module BatSet:sig
..end
This module implements the set data structure, given a total ordering function over the set elements. All operations over sets are purely applicative (no side-effects). The implementation uses balanced binary trees, and is therefore reasonably efficient: insertion and membership take time logarithmic in the size of the set, for instance.
Note OCaml, Batteries Included, provides two implementations
of sets: polymorphic sets and functorized sets. Functorized sets
(see BatSet.S
and BatSet.Make
) are slightly more complex to use but offer
stronger type-safety. Polymorphic sets make it easier to shoot
yourself in the foot. In case of doubt, you should use functorized
sets.
The functorized set implementation is built upon Stdlib's
Set
module, but provides the complete interface.
Author(s): Xavier Leroy, Nicolas Cannasse, Markus Mottl, David Rajchenbach-Teller
module type OrderedType = BatInterfaces.OrderedType
Set.Make
.
module type S =sig
..end
Set.Make
.
module Make:
module Make2:
module Int:S
with type elt = int
module Int32:S
with type elt = int32
module Int64:S
with type elt = int64
module Nativeint:S
with type elt = nativeint
module Float:S
with type elt = float
module Char:S
with type elt = char
module String:S
with type elt = string
The definitions below describe the polymorphic set interface.
They are similar in functionality to the functorized BatSet.Make
module, but the compiler cannot ensure that sets using different
element ordering have different types: the responsibility of not
mixing non-sensical comparison functions together is to the
programmer. If in doubt, you should rather use the BatSet.Make
functor for additional safety.
type 'a
t
include BatEnum.Enumerable
include BatInterfaces.Mappable
val empty : 'a t
compare
as comparison functionval is_empty : 'a t -> bool
val singleton : 'a -> 'a t
val mem : 'a -> 'a t -> bool
mem x s
tests whether x
belongs to the set s
.val find : 'a -> 'a t -> 'a
find x s
returns the set element that compares equal to x
.Not_found
if no such element existsval add : 'a -> 'a t -> 'a t
add x s
returns a set containing all elements of s
,
plus x
. If x
was already in s
, s
is returned unchanged.val remove : 'a -> 'a t -> 'a t
remove x s
returns a set containing all elements of s
,
except x
. If x
was not in s
, s
is returned unchanged.val update : 'a -> 'a -> 'a t -> 'a t
update x y s
replace x
by y
in s
.
update
is faster when x
compares equal to y
according
to the comparison function used by your set.Not_found
if x
is not in s
.val union : 'a t -> 'a t -> 'a t
union s t
returns the union of s
and t
- the set containing
all elements in either s
and t
. The returned set uses t
's
comparison function. The current implementation works better for
small s
.val intersect : 'a t -> 'a t -> 'a t
intersect s t
returns a new set of those elements that are in
both s
and t
. The returned set uses s
's comparison function.val diff : 'a t -> 'a t -> 'a t
diff s t
returns the set of all elements in s
but not in
t
. The returned set uses s
's comparison function.val sym_diff : 'a t -> 'a t -> 'a t
sym_diff s t
returns the set of all elements in s
or t
but
not both, also known as the symmetric difference. This is the
same as diff (union s t) (inter s t)
. The returned set uses
s
's comparison function.val compare : 'a t -> 'a t -> int
val equal : 'a t -> 'a t -> bool
equal s1 s2
tests whether the sets s1
and s2
are
equal, that is, contain equal elements.val subset : 'a t -> 'a t -> bool
subset a b
returns true if a
is a subset of b
. O(|a|).val disjoint : 'a t -> 'a t -> bool
disjoint s1 s2
tests whether the sets s1
and s2
contain no
shared elements. (i.e. inter s1 s2
is empty.)val iter : ('a -> unit) -> 'a t -> unit
iter f s
applies f
in turn to all elements of s
.
The elements of s
are presented to f
in increasing order
with respect to the ordering over the type of the elements.val at_rank_exn : int -> 'a t -> 'a
at_rank_exn i s
returns element at rank i
in s
, that is
the i
-th element in increasing order
(the 0
-th element being the smallest element of s
).Not_found
if s = empty
.Invalid_argument
error_message if i < 0 || i >= cardinal s
val map : ('a -> 'b) -> 'a t -> 'b t
map f x
creates a new set with elements f a0
,
f a1
... f aN
, where a0
, a1
, ..., aN
are the
elements of x
.
This function places no restriction on f
; it can map multiple
input values to the same output value, in which case the
resulting set will have smaller cardinality than the input. f
does not need to be order preserving, although if it is, then
Incubator.op_map
may be more efficient.
val filter : ('a -> bool) -> 'a t -> 'a t
filter p s
returns the set of all elements in s
that satisfy predicate p
.val filter_map : ('a -> 'b option) -> 'a t -> 'b t
filter_map f m
combines the features of filter
and
map
. It calls calls f a0
, f a1
, f aN
where a0,a1..an
are the elements of m
and returns the set of pairs bi
such as f ai = Some bi
(when f
returns None
, the
corresponding element of m
is discarded).
The resulting map uses the polymorphic compare
function to
order elements.
val fold : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b
fold f s a
computes (f xN ... (f x1 (f x0 a))...)
,
where x0,x1..xN
are the elements of s
, in increasing order.val exists : ('a -> bool) -> 'a t -> bool
exists p s
checks if at least one element of
the set satisfies the predicate p
.val for_all : ('a -> bool) -> 'a t -> bool
val partition : ('a -> bool) -> 'a t -> 'a t * 'a t
val split : 'a -> 'a t -> 'a t * bool * 'a t
split x s
returns a triple (l, present, r)
, where
l
is the set of elements of s
that are
strictly less than x
;
r
is the set of elements of s
that are
strictly greater than x
;
present
is false
if s
contains no element equal to x
,
or true
if s
contains an element equal to x
.val split_opt : 'a -> 'a t -> 'a t * 'a option * 'a t
split_opt x s
returns a triple (l, maybe_v, r)
, where
l
is the set of elements of s
that are
strictly less than x
;
r
is the set of elements of s
that are
strictly greater than x
;
maybe_v
is None
if s
contains no element equal to x
,
or Some v
if s
contains an element v
that compares equal to x
.val split_lt : 'a -> 'a t -> 'a t * 'a t
split_lt x s
returns a pair of sets (l, r)
, such that
l
is the subset of s
with elements < x
;
r
is the subset of s
with elements >= x
.val split_le : 'a -> 'a t -> 'a t * 'a t
split_le x s
returns a pair of sets (l, r)
, such that
l
is the subset of s
with elements <= x
;
r
is the subset of s
with elements > x
.val cardinal : 'a t -> int
val elements : 'a t -> 'a list
val to_list : 'a t -> 'a list
elements
.val to_array : 'a t -> 'a array
to_list
but with an array instead of a list.val min_elt : 'a t -> 'a
Invalid_argument
if given an empty set.val pop_min : 'a t -> 'a * 'a t
let mini = min_elt s in (mini, remove mini s)
Since 2.4
Raises Not_found
if the set is empty.
val pop_max : 'a t -> 'a * 'a t
let maxi = max_elt s in (maxi, remove maxi s)
Since 2.4
Raises Not_found
if the set is empty.
val max_elt : 'a t -> 'a
Invalid_argument
if given an empty set.val choose : 'a t -> 'a
Invalid_argument
if given an empty set.val pop : 'a t -> 'a * 'a t
Not_found
if given an empty setval cartesian_product : 'a t -> 'b t -> ('a * 'b) t
val enum : 'a t -> 'a BatEnum.t
val of_enum : 'a BatEnum.t -> 'a t
val backwards : 'a t -> 'a BatEnum.t
Pervasives.compare
.val of_list : 'a list -> 'a t
val of_array : 'a array -> 'a t
val print : ?first:string ->
?last:string ->
?sep:string ->
('a BatInnerIO.output -> 'c -> unit) ->
'a BatInnerIO.output -> 'c t -> unit
module Infix:sig
..end
module Incubator:sig
..end
module PSet:sig
..end