String.Set
String sets.
include Set.S with type elt := string and type t := set
val empty : set
The empty set.
val is_empty : set -> bool
Test whether a set is empty or not.
val mem : string -> set -> 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 (the result of the function is then physically equal to s
).
val singleton : string -> set
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 (the result of the function is then physically equal to s
).
Set difference: diff s1 s2
contains the elements of s1
that are not in s2
.
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.
val iter : (string -> unit) -> set -> 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.
map f s
is the set whose elements are f a0
,f a1
... f
aN
, where a0
,a1
...aN
are the elements of s
.
The elements are passed to f
in increasing order with respect to the ordering over the type of the elements.
If no element of s
is changed by f
, s
is returned unchanged. (If each output of f
is physically equal to its input, the returned set is physically equal to s
.)
val fold : (string -> 'a -> 'a) -> set -> 'a -> 'a
fold f s init
computes (f xN ... (f x2 (f x1 init))...)
, where x1 ... xN
are the elements of s
, in increasing order.
val for_all : (string -> bool) -> set -> bool
for_all f s
checks if all elements of the set satisfy the predicate f
.
val exists : (string -> bool) -> set -> bool
exists f s
checks if at least one element of the set satisfies the predicate f
.
filter f s
returns the set of all elements in s
that satisfy predicate f
. If f
satisfies every element in s
, s
is returned unchanged (the result of the function is then physically equal to s
).
filter_map f s
returns the set of all v
such that f x = Some v
for some element x
of s
.
For example,
filter_map (fun n -> if n mod 2 = 0 then Some (n / 2) else None) s
is the set of halves of the even elements of s
.
If no element of s
is changed or dropped by f
(if f x = Some x
for each element x
), then s
is returned unchanged: the result of the function is then physically equal to s
.
partition f s
returns a pair of sets (s1, s2)
, where s1
is the set of all the elements of s
that satisfy the predicate f
, and s2
is the set of all the elements of s
that do not satisfy f
.
val cardinal : set -> int
Return the number of elements of a set.
val elements : set -> string 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 Stdlib.Set.Make
.
val min_elt_opt : set -> string option
Return the smallest element of the given set (with respect to the Ord.compare
ordering), or None
if the set is empty.
val max_elt_opt : set -> string option
Same as min_elt_opt
, but returns the largest element of the given set.
val choose_opt : set -> string option
Return one element of the given set, or None
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 find_opt : string -> set -> string option
find_opt x s
returns the element of s
equal to x
(according to Ord.compare
), or None
if no such element exists.
val find_first : (string -> bool) -> set -> string
find_first f s
, where f
is a monotonically increasing function, returns the lowest element e
of s
such that f e
, or raises Not_found
if no such element exists.
For example, find_first (fun e -> Ord.compare e x >= 0) s
will return the first element e
of s
where Ord.compare e x >= 0
(intuitively: e >= x
), or raise Not_found
if x
is greater than any element of s
.
val find_first_opt : (string -> bool) -> set -> string option
find_first_opt f s
, where f
is a monotonically increasing function, returns an option containing the lowest element e
of s
such that f e
, or None
if no such element exists.
val find_last : (string -> bool) -> set -> string
find_last f s
, where f
is a monotonically decreasing function, returns the highest element e
of s
such that f e
, or raises Not_found
if no such element exists.
val find_last_opt : (string -> bool) -> set -> string option
find_last_opt f s
, where f
is a monotonically decreasing function, returns an option containing the highest element e
of s
such that f e
, or None
if no such element exists.
to_seq_from x s
iterates on a subset of the elements of s
in ascending order, from x
or above.
type t = set
val min_elt : set -> string option
Exception safe Set.S.min_elt
.
val max_elt : set -> string option
Exception safe Set.S.max_elt
.
val choose : set -> string option
Exception safe Set.S.choose
.
val find : string -> set -> string option
Exception safe Set.S.find
.
val get : string -> set -> string
get
is like Set.S.find
but
val of_list : string list -> set
of_list ss
is a set from the list ss
.
val of_stdlib_set : Set.Make(String).t -> set
of_stdlib_set s
is a set from the stdlib-compatible set s
.
val to_stdlib_set : set -> Set.Make(String).t
to_stdlib_set s
is the stdlib-compatible set equivalent to s
.
val pp :
?sep:(Format.formatter -> unit -> unit) ->
(Format.formatter -> string -> unit) ->
Format.formatter ->
set ->
unit
pp ~sep pp_elt ppf ss
formats the elements of ss
on ppf
. Each element is formatted with pp_elt
and elements are separated by ~sep
(defaults to Format.pp_print_cut
. If the set is empty leaves ppf
untouched.
val dump : Format.formatter -> set -> unit
dump ppf ss
prints an unspecified representation of ss
on ppf
.