package elm_core
Library
Module
Module type
Parameter
Class
Class type
Sets over ordered types.
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.
The type of the set elements.
val empty : 'elt t
The empty set.
val is_empty : 'elt t -> bool
Test whether a set is empty or not.
val mem : 'elt -> 'elt t -> bool
mem x s
tests whether x
belongs to the set s
.
add x s
returns a set containing all elements of s
, plus x
. If x
was already in s
, s
is returned unchanged.
val singleton : 'elt -> 'elt t
singleton x
returns the one-element set containing only x
.
remove x s
returns a set containing all elements of s
, except x
. If x
was not in s
, s
is returned unchanged.
Total ordering between sets. Can be used as the ordering function for doing sets of sets.
equal s1 s2
tests whether the sets s1
and s2
are equal, that is, contain equal elements.
subset s1 s2
tests whether the set s1
is a subset of the set s2
.
val iter : ('elt -> unit) -> 'elt 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 fold : ('elt -> 'a -> 'a) -> 'elt t -> 'a -> 'a
fold f s a
computes (f xN ... (f x2 (f x1 a))...)
, where x1 ... xN
are the elements of s
, in increasing order.
val for_all : ('elt -> bool) -> 'elt t -> bool
for_all p s
checks if all elements of the set satisfy the predicate p
.
val exists : ('elt -> bool) -> 'elt t -> bool
exists p s
checks if at least one element of the set satisfies the predicate p
.
filter p s
returns the set of all elements in s
that satisfy predicate p
.
partition p s
returns a pair of sets (s1, s2)
, where s1
is the set of all the elements of s
that satisfy the predicate p
, and s2
is the set of all the elements of s
that do not satisfy p
.
val cardinal : 'elt t -> int
Return the number of elements of a set.
val elements : 'elt t -> 'elt list
Return the list of all elements of the given set. The returned list is sorted in increasing order with respect to the ordering Ord.compare
, where Ord
is the argument given to Set.Make
.
val min_elt : 'elt t -> 'elt
Return the smallest element of the given set (with respect to the Ord.compare
ordering), or raise Not_found
if the set is empty.
val max_elt : 'elt t -> 'elt
Same as Set.S.min_elt
, but returns the largest element of the given set.
val choose : 'elt t -> 'elt
Return one element of the given set, or raise Not_found
if the set is empty. Which element is chosen is unspecified, but equal elements will be chosen for equal sets.
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 of_list : 'elt list -> 'elt t
val pp :
(Format.formatter -> 'elt -> unit) ->
Format.formatter ->
'elt t ->
unit