Module type Stack.S
include Invariant.S1 with type 'a t := 'a t
val invariant : 'a Base__.Invariant_intf.inv -> 'a t Base__.Invariant_intf.inv
fold
, iter
, find
, and find_map
visit the elements in order from the top of the stack to the bottom. to_list
and to_array
return the elements in order from the top of the stack to the bottom.
Iteration functions (iter
, fold
, etc.) have unspecified behavior (although they should still be memory-safe) when the stack is mutated while they are running (e.g. by having the passed-in function call push
or pop
on the stack).
include 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
returnsf (... f (f (f init e1) e2) e3 ...) en
, wheree1..en
are the elements oft
val fold_result : 'a t -> init:'accum -> f:('accum -> 'a -> ('accum, 'e) Result.t) -> ('accum, 'e) Result.t
fold_result t ~init ~f
is a short-circuiting version offold
that runs in theResult
monad. Iff
returns anError _
, that value is returned without any additional invocations off
.
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 offold
. Iff
returnsStop _
the computation ceases and results in that value. Iff
returnsContinue _
, the fold will proceed. Iff
never returnsStop _
, the final result is computed byfinish
.Example:
type maybe_negative = | Found_negative of int | All_nonnegative of { sum : int } (** [first_neg_or_sum list] returns the first negative number in [list], if any, otherwise returns the sum of the list. *) let first_neg_or_sum = List.fold_until ~init:0 ~f:(fun sum x -> if x < 0 then Stop (Found_negative x) else Continue (sum + x)) ~finish:(fun sum -> All_nonnegative { sum }) ;; let x = first_neg_or_sum [1; 2; 3; 4; 5] val x : maybe_negative = All_nonnegative {sum = 15} let y = first_neg_or_sum [1; 2; -3; 4; 5] val y : maybe_negative = Found_negative -3
val exists : 'a t -> f:('a -> bool) -> bool
Returns
true
if and only if there exists an element for which the provided function evaluates totrue
. 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 totrue
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__.Container_intf.Summable with type t = 'sum) -> 'a t -> f:('a -> 'sum) -> 'sum
Returns the sum of
f i
for alli
in the container.
val find : 'a t -> f:('a -> bool) -> 'a option
Returns as an
option
the first element for whichf
evaluates to true.
val find_map : 'a t -> f:('a -> 'b option) -> 'b option
Returns the first evaluation of
f
that returnsSome
, and returnsNone
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, orNone
if the collection is empty. In case of a tie, the first element encountered while traversing the collection is returned. The implementation usesfold
so it has the same complexity asfold
.
val max_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option
val of_list : 'a list -> 'a t
of_list l
returns a stack whose top is the first element ofl
and bottom is the last element ofl
.
val create : unit -> _ t
create ()
returns an empty stack.
val singleton : 'a -> 'a t
singleton a
creates a new stack containing onlya
.
val push : 'a t -> 'a -> unit
push t a
addsa
to the top of stackt
.
val pop : 'a t -> 'a option
pop t
removes and returns the top element oft
asSome a
, or returnsNone
ift
is empty.
val pop_exn : 'a t -> 'a
val top : 'a t -> 'a option
top t
returnsSome a
, wherea
is the top oft
, unlessis_empty t
, in which casetop
returnsNone
.
val until_empty : 'a t -> ('a -> unit) -> unit
until_empty t f
repeatedly pops an elementa
off oft
and runsf a
, untilt
becomes empty. It is fine iff
adds more elements tot
, in which case the most-recently-added element will be processed next.