ocaml/typing/ctype.mli

75 lines
3.4 KiB
OCaml

(***********************************************************************)
(* *)
(* Caml Special Light *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1995 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Operations on core types *)
open Typedtree
val begin_def: unit -> unit
(* Raise the variable level by one at the beginning of a definition. *)
val end_def: unit -> unit
(* Lower the variable level by one at the end of a definition *)
val newvar: unit -> type_expr
(* Return a fresh variable *)
val new_global_var: unit -> type_expr
(* Return a fresh variable, bound at toplevel
(as type variables ['a] in type constraints). *)
val repr: type_expr -> type_expr
(* Return the canonical representative of a type. *)
val generalize: type_expr -> unit
(* Generalize in-place the given type *)
val make_nongen: type_expr -> unit
(* Make non-generalizable the given type *)
val instance: type_expr -> type_expr
(* Take an instance of a type scheme *)
val instance_constructor:
constructor_description -> type_expr list * type_expr
(* Same, for a constructor *)
val instance_label: label_description -> type_expr * type_expr
(* Same, for a label *)
val unify: Env.t -> type_expr -> type_expr -> unit
(* Unify the two types given. Raise [Unify] if not possible. *)
val filter_arrow: Env.t -> type_expr -> type_expr * type_expr
(* A special case of unification (with 'a -> 'b). *)
val moregeneral: Env.t -> type_expr -> type_expr -> bool
(* Check if the first type scheme is more general than the second. *)
val equal: Env.t -> type_expr list -> type_expr ->
type_expr list -> type_expr -> bool
(* [equal env [x1...xn] tau [y1...yn] sigma]
checks whether the parameterized types
[/\x1.../\xn.tau] and [/\y1.../\yn.sigma] are equivalent. *)
val closed_schema: type_expr -> bool
(* Check whether the given type scheme contains no non-generic
type variables *)
val nondep_type: Env.t -> Ident.t -> type_expr -> type_expr
(* Return a type equivalent to the given type but without
references to the given module identifier. Raise [Not_found]
if no such type exists. *)
val free_type_ident: Env.t -> Ident.t list -> type_expr -> bool
(* Test whether one of the given type identifiers occur free
in the given type expression. *)
val is_generic: type_expr -> bool
(* Test whether the given type variable is generic *)
val arity: type_expr -> int
(* Return the arity (as for curried functions) of the given type. *)
val none: type_expr
(* A dummy type expression *)
val substitute:
type_expr list -> type_expr list -> type_expr -> type_expr
(* [substitute [v1...vN] [t1...tN] t]
returns a copy of [t] where the [vi] are replaced
by the [ti]. *)
exception Unify