Option type.
include sig ... end
val hash_fold_t : (Base.Hash.state ‑> 'a ‑> Base.Hash.state) ‑> Base.Hash.state ‑> 'a t ‑> Base.Hash.state
val t_of_sexp : (Base.Sexp.t ‑> 'a) ‑> Base.Sexp.t ‑> 'a t
val sexp_of_t : ('a ‑> Base.Sexp.t) ‑> 'a t ‑> Base.Sexp.t
include Base.Container.S1 with type a t := a t
val mem : 'a t ‑> 'a ‑> equal:('a ‑> 'a ‑> bool) ‑> bool
Checks whether the provided element is there, using equal
.
val length : 'a t ‑> int
val is_empty : 'a t ‑> bool
val iter : 'a t ‑> f:('a ‑> unit) ‑> unit
val fold : 'a t ‑> init:'accum ‑> f:('accum ‑> 'a ‑> 'accum) ‑> 'accum
fold t ~init ~f
returns f (... f (f (f init e1) e2) e3 ...) en
, where e1..en
are the elements of t
val fold_result : 'a t ‑> init:'accum ‑> f:('accum ‑> 'a ‑> ('accum, 'e) Base.Result.t) ‑> ('accum, 'e) Base.Result.t
fold_result t ~init ~f
is a short-circuiting version of fold
that runs in the
Result
monad. If f
returns an Error _
, that value is returned without any
additional invocations of f
.
val fold_until : 'a t ‑> init:'accum ‑> f:('accum ‑> 'a ‑> ('accum, 'final) Base__.Container_intf.Continue_or_stop.t) ‑> finish:('accum ‑> 'final) ‑> 'final
fold_until t ~init ~f ~finish
is a short-circuiting version of fold
. If f
returns Stop _
the computation ceases and results in that value. If f
returns
Continue _
, the fold will proceed. If f
never returns Stop _
, the final result
is computed by finish
.
val exists : 'a t ‑> f:('a ‑> bool) ‑> bool
Returns true
if and only if there exists an element for which the provided
function evaluates to true
. This is a short-circuiting operation.
val for_all : 'a t ‑> f:('a ‑> bool) ‑> bool
Returns true
if and only if the provided function evaluates to true
for all
elements. This is a short-circuiting operation.
val count : 'a t ‑> f:('a ‑> bool) ‑> int
Returns the number of elements for which the provided function evaluates to true.
val sum : (module Base.Commutative_group.S with type t = 'sum) ‑> 'a t ‑> f:('a ‑> 'sum) ‑> 'sum
Returns the sum of f i
for all i
in the container.
val find : 'a t ‑> f:('a ‑> bool) ‑> 'a option
Returns as an option
the first element for which f
evaluates to true.
val find_map : 'a t ‑> f:('a ‑> 'b option) ‑> 'b option
Returns the first evaluation of f
that returns Some
, and returns None
if there
is no such element.
val to_list : 'a t ‑> 'a list
val to_array : 'a t ‑> 'a array
val min_elt : 'a t ‑> compare:('a ‑> 'a ‑> int) ‑> 'a option
Returns a minimum (resp maximum) element from the collection using the provided
compare
function, or None
if the collection is empty. In case of a tie, the first
element encountered while traversing the collection is returned. The implementation
uses fold
so it has the same complexity as fold
.
val max_elt : 'a t ‑> compare:('a ‑> 'a ‑> int) ‑> 'a option
include Base.Equal.S1 with type a t := a t
val equal : 'a Base.Equal.equal ‑> 'a t Base.Equal.equal
include Base.Invariant.S1 with type a t := a t
val invariant : 'a Base__.Invariant_intf.inv ‑> 'a t Base__.Invariant_intf.inv
Options form a monad, where return x = Some x
, (None >>= f) = None
, and (Some x
>>= f) = f x
.
include Base.Monad.S with type a t := a t
include Base__.Monad_intf.S_without_syntax with type a t := a t
include Base__.Monad_intf.Infix with type a t := a t
module Monad_infix : Base__.Monad_intf.Infix with type a t := a t
val value_map : 'a t ‑> default:'b ‑> f:('a ‑> 'b) ‑> 'b
value_map ~default ~f
is the same as function Some x -> f x | None -> default
.
val value_exn : ?here:Base__.Source_code_position0.t ‑> ?error:Base.Error.t ‑> ?message:string ‑> 'a t ‑> 'a
value_exn (Some x)
= x
. value_exn None
raises an error whose contents contain
the supplied ~here
, ~error
, and message
, or a default message if none are
supplied.
val some : 'a ‑> 'a t
val some_if : bool ‑> 'a ‑> 'a t
merge a b ~f
merges together the values from a
and b
using f
. If both a
and
b
are None
, returns None
. If only one is Some
, returns that one, and if both
are Some
, returns Some
of the result of applying f
to the contents of a
and
b
.
val try_with : (unit ‑> 'a) ‑> 'a t
try_with f
returns Some x
if f
returns x
and None
if f
raises an
exception. See Result.try_with
if you'd like to know which exception.
val validate : none:unit Base.Validate.check ‑> some:'a Base.Validate.check ‑> 'a t Base.Validate.check