Legend:
Library
Module
Module type
Parameter
Class
Class type
Library
Module
Module type
Parameter
Class
Class type
Uopt.t
is an unboxed option: an option
-like type that incurs no allocation, without requiring a reserved value in the underlying type.
The downsides compared to option
are that:
Uopt.t
cannot be nested, i.e. used as 'a Uopt.t Uopt.t
, because trying to create Uopt.some Uopt.none
is not supported and would raise.float Uopt.t array
, or any type which has the same memory representation, since the representation of the array would vary depending on whether none
or some
is used to create the array. Using float Uopt.t Uniform_array.t
is fine.As a result, we advise against using this in systems that are not high performance.
When using Uopt, we recommend:
Uopt.t
(whether the type is abstract or not) to other APIs, so they are free to use Uopt internally (and also for memory safety in the cause of float Uopt.t
).Uopt.t
from your libraries when the type is abstract, so callers are free to use Uopt.t
on abstract types. Returning explicit Uopt.t
can be fine, although turning a type that's not Uopt into a type that is could break code.Since 'a Uopt.t
is abstract, manipulation of an 'a Uopt.t array
does runtime checks to see if this is a float array. This can be mostly avoided with Uniform_array.t
, although array creation will still do such checks, and you may want to use the set_with_caml_modify
kind of function to skip the immediacy checks.
include Base.Invariant.S1 with type 'a t := 'a t
val invariant : 'a Base__Invariant_intf.inv -> 'a t Base__Invariant_intf.inv
val none : _ t
val some : 'a -> 'a t
val is_none : _ t -> Base.bool
val is_some : _ t -> Base.bool
val value_exn : 'a t -> 'a
val value : 'a t -> default:'a -> 'a
val some_if : Base.bool -> 'a -> 'a t
val unsafe_value : 'a t -> 'a
It is safe to call unsafe_value t
iff is_some t
.
val to_option : 'a t -> 'a Base.option
val of_option : 'a Base.option -> 'a t
module Optional_syntax : sig ... end
module Local : sig ... end
Same as their global equivalents.