Module Util

module Util: sig .. end

Miscellaneous utility types and values.

exception Bug

Indicates a bug in the library. This exception is raised in cases that violate library or language invariants.

val id : 'a -> 'a

The identity function

val const : 'a -> 'b -> 'a

The K combinator

val (%) : ('a -> 'b) -> ('c -> 'a) -> 'c -> 'b

Function composition

val flip : ('a -> 'b -> 'c) -> 'b -> 'a -> 'c

Flip the arguments of a function

type ('a, 'b) either =

`\|`	`Left of 'a`
`\|`	`Right of 'b`

Anonymous sum types

val either : ('a, 'b) either -> ('a -> 'c) -> ('b -> 'c) -> 'c

Projection from the anonymous sum type Util.either

val maybe : 'a option -> (unit -> 'b) -> ('a -> 'b) -> 'b

Projection from option

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

Application inside option

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

Map exceptions to None

val unwind_protect : (unit -> 'a) -> (unit -> 'b) -> 'a

Call a thunk and then run cleanup code.

Util.unwind_protect thunk

    after

calls thunk. If thunk returns a value, it calls after and then returns the value. If thunk raises, it calls after and then re-raises.

val while_none : (unit -> 'a option) -> (unit -> 'b) -> 'a

Loop until a thunk returns Some v. Util.while_none cond body calls cond. If cond returns Some v then it returns v; if cond returns None, it calls body and then tries iterates.

val find' : ('a -> bool) -> 'a list -> 'a option

Find an element in a list. Like List.find', but returns an option rather than raising.

type protector = {

protector : 'a. (unit -> 'a) -> 'a;

}

Record type for universally quantified around advice.