Immutable Persistent Data Structures

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Simple Interactive JS Console

Immutable List

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List are singly linked lists which support efficient O(1) addition and removal from the front using unshift(value) and shift(). Wikipedia Persistent Data Structure Linked Lists

Example Code

var a = ImmutableList.of(0, 1, 2, 3);
var b = a.push(4, 5, 6);
a.toArray(); // -> [0, 1, 2, 3]
b.toArray(); // -> [0, 1, 2, 3, 4, 5, 6]
      

Immutable Vector

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Vectors are ordered indexed collections. Understanding Clojure's Persistent Vector

Example Code

var a = ImmutableVector.of(0, 1, 2, 3);
var b = a.push(4, 5, 6);
a.toArray(); // -> [0, 1, 2, 3]
b.toArray(); // -> [0, 1, 2, 3, 4, 5, 6]
      

Immutable HashMap

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HashMap is an unordered collection of (key, value) pairs. Understanding Clojure's Persistent HashMap

Example Code

var a = ImmutableHashMap.of({a: 0, b: 1});
var b = a.set("c", 2);
a.toObject(); // -> {a: 0, b: 1}
b.toObject(); // -> {a: 0, b: 1, c: 2}
      

Immutable Set

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Sets are a collection of unique values. It is a wrapper class where Set<V> = HashMap<V, Void>.

Example Code

var a = ImmutableSet.of(0, 1, 2, 3);
var b = a.set(2, 3, 4);
a.toArray(); // -> [0, 1, 2, 3]
b.toArray(); // -> [0, 1, 2, 3, 4]
      

Immutable Record

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A Record is a wrapper class around a HashMap with rescrited fields.

Example Code

var Person = ImmutableRecord({
    name: null
}, "Person");
var a = new Person({name: "Bob"});
var b = a.set("name", "Billy");
a.toObject(); // -> {name: "Bob"}
b.toObject(); // -> {name: "Billy"}