# Module Location

    module Location: sig .. end

Source code locations (ranges of positions), used in parsetree.

    type t = Warnings.loc = {

`` | `loc_start : `Lexing.position`;`
`` | `loc_end : `Lexing.position`;`
`` | `loc_ghost : `bool`;`

}

Note on the use of Lexing.position in this module. If `pos_fname = ""`, then use `!input_name` instead. If `pos_lnum = -1`, then `pos_bol = 0`. Use `pos_cnum` and re-parse the file to get the line and character numbers. Else all fields are correct.

    val none : t

An arbitrary value of type `t`; describes an empty ghost range.

    val in_file : string -> t

Return an empty ghost range located in a given file.

    val init : Lexing.lexbuf -> string -> unit

Set the file name and line number of the `lexbuf` to be the start of the named file.

    val curr : Lexing.lexbuf -> t

Get the location of the current token from the `lexbuf`.

    val symbol_rloc : unit -> t

    val symbol_gloc : unit -> t

    val rhs_loc : int -> t

`rhs_loc n` returns the location of the symbol at position `n`, starting at 1, in the current parser rule.

    val input_name : string ref

    val input_lexbuf : Lexing.lexbuf option ref

    val get_pos_info : Lexing.position -> string * int * int

    val print_loc : Format.formatter -> t -> unit

    val print_error_prefix : Format.formatter -> unit

    val print_error : Format.formatter -> t -> unit

    val print_error_cur_file : Format.formatter -> unit -> unit

    val print_warning : t -> Format.formatter -> Warnings.t -> unit

    val formatter_for_warnings : Format.formatter ref

    val prerr_warning : t -> Warnings.t -> unit

    val echo_eof : unit -> unit

    val reset : unit -> unit

    val default_printer : Format.formatter -> t -> unit

    val printer : (Format.formatter -> t -> unit) ref

    val warning_printer : (t -> Format.formatter -> Warnings.t -> unit) ref

Hook for intercepting warnings.

    val default_warning_printer : t -> Format.formatter -> Warnings.t -> unit

Original warning printer for use in hooks.

    val highlight_locations : Format.formatter -> t list -> bool

    val show_code_at_location : Format.formatter -> Lexing.lexbuf -> t -> unit

    type 'a loc = {

`` | `txt : `'a`;`
`` | `loc : `t`;`

}

    val mknoloc : 'a -> 'a loc

    val mkloc : 'a -> t -> 'a loc

    val print : Format.formatter -> t -> unit

    val print_compact : Format.formatter -> t -> unit

    val print_filename : Format.formatter -> string -> unit

    val rewrite_absolute_path : string -> string

rewrite absolute path to honor the BUILD_PATH_PREFIX_MAP variable (https://reproducible-builds.org/specs/build-path-prefix-map/) if it is set.

    val absolute_path : string -> string

    val show_filename : string -> string

In -absname mode, return the absolute path for this filename. Otherwise, returns the filename unchanged.

    val absname : bool ref

Support for located errors

    type error = {

`` | `loc : `t`;`
`` | `msg : `string`;`
`` | `sub : `error list`;`
`` | `if_highlight : `string`;`

}

    exception Already_displayed_error

    exception Error of error

    val error : ?loc:t ->
           ?sub:error list -> ?if_highlight:string -> string -> error

    val errorf : ?loc:t ->
           ?sub:error list ->
           ?if_highlight:string ->
           ('a, Format.formatter, unit, error) format4 -> 'a

    val raise_errorf : ?loc:t ->
           ?sub:error list ->
           ?if_highlight:string ->
           ('a, Format.formatter, unit, 'b) format4 -> 'a

    val error_of_printer : t -> (Format.formatter -> 'a -> unit) -> 'a -> error

    val error_of_printer_file : (Format.formatter -> 'a -> unit) -> 'a -> error

    val error_of_exn : exn -> [ `Already_displayed | `Ok of error ] option

    val register_error_of_exn : (exn -> error option) -> unit

Each compiler module which defines a custom type of exception which can surface as a user-visible error should register a "printer" for this exception using `register_error_of_exn`. The result of the printer is an `error` value containing a location, a message, and optionally sub-messages (each of them being located as well).

    val report_error : Format.formatter -> error -> unit

    val error_reporter : (Format.formatter -> error -> unit) ref

Hook for intercepting error reports.

    val default_error_reporter : Format.formatter -> error -> unit

Original error reporter for use in hooks.

    val report_exception : Format.formatter -> exn -> unit

Reraise the exception if it is unknown.

    val deprecated : ?def:t -> ?use:t -> t -> string -> unit