API / Belt / MutableSetString

You are currently looking at the v6.0 - v8.2 docs (Reason v3.6 syntax edition). You can find the latest API docs here.

(These docs cover all versions between v3 to v8 and are equivalent to the old BuckleScript docs before the rebrand)

MutableSetString

This module is Belt.MutableSet specialized with key type to be a string type. It is more efficient in general, the API is the same with Belt.MutableSet except its key type is fixed, and identity is not needed (using the built-in one)

value

RE
type value = string;

The type of the set elements.

t

RE
type t;

The type of sets.

make

RE
let make: unit => t;

Returns empty set.

RE
let set = Belt.MutableSet.String.make();

fromArray

RE
let fromArray: array(value) => t;

Creates new set from array of elements.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "orange", "banana"|])

s0->Belt.MutableSet.String.toArray; /* [|"apple", "banana", "orange"|] */

fromSortedArrayUnsafe

RE
let fromSortedArrayUnsafe: array(value) => t;

The same as [fromArray][#fromarray] except it is after assuming the input array is already sorted.

copy

RE
let copy: t => t;

Returns copy of a set.

RE
let s0 = Belt.MutableSet.String.fromArray([|"orange", "apple"|])

let copied = s0->Belt.MutableSet.String.copy;
copied->Belt.MutableSet.String.toArray /* [|"apple", "orange"|] */

isEmpty

RE
let isEmpty: t => bool;

Checks if set is empty.

RE
let empty = Belt.MutableSet.String.fromArray([||]);
let notEmpty = Belt.MutableSet.String.fromArray([|"apple"|]);

Belt.MutableSet.String.isEmpty(empty); /* true */
Belt.MutableSet.String.isEmpty(notEmpty); /* false */

has

RE
let has: (t, value) => bool;

Checks if element exists in set.

RE
let set = Belt.MutableSet.String.fromArray([|"apple", "orange", "banana"|]);

set->Belt.MutableSet.String.has("strawberry") /* false */
set->Belt.MutableSet.String.has("apple") /* true */

add

RE
let add: (t, value) => unit;

Adds element to set. If element existed in set, value is unchanged.

RE
let s0 = Belt.MutableSet.String.make();
s0->Belt.MutableSet.String.add("apple");
s0->Belt.MutableSet.String.add("banana");
s0->Belt.MutableSet.String.add("banana");

s0->Belt.MutableSet.String.toArray; /* [|"apple", "banana"|] */

addCheck

RE
let addCheck: (t, value) => bool;

mergeMany

RE
let mergeMany: (t, array(value)) => unit;

Adds each element of array to set.

RE
let set = Belt.MutableSet.String.make();

set->Belt.MutableSet.String.mergeMany([|"apple", "banana", "orange", "strawberry"|]);
set->Belt.MutableSet.String.toArray; /* [|"apple", "banana", "orange", "strawberry"|] */

remove

RE
let remove: (t, value) => unit;

Removes element from set. If element wasn't existed in set, value is unchanged.

RE
let s0 = Belt.MutableSet.String.fromArray([|"orange", "banana", "apple"|]);
s0->Belt.MutableSet.String.remove("apple");
s0->Belt.MutableSet.String.remove("banana");
s0->Belt.MutableSet.String.remove("banana");

s0->Belt.MutableSet.String.toArray; /* [|"orange"|] */

removeCheck

RE
let removeCheck: (t, value) => bool;

removeMany

RE
let removeMany: (t, array(value)) => unit;

Removes each element of array from set.

RE
let set = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange"|]);

set->Belt.MutableSet.String.removeMany([|"strawberry", "apple", "banana", "orange"|]);
set->Belt.MutableSet.String.toArray; /* [||] */

union

RE
let union: (t, t) => t;

Returns union of two sets.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "carrot"|]);
let s1 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "strawberry"|]);
let union = Belt.MutableSet.String.union(s0, s1);
union->Belt.MutableSet.String.toArray; /* [|"apple", "banana", "carrot", "orange", "strawberry"|] */

intersect

RE
let intersect: (t, t) => t;

Returns intersection of two sets.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "carrot"|]);
let s1 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "strawberry"|]);
let intersect = Belt.MutableSet.String.intersect(s0, s1);
intersect->Belt.MutableSet.String.toArray; /* [|"apple", "banana", "orange"|] */

diff

RE
let diff: (t, t) => t;

Returns elements from first set, not existing in second set.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "carrot"|]);
let s1 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange", "strawberry"|]);
Belt.MutableSet.String.toArray(Belt.MutableSet.String.diff(s0, s1)); /* [|"carrot"|] */
Belt.MutableSet.String.toArray(Belt.MutableSet.String.diff(s1, s0)); /* [|"strawberry"|] */

subset

RE
let subset: (t, t) => bool;

Checks if second set is subset of first set.

RE
let s0 = Belt.MutableSet.String.fromArray([|"5", "2", "3", "5", "6"|]);
let s1 = Belt.MutableSet.String.fromArray([|"5", "2", "3", "1", "5", "4"|]);
let s2 = Belt.MutableSet.String.intersect(s0, s1);
Belt.MutableSet.String.subset(s2, s0); /* true */
Belt.MutableSet.String.subset(s2, s1); /* true */
Belt.MutableSet.String.subset(s1, s0); /* false */

cmp

RE
let cmp: (t, t) => int;

Total ordering between sets. Can be used as the ordering function for doing sets of sets. It compares size first and then iterates over each element following the order of elements.

eq

RE
let eq: (t, t) => bool;

Checks if two sets are equal.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);
let s1 = Belt.MutableSet.String.fromArray([|"orange", "apple"|]);

Belt.MutableSet.String.eq(s0, s1); /* true */

forEachU

RE
let forEachU: (t, [@bs] (value => unit)) => unit;

Same as forEach but takes uncurried functon.

forEach

RE
let forEach: (t, value => unit) => unit;

Applies function f in turn to all elements of set in increasing order.

RE
let s0 = Belt.MutableSet.String.fromArray([|"banana", "orange", "apple"|]);
let acc = ref([]);
s0->Belt.MutableSet.String.forEach(x => {
  acc := Belt.List.add(acc^, x)
});
acc; /* ["orange", "banana", "apple"] */

reduceU

RE
let reduceU: (t, 'a, [@bs] (('a, value) => 'a)) => 'a;

reduce

RE
let reduce: (t, 'a, ('a, value) => 'a) => 'a;

Applies function f to each element of set in increasing order. Function f has two parameters: the item from the set and an “accumulator”, which starts with a value of initialValue. reduce returns the final value of the accumulator.

Applies function f to each element of set in increasing order. Function f has two parameters: the item from the set and an “accumulator”, which starts with a value of initialValue. reduce returns the final value of the accumulator.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);
s0->Belt.MutableSet.String.reduce(0, (acc, element) =>
  acc + String.length(element)
); /* 11 */

everyU

RE
let everyU: (t, [@bs] (value => bool)) => bool;

every

RE
let every: (t, value => bool) => bool;

Checks if all elements of the set satisfy the predicate. Order unspecified.

RE
let hasAtLeastFiveChars = x => String.length(x) >= 5;

let s0 = Belt.MutableSet.String.fromArray([|"apple", "carrot"|]);
s0->Belt.MutableSet.String.every(hasAtLeastFiveChars); /* true */

someU

RE
let someU: (t, [@bs] (value => bool)) => bool;

some

RE
let some: (t, value => bool) => bool;

Checks if at least one element of the set satisfies the predicate.

RE
let hasFiveChars = x => String.length(x) == 5;

let s0 = Belt.MutableSet.String.fromArray([|"strawberry", "apple"|]);
s0->Belt.MutableSet.String.some(hasFiveChars); /* true */

keepU

RE
let keepU: (t, [@bs] (value => bool)) => t;

keep

RE
let keep: (t, value => bool) => t;

Returns the set of all elements that satisfy the predicate.

RE
let hasFiveChars = x => String.length(x) == 5;

let s0 = Belt.MutableSet.String.fromArray([|"apple", "orange", "banana"|]);
let s1 = s0->Belt.MutableSet.String.keep(hasFiveChars);

s1->Belt.MutableSet.String.toArray; /* [|"apple"|] */

partitionU

RE
let partitionU: (t, [@bs] (value => bool)) => (t, t);

partition

RE
let partition: (t, value => bool) => (t, t);

Returns a pair of sets, where first is the set of all the elements of set that satisfy the predicate, and second is the set of all the elements of set that do not satisfy the predicate.

RE
let hasFiveChars = x => String.length(x) == 5;

let s0 = Belt.MutableSet.String.fromArray([|"apple", "carrot"|]);
let (s1, s2) = s0->Belt.MutableSet.String.partition(hasFiveChars);

s1->Belt.MutableSet.String.toArray; /* [|"apple"|] */
s2->Belt.MutableSet.String.toArray; /* [|"carrot"|] */

size

RE
let size: t => int;

Returns size of the set.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple"|]);

s0->Belt.MutableSet.String.size; /* 1 */

toList

RE
let toList: t => list(value);

Returns list of ordered set elements.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "watermelon"|]);

s0->Belt.MutableSet.String.toList; /* ["apple", "watermelon"] */

toArray

RE
let toArray: t => array(value);

Returns array of ordered set elements.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "watermelon"|]);

s0->Belt.MutableSet.String.toArray; /* [|"apple", "watermelon"|] */

minimum

RE
let minimum: t => option(value);

Returns minimum value of the collection. None if collection is empty.

RE
let s0 = Belt.MutableSet.String.make();
let s1 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);

s0->Belt.MutableSet.String.minimum; /* None */
s1->Belt.MutableSet.String.minimum; /* Some("apple") */

minUndefined

RE
let minUndefined: t => Js.undefined(value);

Returns minimum value of the collection. undefined if collection is empty.

RE
let s0 = Belt.MutableSet.String.make();
let s1 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);

s0->Belt.MutableSet.String.minUndefined; /* undefined */
s1->Belt.MutableSet.String.minUndefined; /* "apple" */

maximum

RE
let maximum: t => option(value);

Returns maximum value of the collection. None if collection is empty.

RE
let s0 = Belt.MutableSet.String.make();
let s1 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);

s0->Belt.MutableSet.String.maximum; /* None */
s1->Belt.MutableSet.String.maximum; /* Some("orange") */

maxUndefined

RE
let maxUndefined: t => Js.undefined(value);

Returns maximum value of the collection. undefined if collection is empty.

RE
let s0 = Belt.MutableSet.String.make();
let s1 = Belt.MutableSet.String.fromArray([|"apple", "orange"|]);

s0->Belt.MutableSet.String.maxUndefined; /* undefined */
s1->Belt.MutableSet.String.maxUndefined; /* orange */

get

RE
let get: (t, value) => option(value);

Returns the reference of the value which is equivalent to value using the comparator specifiecd by this collection. Returns None if element does not exist.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "carrot"|]);

s0->Belt.MutableSet.String.get("carrot"); /* Some("carrot") */
s0->Belt.MutableSet.String.get("watermelon"); /* None */

getUndefined

RE
let getUndefined: (t, value) => Js.undefined(value);

Same as get but returns undefined when element does not exist.

getExn

RE
let getExn: (t, value) => value;

Same as get but raise when element does not exist.

split

RE
let split: (t, value) => ((t, t), bool);

Returns a tuple ((smaller, larger), present), present is true when element exist in set.

RE
let s0 = Belt.MutableSet.String.fromArray([|"apple", "banana", "orange"|]);

let ((smaller, larger), present) = s0->Belt.MutableSet.String.split("banana");

present; /* true */
smaller->Belt.MutableSet.String.toArray; /* [|"apple"|] */
larger->Belt.MutableSet.String.toArray; /* [|"orange"|] */

checkInvariantInternal

RE
let checkInvariantInternal: t => unit;

raise when invariant is not held