How to implement collections (Set, List, Map) in JavaScript ?

[Luke Matuszewski]

Hej everybody.

I am writing a lot of code in JavaScript, and my code begins too look
to complicated... My work would be more effective is i could somehow
emulate Sets, Lists and Maps especially some of its operations.

Set - A collection that contains no duplicate elements (and its
elements may be everything: strings, function references, DOM element
references etc.);

List - An ordered collection (also known as a sequence) (and again
its elements may be everything: strings, function references, DOM
element references etc.);

Map - An object that maps keys to values. A map cannot contain
duplicate keys; each key can map to at most one value;

Can anyone point me to relevant URL's ? I know it is a lot to ask at
one post, but any clues would help.

B.R.
Luke Matuszewski.

 

[Thomas 'PointedEars' Lahn]

I am writing a lot of code in JavaScript, and my code begins too look
to complicated... My work would be more effective is i could somehow
emulate Sets, Lists and Maps especially some of its operations.

Set - A collection that contains no duplicate elements (and its
elements may be everything: strings, function references, DOM element
references etc.);

You are looking for any native ECMAScript object or a user-defined object
derived from it. You will need a setter, maybe using a hash function
applied on elements to be added to compute the respective property name,
to make sure no duplicate can be created within the data structure.

List - An ordered collection (also known as a sequence) (and again
its elements may be everything: strings, function references, DOM
element references etc.);

You are looking for Array objects, or any native ECMAScript object or a
user-defined object derived from it that refers to Array objects with
one of its properties. You will have to define a getter that considers
elements with a special value (for example `undefined') as an indicator
that the next/previous "list element" should be accessed instead.

Map - An object that maps keys to values. A map cannot contain
duplicate keys; each key can map to at most one value;

You are looking for any native ECMAScript object, or a user-defined object
derived from it.

In all cases, unless said otherwise, I recommend to use Object objects as
prototype, because they provide the least number of built-in properties,
which minimizes the risk of a property name collision and the size of the
memory footprint of the user-defined object.

<URL:http://pointedears.de/scripts/collection.js> maybe helps you to
implement this.


PointedEars