module Option:sig..end
Functions for the option type.
Options are an Ocaml standard type that can be either None (undefined)
or Some x where x can be any value. Options are widely used in Ocaml
to represent undefined values (a little like NULL in C, but in a type
and memory safe way). This module adds some functions for working with
options.
val may : ('a -> unit) -> 'a option -> unitmay f (Some x) calls f x and may f None does nothing.
val map : ('a -> 'b) -> 'a option -> 'b optionmap f (Some x) returns Some (f x) and map None returns None.
val default : 'a -> 'a option -> 'adefault x (Some v) returns v and default x None returns x.
val map_default : ('a -> 'b) -> 'b -> 'a option -> 'bmap_default f x (Some v) returns f v and map_default f x None
returns x.
val is_none : 'a option -> boolis_none None returns true otherwise it returns false.
val is_some : 'a option -> boolis_some (Some x) returns true otherwise it returns false.
val get : 'a option -> 'aget (Some x) returns x and get None raises No_value.
exception No_value
Raised when calling get None.