_error : unification_error -> unification_error
module Subtype : sig
type 'a elt =
| Diff of 'a diff
type 'a t = 'a elt list
(** Just as outside [Subtype], we split traces, completed traces, and complete
errors. However, in a minor asymmetry, the name [Subtype.error_trace]
corresponds to the outside [error] type, and [Subtype.error] corresponds
to the outside [*_error] types (e.g., [unification_error]). This [error]
type has the invariant that the subtype trace is nonempty; note that no
such invariant is imposed on the unification trace. *)
type trace = type_expr t
type error_trace = expanded_type t
type unification_error_trace = unification error (** To avoid shadowing *)
type nonrec error = private
{ trace : error_trace
; unification_trace : unification error }
val error :
trace:error_trace -> unification_trace:unification_error_trace -> error
val map : ('a -> 'b) -> 'a t -> 'b t
end
|
