Set

An immutable sorted set module which allows customized compare behavior.

The implementation uses balanced binary trees, and therefore searching and insertion take time logarithmic in the size of the map.

For more info on this module's usage of identity, make and others, please see the top level documentation of Belt, A special encoding for collection safety.

Examples

RES
module PairComparator = Belt.Id.MakeComparable({
  type t = (int, int)
  let cmp = ((a0, a1), (b0, b1)) =>
    switch Pervasives.compare(a0, b0) {
    | 0 => Pervasives.compare(a1, b1)
    | c => c
    }
})

let mySet = Belt.Set.make(~id=module(PairComparator))
let mySet2 = Belt.Set.add(mySet, (1, 2))

Note: This module's examples will assume a predeclared module for integers called IntCmp. It is declared like this:

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

add

RES

let add: (t<'value, 'id>, 'value) => t<'value, 'id>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.make(~id=module(IntCmp))

let s1 = s0->Belt.Set.add(1)
let s2 = s1->Belt.Set.add(2)
let s3 = s2->Belt.Set.add(2)

s0->Belt.Set.toArray == []
s1->Belt.Set.toArray == [1]
s2->Belt.Set.toArray == [1, 2]
s3->Belt.Set.toArray == [1, 2]
s2 == s3

checkInvariantInternal

RES

let checkInvariantInternal: t<'a, 'b> => unit

throw when invariant is not held

cmp

RES

let cmp: (t<'value, 'id>, t<'value, 'id>) => 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.

diff

RES

let diff: (t<'value, 'id>, t<'value, 'id>) => t<'value, 'id>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))
let s1 = Belt.Set.fromArray([5, 2, 3, 1, 5, 4], ~id=module(IntCmp))

Belt.Set.diff(s0, s1)->Belt.Set.toArray == [6]

Belt.Set.diff(s1, s0)->Belt.Set.toArray == [1, 4]

eq

RES

let eq: (t<'value, 'id>, t<'value, 'id>) => bool

Checks if two sets are equal.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3], ~id=module(IntCmp))
let s1 = Belt.Set.fromArray([3, 2, 5], ~id=module(IntCmp))

Belt.Set.eq(s0, s1) == true

every

RES

let every: (t<'value, 'id>, 'value => bool) => bool

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let isEven = x => mod(x, 2) == 0

let s0 = Belt.Set.fromArray([2, 4, 6, 8], ~id=module(IntCmp))
s0->Belt.Set.every(isEven) == true

everyU

Deprecated

Use every instead

RES

let everyU: (t<'value, 'id>, 'value => bool) => bool

forEach

RES

let forEach: (t<'value, 'id>, 'value => unit) => unit

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))

let acc = ref(list{})

s0->Belt.Set.forEach(x => {
  acc := Belt.List.add(acc.contents, x)
})

acc.contents == list{6, 5, 3, 2}

forEachU

Deprecated

Use forEach instead

RES

let forEachU: (t<'value, 'id>, 'value => unit) => unit

Same as forEach but takes uncurried functon.

fromArray

RES

let fromArray: (array<'value>, ~id: id<'value, 'id>) => t<'value, 'id>

Creates new set from array of elements.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([1, 3, 2, 4], ~id=module(IntCmp))

s0->Belt.Set.toArray == [1, 2, 3, 4]

fromSortedArrayUnsafe

RES

let fromSortedArrayUnsafe: (array<'value>, ~id: id<'value, 'id>) => t<'value, 'id>

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

get

RES

let get: (t<'value, 'id>, '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.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([1, 2, 3, 4, 5], ~id=module(IntCmp))

s0->Belt.Set.get(3) == Some(3)
s0->Belt.Set.get(20) == None

getData

RES

let getData: t<'value, 'id> => Belt_SetDict.t<'value, 'id>

Advanced usage only

Returns the raw data (detached from comparator), but its type is still manifested, so that user can pass identity directly without boxing.

getExn

RES

let getExn: (t<'value, 'id>, 'value) => 'value

Same as get but throw when element does not exist.

getId

RES

let getId: t<'value, 'id> => id<'value, 'id>

Advanced usage only

Returns the identity of set.

getOrThrow

RES

let getOrThrow: (t<'value, 'id>, 'value) => 'value

Same as get but throw when element does not exist.

getUndefined

RES

let getUndefined: (t<'value, 'id>, 'value) => Js.undefined<'value>

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

has

RES

let has: (t<'value, 'id>, 'value) => bool

Checks if element exists in set.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let set = Belt.Set.fromArray([1, 4, 2, 5], ~id=module(IntCmp))

set->Belt.Set.has(3) == false
set->Belt.Set.has(1) == true

id

RES

type id<'value, 'id> = Belt_Id.comparable<'value, 'id>

The identity needed for making a set from scratch

intersect

RES

let intersect: (t<'value, 'id>, t<'value, 'id>) => t<'value, 'id>

Returns intersection of two sets.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))
let s1 = Belt.Set.fromArray([5, 2, 3, 1, 5, 4], ~id=module(IntCmp))

let intersect = Belt.Set.intersect(s0, s1)

intersect->Belt.Set.toArray == [2, 3, 5]

isEmpty

RES

let isEmpty: t<'a, 'b> => bool

Checks if set is empty.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let empty = Belt.Set.fromArray([], ~id=module(IntCmp))
let notEmpty = Belt.Set.fromArray([1], ~id=module(IntCmp))

Belt.Set.isEmpty(empty) == true
Belt.Set.isEmpty(notEmpty) == false

keep

RES

let keep: (t<'value, 'id>, 'value => bool) => t<'value, 'id>

Returns the set of all elements that satisfy the predicate.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let isEven = x => mod(x, 2) == 0

let s0 = Belt.Set.fromArray([1, 2, 3, 4, 5], ~id=module(IntCmp))
let s1 = s0->Belt.Set.keep(isEven)

s1->Belt.Set.toArray == [2, 4]

keepU

Deprecated

Use keep instead

RES

let keepU: (t<'value, 'id>, 'value => bool) => t<'value, 'id>

make

RES

let make: (~id: id<'value, 'id>) => t<'value, 'id>

Creates a new set by taking in the comparator

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let set = Belt.Set.make(~id=module(IntCmp))

Belt.Set.isEmpty(set) == true

maximum

RES

let maximum: t<'value, 'id> => option<'value>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.make(~id=module(IntCmp))
let s1 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0->Belt.Set.maximum == None
s1->Belt.Set.maximum == Some(5)

maxUndefined

RES

let maxUndefined: t<'value, 'id> => Js.undefined<'value>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.make(~id=module(IntCmp))
let s1 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0
->Belt.Set.maxUndefined
->Js.Undefined.toOption == None

s1
->Belt.Set.maxUndefined
->Js.Undefined.toOption == Some(5)

mergeMany

RES

let mergeMany: (t<'value, 'id>, array<'value>) => t<'value, 'id>

Adds each element of array to set. Unlike Belt.Set.add](#add), the reference of return value might be changed even if all values in array already exist in set

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let set = Belt.Set.make(~id=module(IntCmp))

let newSet = set->Belt.Set.mergeMany([5, 4, 3, 2, 1])

newSet->Belt.Set.toArray == [1, 2, 3, 4, 5]

minimum

RES

let minimum: t<'value, 'id> => option<'value>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.make(~id=module(IntCmp))
let s1 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0->Belt.Set.minimum == None
s1->Belt.Set.minimum == Some(1)

minUndefined

RES

let minUndefined: t<'value, 'id> => Js.undefined<'value>

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.make(~id=module(IntCmp))
let s1 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0->Belt.Set.minUndefined->Js.Undefined.toOption == None
s1->Belt.Set.minUndefined->Js.Undefined.toOption == Some(1)

packIdData

RES

let packIdData: (
  ~id: id<'value, 'id>,
  ~data: Belt_SetDict.t<'value, 'id>,
) => t<'value, 'id>

Advanced usage only

Returns the packed collection.

partition

RES

let partition: (
  t<'value, 'id>,
  'value => bool,
) => (t<'value, 'id>, t<'value, 'id>)

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.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let isOdd = x => mod(x, 2) != 0

let s0 = Belt.Set.fromArray([1, 2, 3, 4, 5], ~id=module(IntCmp))
let (s1, s2) = s0->Belt.Set.partition(isOdd)

s1->Belt.Set.toArray == [1, 3, 5]
s2->Belt.Set.toArray == [2, 4]

partitionU

Deprecated

Use partition instead

RES

let partitionU: (
  t<'value, 'id>,
  'value => bool,
) => (t<'value, 'id>, t<'value, 'id>)

reduce

RES

let reduce: (t<'value, 'id>, '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.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))
s0->Belt.Set.reduce(list{}, (acc, element) => acc->Belt.List.add(element)) == list{6, 5, 3, 2}

reduceU

Deprecated

Use reduce instead

RES

let reduceU: (t<'value, 'id>, 'a, ('a, 'value) => 'a) => 'a

remove

RES

let remove: (t<'value, 'id>, 'value) => t<'value, 'id>

Removes element from set. If element did not exist in set, value is unchanged.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([2, 3, 1, 4, 5], ~id=module(IntCmp))
let s1 = s0->Belt.Set.remove(1)
let s2 = s1->Belt.Set.remove(3)
let s3 = s2->Belt.Set.remove(3)

s1->Belt.Set.toArray == [2, 3, 4, 5]
s2->Belt.Set.toArray == [2, 4, 5]
s2 == s3

removeMany

RES

let removeMany: (t<'value, 'id>, array<'value>) => t<'value, 'id>

Removes each element of array from set. Unlike remove, the reference of return value might be changed even if none of values in array existed in set.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let set = Belt.Set.fromArray([1, 2, 3, 4], ~id=module(IntCmp))

let newSet = set->Belt.Set.removeMany([5, 4, 3, 2, 1])

newSet->Belt.Set.toArray == []

size

RES

let size: t<'value, 'id> => int

Returns size of the set.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([1, 2, 3, 4], ~id=module(IntCmp))

s0->Belt.Set.size == 4

some

RES

let some: (t<'value, 'id>, 'value => bool) => bool

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let isOdd = x => mod(x, 2) != 0

let s0 = Belt.Set.fromArray([1, 2, 4, 6, 8], ~id=module(IntCmp))
s0->Belt.Set.some(isOdd) == true

someU

Deprecated

Use some instead

RES

let someU: (t<'value, 'id>, 'value => bool) => bool

split

RES

let split: (
  t<'value, 'id>,
  'value,
) => ((t<'value, 'id>, t<'value, 'id>), bool)

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

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([1, 2, 3, 4, 5], ~id=module(IntCmp))

let ((smaller, larger), present) = s0->Belt.Set.split(3)

present == true
smaller->Belt.Set.toArray == [1, 2]
larger->Belt.Set.toArray == [4, 5]

subset

RES

let subset: (t<'value, 'id>, t<'value, 'id>) => bool

Checks if second set is subset of first set.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))
let s1 = Belt.Set.fromArray([5, 2, 3, 1, 5, 4], ~id=module(IntCmp))
let s2 = Belt.Set.intersect(s0, s1)

Belt.Set.subset(s2, s0) == true
Belt.Set.subset(s2, s1) == true
Belt.Set.subset(s1, s0) == false

t

RES

type t<'value, 'identity>

'value is the element type

'identity the identity of the collection

toArray

RES

let toArray: t<'value, 'id> => array<'value>

Returns array of ordered set elements.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0->Belt.Set.toArray == [1, 2, 3, 5]

toList

RES

let toList: t<'value, 'id> => list<'value>

Returns list of ordered set elements.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([3, 2, 1, 5], ~id=module(IntCmp))

s0->Belt.Set.toList == list{1, 2, 3, 5}

union

RES

let union: (t<'value, 'id>, t<'value, 'id>) => t<'value, 'id>

Returns union of two sets.

Examples

RES
module IntCmp = Belt.Id.MakeComparable({
  type t = int
  let cmp = Pervasives.compare
})

let s0 = Belt.Set.fromArray([5, 2, 3, 5, 6], ~id=module(IntCmp))
let s1 = Belt.Set.fromArray([5, 2, 3, 1, 5, 4], ~id=module(IntCmp))
let union = Belt.Set.union(s0, s1)

union->Belt.Set.toArray == [1, 2, 3, 4, 5, 6]