Module Util

This module contains numerous utility functions on strings, lists, arrays, etc.

Mapping under pairs

val on_fst : ('a -> 'b) -> ('a * 'c) -> 'b * 'c
val on_snd : ('a -> 'b) -> ('c * 'a) -> 'c * 'b
val map_pair : ('a -> 'b) -> ('a * 'a) -> 'b * 'b

Folding under pairs

val fold_fst : ('c -> 'a -> 'c * 'a) -> 'c -> ('a * 'b) -> 'c * ('a * 'b)
val fold_snd : ('c -> 'b -> 'c * 'b) -> 'c -> ('a * 'b) -> 'c * ('a * 'b)

Equality on pairs

val eq_pair : ('a -> 'a -> bool) -> ('b -> 'b -> bool) -> ('a * 'b) -> ('a * 'b) -> bool

Mapping under triplets

val on_pi1 : ('a -> 'b) -> ('a * 'c * 'd) -> 'b * 'c * 'd
val on_pi2 : ('a -> 'b) -> ('c * 'a * 'd) -> 'c * 'b * 'd
val on_pi3 : ('a -> 'b) -> ('c * 'd * 'a) -> 'c * 'd * 'b
Projections from triplets
val pi1 : ('a * 'b * 'c) -> 'a
val pi2 : ('a * 'b * 'c) -> 'b
val pi3 : ('a * 'b * 'c) -> 'c
Chars.
val is_letter : char -> bool
val is_digit : char -> bool
val is_ident_tail : char -> bool
val is_blank : char -> bool
Empty type
module Empty : sig ... end
Strings.
module String = CString
val subst_command_placeholder : string -> string -> string

Substitute %s in the first chain by the second chain

Lists.
module List : module type of CList
val (@) : 'a list -> 'a list -> 'a list
Arrays.
Sets.
module Set : module type of CSet
Maps.
module Map : module type of CMap
Matrices.
val matrix_transpose : 'a list list -> 'a list list
Functions.
val identity : 'a -> 'a
val (%>) : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c

Left-to-right function composition:

f1 %> f2 is fun x -> f2 (f1 x).

f1 %> f2 %> f3 is fun x -> f3 (f2 (f1 x)).

f1 %> f2 %> f3 %> f4 is fun x -> f4 (f3 (f2 (f1 x)))

etc.

val const : 'a -> 'b -> 'a
val iterate : ('a -> 'a) -> int -> 'a -> 'a
val repeat : int -> ('a -> unit) -> 'a -> unit
val app_opt : ('a -> 'a) option -> 'a -> 'a
Delayed computations.
type 'a delayed = unit -> 'a
val delayed_force : 'a delayed -> 'a
val try_finally : ('a -> 'b) -> 'a -> ('c -> unit) -> 'c -> 'b

try_finally f x g y applies the main code f to x and returns the result after having applied the finalization code g to y. If the main code raises the exception exn, the finalization code is executed and exn is raised. If the finalization code itself fails, the exception returned is always the one from the finalization code. Credit X.Leroy, D.Remy.

Enriched exceptions
type iexn = Exninfo.iexn
val iraise : Exninfo.iexn -> 'a
Misc.
type ('a, 'b) union = ('a, 'b) CSig.union =
| Inl of 'a
| Inr of 'b(*

Union type

*)
module Union : sig ... end
val map_union : ('a -> 'c) -> ('b -> 'd) -> ('a, 'b) union -> ('c, 'd) union

Alias for Union.map

type 'a until = 'a CSig.until =
| Stop of 'a
| Cont of 'a(*

Used for browsable-until structures.

*)
type ('a, 'b) eq = ('a, 'b) CSig.eq =
| Refl : ('a, 'a) eq
val sym : ('a, 'b) eq -> ('b, 'a) eq
module Compare : sig ... end

Helpers to write comparison functions

val open_utf8_file_in : string -> Stdlib.in_channel

Open an utf-8 encoded file and skip the byte-order mark if any.

val set_temporary_memory : unit -> ('a -> 'a) * (unit -> 'a)

A trick which can typically be used to store on the fly the computation of values in the "when" clause of a "match" then retrieve the evaluated result in the r.h.s of the clause