# Module Misc

    module Misc: sig .. end

`protect_refs l f` temporarily sets `r` to `v` for each `R (r, v)` in `l` while executing `f`. The previous contents of the references is restored even if `f` raises an exception.

    val fatal_error : string -> 'a

    val fatal_errorf : ('a, Format.formatter, unit, 'b) format4 -> 'a

    exception Fatal_error

    val try_finally : (unit -> 'a) -> (unit -> unit) -> 'a

    val map_end : ('a -> 'b) -> 'a list -> 'b list -> 'b list

    val map_left_right : ('a -> 'b) -> 'a list -> 'b list

    val for_all2 : ('a -> 'b -> bool) -> 'a list -> 'b list -> bool

    val replicate_list : 'a -> int -> 'a list

    val list_remove : 'a -> 'a list -> 'a list

    val split_last : 'a list -> 'a list * 'a

    val may : ('a -> unit) -> 'a option -> unit

    val may_map : ('a -> 'b) -> 'a option -> 'b option

    type ref_and_value =

`|` | `R : `'a ref * 'a` -> `ref_and_value``

    val protect_refs : ref_and_value list -> (unit -> 'a) -> 'a

`protect_refs l f` temporarily sets `r` to `v` for each `R (r, v)` in `l` while executing `f`. The previous contents of the references is restored even if `f` raises an exception.

    module Stdlib: sig .. end

    val find_in_path : string list -> string -> string

    val find_in_path_rel : string list -> string -> string

    val find_in_path_uncap : string list -> string -> string

    val remove_file : string -> unit

    val expand_directory : string -> string -> string

    val create_hashtable : int -> ('a * 'b) list -> ('a, 'b) Hashtbl.t

    val copy_file : in_channel -> out_channel -> unit

    val copy_file_chunk : in_channel -> out_channel -> int -> unit

    val string_of_file : in_channel -> string

    val log2 : int -> int

    val align : int -> int -> int

    val no_overflow_add : int -> int -> bool

    val no_overflow_sub : int -> int -> bool

    val no_overflow_mul : int -> int -> bool

    val no_overflow_lsl : int -> int -> bool

    module Int_literal_converter: sig .. end

    val chop_extensions : string -> string

    val search_substring : string -> string -> int -> int

    val replace_substring : before:string -> after:string -> string -> string

    val rev_split_words : string -> string list

    val get_ref : 'a list ref -> 'a list

    val fst3 : 'a * 'b * 'c -> 'a

    val snd3 : 'a * 'b * 'c -> 'b

    val thd3 : 'a * 'b * 'c -> 'c

    val fst4 : 'a * 'b * 'c * 'd -> 'a

    val snd4 : 'a * 'b * 'c * 'd -> 'b

    val thd4 : 'a * 'b * 'c * 'd -> 'c

    val for4 : 'a * 'b * 'c * 'd -> 'd

    module LongString: sig .. end

    val edit_distance : string -> string -> int -> int option

`edit_distance a b cutoff` computes the edit distance between strings `a` and `b`. To help efficiency, it uses a cutoff: if the distance `d` is smaller than `cutoff`, it returns `Some d`, else `None`.

The distance algorithm currently used is Damerau-Levenshtein: it computes the number of insertion, deletion, substitution of letters, or swapping of adjacent letters to go from one word to the other. The particular algorithm may change in the future.

    val spellcheck : string list -> string -> string list

`spellcheck env name` takes a list of names `env` that exist in the current environment and an erroneous `name`, and returns a list of suggestions taken from `env`, that are close enough to `name` that it may be a typo for one of them.

    val did_you_mean : Format.formatter -> (unit -> string list) -> unit

`did_you_mean ppf get_choices` hints that the user may have meant one of the option returned by calling `get_choices`. It does nothing if the returned list is empty.

The `unit -> ...` thunking is meant to delay any potentially-slow computation (typically computing edit-distance with many things from the current environment) to when the hint message is to be printed. You should print an understandable error message before calling `did_you_mean`, so that users get a clear notification of the failure even if producing the hint is slow.

    val cut_at : string -> char -> string * string

`String.cut_at s c` returns a pair containing the sub-string before the first occurrence of `c` in `s`, and the sub-string after the first occurrence of `c` in `s`. `let (before, after) = String.cut_at s c in
before ^ String.make 1 c ^ after` is the identity if `s` contains `c`.

Raise `Not_found` if the character does not appear in the string
Since 4.01

    module StringSet: Set.S  with type elt = string

    module StringMap: Map.S  with type key = string

    module Color: sig .. end

    val normalise_eol : string -> string

`normalise_eol s` returns a fresh copy of `s` with any '\r' characters removed. Intended for pre-processing text which will subsequently be printed on a channel which performs EOL transformations (i.e. Windows)

    val delete_eol_spaces : string -> string

`delete_eol_spaces s` returns a fresh copy of `s` with any end of line spaces removed. Intended to normalize the output of the toplevel for tests.

## Hook machinery

    type hook_info = {

`` | `sourcefile : `string`;`

}

    exception HookExnWrapper of {

    error : exn;

    hook_name : string;

    hook_info : hook_info;

    }

An exception raised by a hook will be wrapped into a `HookExnWrapper` constructor by the hook machinery.

    val raise_direct_hook_exn : exn -> 'a

A hook can use `raise_unwrapped_hook_exn` to raise an exception that will not be wrapped into a `HookExnWrapper`.

    module type HookSig = sig .. end

    module MakeHooks: functor (M : sig
    type t

    end) -> HookSig  with type t = M.t