API / Belt / Hashset

You are viewing docs for an older version of Rescript.
Go to latest version.

HashSet

A mutable Hash set which allows customized hash behavior.

All data are parameterized by not its only type but also a unique identity in the time of initialization, so that two HashSets of ints initialized with different hash functions will have different type.

Examples

RESCRIPT
module I0 = unpack(
  Belt.Id.hashableU(
    ~hash=(. a: int) => land(a, 65535),
    ~eq=(. a, b) => a == b,
  )
)

let s0 = Belt.HashSet.make(~id=module(I0), ~hintSize=40)

module I1 = unpack(
  Belt.Id.hashableU(
    ~hash=(. a: int) => land(a, 255),
    ~eq=(. a, b) => a == b,
  )
)

let s1 = Belt.HashSet.make(~id=module(I1), ~hintSize=40)

Belt.HashSet.add(s1, 0)
Belt.HashSet.add(s1, 1)

The invariant must be held: for two elements who are equal, their hashed value should be the same.

Here the compiler would infer s0 and s1 having different type so that it would not mix.

Examples

RESCRIPT
let s0: Belt.HashSet.t<int, I0.identity>
let s1: Belt.HashSet.t<int, I1.identity>

We can add elements to the collection (see last two lines in the example above). Since this is an mutable data structure, s1 will contain two pairs.

t

RESCRIPT
type t<'a, 'id>

id

RESCRIPT
type id<'a, 'id> = Belt_Id.hashable<'a, 'id>

The type of hash tables from type 'a to type 'b.

make

RESCRIPT
let make: (~hintSize: int, ~id: id<'a, 'id>) => t<'a, 'id>

clear

RESCRIPT
let clear: t<'a, 'id> => unit

isEmpty

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

add

RESCRIPT
let add: (t<'a, 'id>, 'a) => unit

copy

RESCRIPT
let copy: t<'a, 'id> => t<'a, 'id>

has

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

remove

RESCRIPT
let remove: (t<'a, 'id>, 'a) => unit

forEachU

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

forEach

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

Order unspecified.

reduceU

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

reduce

RESCRIPT
let reduce: (t<'a, 'id>, 'c, ('c, 'a) => 'c) => 'c

Order unspecified.

size

RESCRIPT
let size: t<'a, 'id> => int

logStats

RESCRIPT
let logStats: t<'a, 'b> => unit

toArray

RESCRIPT
let toArray: t<'a, 'id> => array<'a>

fromArray

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

mergeMany

RESCRIPT
let mergeMany: (t<'a, 'id>, array<'a>) => unit

getBucketHistogram

RESCRIPT
let getBucketHistogram: t<'a, 'b> => array<int>