ast_iterator.mli

(***********************************************************************)
(*                                                                     *)
(*                                OCaml                                *)
(*                                                                     *)
(*                     Nicolas Ojeda Bar, LexiFi                       *)
(*                                                                     *)
(*  Copyright 2012 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(** {!iterator} allows to implement AST inspection using open recursion.  A
    typical mapper would be based on {!default_iterator}, a trivial iterator,
    and will fall back on it for handling the syntax it does not modify. *)

open Parsetree

(** {2 A generic Parsetree iterator} *)

type iterator = {
  attribute: iterator -> attribute -> unit;
  attributes: iterator -> attribute list -> unit;
  case: iterator -> case -> unit;
  cases: iterator -> case list -> unit;
  class_declaration: iterator -> class_declaration -> unit;
  class_description: iterator -> class_description -> unit;
  class_expr: iterator -> class_expr -> unit;
  class_field: iterator -> class_field -> unit;
  class_signature: iterator -> class_signature -> unit;
  class_structure: iterator -> class_structure -> unit;
  class_type: iterator -> class_type -> unit;
  class_type_declaration: iterator -> class_type_declaration -> unit;
  class_type_field: iterator -> class_type_field -> unit;
  constructor_declaration: iterator -> constructor_declaration -> unit;
  expr: iterator -> expression -> unit;
  extension: iterator -> extension -> unit;
  extension_constructor: iterator -> extension_constructor -> unit;
  include_declaration: iterator -> include_declaration -> unit;
  include_description: iterator -> include_description -> unit;
  label_declaration: iterator -> label_declaration -> unit;
  location: iterator -> Location.t -> unit;
  module_binding: iterator -> module_binding -> unit;
  module_declaration: iterator -> module_declaration -> unit;
  module_expr: iterator -> module_expr -> unit;
  module_type: iterator -> module_type -> unit;
  module_type_declaration: iterator -> module_type_declaration -> unit;
  open_description: iterator -> open_description -> unit;
  pat: iterator -> pattern -> unit;
  payload: iterator -> payload -> unit;
  signature: iterator -> signature -> unit;
  signature_item: iterator -> signature_item -> unit;
  structure: iterator -> structure -> unit;
  structure_item: iterator -> structure_item -> unit;
  typ: iterator -> core_type -> unit;
  type_declaration: iterator -> type_declaration -> unit;
  type_extension: iterator -> type_extension -> unit;
  type_kind: iterator -> type_kind -> unit;
  value_binding: iterator -> value_binding -> unit;
  value_description: iterator -> value_description -> unit;
  with_constraint: iterator -> with_constraint -> unit;
}
(** A [iterator] record implements one "method" per syntactic category,
    using an open recursion style: each method takes as its first
    argument the iterator to be applied to children in the syntax
    tree. *)

val default_iterator: iterator
(** A default iterator, which implements a "do not do anything" mapping. *)