module BatGlobal:sig
..end
Mutable global variable.
Often in OCaml you want to have a global variable, which is mutable
and uninitialized when declared. You can use a 'a option ref
but
this is not very convenient. The Global module provides functions
to easily create and manipulate such variables.
type 'a
t
Abstract type of a global
exception Global_not_initialized of string
Raised when a global variable is accessed without first having been assigned a value. The parameter contains the name of the global.
val empty : string -> 'a t
Returns an new named empty global. The name of the global can be any string. It identifies the global and makes debugging easier. Using the same string twice will not return the same global twice, but will create two globals with the same name.
val name : 'a t -> string
Retrieve the name of a global.
val set : 'a t -> 'a -> unit
Set the global value contents.
val get_exn : 'a t -> 'a
Get the global value contents - raise Global_not_initialized if not defined.
val get : 'a t -> 'a option
Return None
if the global is undefined, else Some v
where v
is
the current global value contents.
val undef : 'a t -> unit
Reset the global value contents to undefined.
val isdef : 'a t -> bool
Return true
if the global value has been set.