ocaml-migrate-parsetree 1.8.0

Abstracting an OCaml frontend

module type Ast = sig ... end

Abstract view of a version of an OCaml Ast

type 'a _types = 'a
  constraint
    'a =
    < structure : _
    ; signature : _
    ; toplevel_phrase : _
    ; core_type : _
    ; expression : _
    ; pattern : _
    ; case : _
    ; type_declaration : _
    ; type_extension : _
    ; extension_constructor : _
    ; out_value : _
    ; out_type : _
    ; out_class_type : _
    ; out_module_type : _
    ; out_sig_item : _
    ; out_type_extension : _
    ; out_phrase : _
    ; mapper : _ >

type 'a get_structure = 'x constraint 'a _types = < structure : 'x.. >

type 'a get_signature = 'x constraint 'a _types = < signature : 'x.. >

type 'a get_toplevel_phrase = 'x constraint 'a _types = < toplevel_phrase : 'x.. >

type 'a get_core_type = 'x constraint 'a _types = < core_type : 'x.. >

type 'a get_expression = 'x constraint 'a _types = < expression : 'x.. >

type 'a get_pattern = 'x constraint 'a _types = < pattern : 'x.. >

type 'a get_case = 'x constraint 'a _types = < case : 'x.. >

type 'a get_type_declaration = 'x constraint 'a _types = < type_declaration : 'x.. >

type 'a get_type_extension = 'x constraint 'a _types = < type_extension : 'x.. >

type 'a get_extension_constructor = 'x constraint 'a _types = < extension_constructor : 'x.. >

type 'a get_out_value = 'x constraint 'a _types = < out_value : 'x.. >

type 'a get_out_type = 'x constraint 'a _types = < out_type : 'x.. >

type 'a get_out_class_type = 'x constraint 'a _types = < out_class_type : 'x.. >

type 'a get_out_module_type = 'x constraint 'a _types = < out_module_type : 'x.. >

type 'a get_out_sig_item = 'x constraint 'a _types = < out_sig_item : 'x.. >

type 'a get_out_type_extension = 'x constraint 'a _types = < out_type_extension : 'x.. >

type 'a get_out_phrase = 'x constraint 'a _types = < out_phrase : 'x.. >

type 'a get_mapper = 'x constraint 'a _types = < mapper : 'x.. >

type _ witnesses = private ..

A version of the OCaml frontend packs the ast with type witnesses so that equalities can be recovered dynamically.

type _ migration_info

migration_info is an opaque type that is used to generate migration functions.

module type OCaml_version = sig ... end

An OCaml frontend versions an Ast, version number and some witnesses for conversion.

type 'types ocaml_version =
  (module OCaml_version
  with type Ast.Ast_mapper.mapper = 'types get_mapper
   and type Ast.Outcometree.out_class_type = 'types get_out_class_type
   and type Ast.Outcometree.out_module_type = 'types get_out_module_type
   and type Ast.Outcometree.out_phrase = 'types get_out_phrase
   and type Ast.Outcometree.out_sig_item = 'types get_out_sig_item
   and type Ast.Outcometree.out_type = 'types get_out_type
   and type Ast.Outcometree.out_type_extension = 'types get_out_type_extension
   and type Ast.Outcometree.out_value = 'types get_out_value
   and type Ast.Parsetree.case = 'types get_case
   and type Ast.Parsetree.core_type = 'types get_core_type
   and type Ast.Parsetree.expression = 'types get_expression
   and type Ast.Parsetree.extension_constructor =
    'types get_extension_constructor
   and type Ast.Parsetree.pattern = 'types get_pattern
   and type Ast.Parsetree.signature = 'types get_signature
   and type Ast.Parsetree.structure = 'types get_structure
   and type Ast.Parsetree.toplevel_phrase = 'types get_toplevel_phrase
   and type Ast.Parsetree.type_declaration = 'types get_type_declaration
   and type Ast.Parsetree.type_extension = 'types get_type_extension)

Representing an ocaml version in type language

Concrete frontend instances

module OCaml_402 : OCaml_version with module Ast = Ast_402

val ocaml_402 : OCaml_402.types ocaml_version

module OCaml_403 : OCaml_version with module Ast = Ast_403

val ocaml_403 : OCaml_403.types ocaml_version

module OCaml_404 : OCaml_version with module Ast = Ast_404

val ocaml_404 : OCaml_404.types ocaml_version

module OCaml_405 : OCaml_version with module Ast = Ast_405

val ocaml_405 : OCaml_405.types ocaml_version

module OCaml_406 : OCaml_version with module Ast = Ast_406

val ocaml_406 : OCaml_406.types ocaml_version

module OCaml_407 : OCaml_version with module Ast = Ast_407

val ocaml_407 : OCaml_407.types ocaml_version

module OCaml_408 : OCaml_version with module Ast = Ast_408

val ocaml_408 : OCaml_408.types ocaml_version

module OCaml_409 : OCaml_version with module Ast = Ast_409

val ocaml_409 : OCaml_409.types ocaml_version

module OCaml_410 : OCaml_version with module Ast = Ast_410

val ocaml_410 : OCaml_410.types ocaml_version

module OCaml_411 : OCaml_version with module Ast = Ast_411

val ocaml_411 : OCaml_411.types ocaml_version

module OCaml_412 : OCaml_version with module Ast = Ast_412

val ocaml_412 : OCaml_412.types ocaml_version

module OCaml_current = OCaml_411

val ocaml_current : OCaml_current.types ocaml_version

val all_versions : (module OCaml_version) list

Migrating between different versions

type ('a, 'b) type_comparison =

| Lt : ('a, 'b) type_comparison
| Eq : ('a, 'a) type_comparison
| Gt : ('a, 'b) type_comparison

val compare_ocaml_version : 
  'a ocaml_version ->
  'b ocaml_version ->
  ('a, 'b) type_comparison

type ('from, 'to_) migration_functions = {

copy_structure : 'from get_structure -> 'to_ get_structure;
copy_signature : 'from get_signature -> 'to_ get_signature;
copy_toplevel_phrase : 'from get_toplevel_phrase -> 'to_ get_toplevel_phrase;
copy_core_type : 'from get_core_type -> 'to_ get_core_type;
copy_expression : 'from get_expression -> 'to_ get_expression;
copy_pattern : 'from get_pattern -> 'to_ get_pattern;
copy_case : 'from get_case -> 'to_ get_case;
copy_type_declaration : 'from get_type_declaration -> 'to_ get_type_declaration;
copy_type_extension : 'from get_type_extension -> 'to_ get_type_extension;
copy_extension_constructor : 'from get_extension_constructor -> 'to_ get_extension_constructor;
copy_out_value : 'from get_out_value -> 'to_ get_out_value;
copy_out_type : 'from get_out_type -> 'to_ get_out_type;
copy_out_class_type : 'from get_out_class_type -> 'to_ get_out_class_type;
copy_out_module_type : 'from get_out_module_type -> 'to_ get_out_module_type;
copy_out_sig_item : 'from get_out_sig_item -> 'to_ get_out_sig_item;
copy_out_type_extension : 'from get_out_type_extension -> 'to_ get_out_type_extension;
copy_out_phrase : 'from get_out_phrase -> 'to_ get_out_phrase;
copy_mapper : 'from get_mapper -> 'to_ get_mapper;

}

A record for migrating each AST construct between two known versions

val migration_identity : ('a, 'a) migration_functions

Migrating to the same version is no-op

val migration_compose : 
  ('a, 'b) migration_functions ->
  ('b, 'c) migration_functions ->
  ('a, 'c) migration_functions

Migrations can be composed

Represent the next or previous version of an Ast

type 'from immediate_migration =

| No_migration : 'from immediate_migration
(*
Cannot migrate earliest or latest supported version
*)
| Immediate_migration : ('from, 'to_) migration_functions * 'to_ ocaml_version -> 'from immediate_migration
(*
Pack the migration functions and the new version
*)

val immediate_migration : 
  'types ocaml_version ->
  [< `Next | `Previous ] ->
  'types immediate_migration

val migrate : 
  'from ocaml_version ->
  'to_ ocaml_version ->
  ('from, 'to_) migration_functions

Convenience definitions

module Convert (A : OCaml_version) (B : OCaml_version) : sig ... end

Module level migration

package ocaml-migrate-parsetree

Abstracting an OCaml frontend

Concrete frontend instances

Migrating between different versions

Convenience definitions