Ordered Fast Lookup Map

Map with order functionality, providing fast look ups and ordering in the same time with O(n) complexity. Newer TS implementation. DeepClones with typesafety. Customizable validator/marshaller and deepClone available.

Installation

npm install ordered-fast-lookup-map

Usage

Compatibility mode

Runs with default validator and deepClone set to false;

var orderedMap = require("ordered-fast-lookup-map")
var userMap = new orderedMap();

TS / Types

We are now providing the types in the lib.

Available methods

Constructor

• constructor(keys?: NumberOrString[] | number[], values?: T[], options: IOFMLoptions<T> = { deepClone: false }) - when supplied with keys and values initiates structure and perform push on pair of keys. Exampple: var hashMap = OrderedTyoedFastLookupMap<string>([1,2,3],["a","b","c"]);. Additionally options:IOFMLoptions object can be passed, to set custom validator, to set deep clone and provide custom deep link handler.

Add methods

• set(key: NumberOrString, value: T) sets the value on the end of structure
• push(key: NumberOrString, value: T) alias for set
• unshift(key: NumberOrString, value: T) sets the value on the beginning of structure
• arbitrarySetAfter(afterKey: NumberOrString, key: NumberOrString, value: T)sets the value after arbitrary supplied keys. If the arbitrary key is not found it throws Error.
• arbitrarySetBefore(beforeKey: NumberOrString, key: NumberOrString, value: T)sets the value before arbitrary supplied keys. If the arbitrary key is not found it throws Error.

Note if inserting undefined any method will throw exception. Please use null instead. Or change the validator methods. Validator now can either throw or return true/false. This applies to all places where method is marked as throwable

Remove & Retrieve methods

• remove(key: NumberOrString) remove arbitrary value on the key. If the arbitrary key is not found it throwsError.
• pop(): T returns last element of structure and removes it. If list is empty returns undefined
• shift(): T returns first element of structure and removes it. If list is empty returns undefined
• get(key: NumberOrString): T returns value on the key without deleting it (return reference). If element is not found returns undefined
• has(key: NumberOrString): boolean checks if key exists (true/false)

Iteration Methods

• forEach(callback: IteratorCallback<T>): void for each element in asc order executes user supplied function(index,value,validatorFunction). To break in user function return true. We are now exposing the validator method out.
• forEachReverse(callback: IteratorCallback<T>): voidfor each element in desc order executes user supplied function(index,value,validatorFunction). To break in user function return true. We are now exposing the validator method out.

Validator and deepClone

• private validator(value: T): void | boolean by default, throws error is value is undefined. Can be replaced with IOFMLoptions

• private deepCloneMethod(val: T): T when deepClone is set to true (by default is false) this gets executed to clone object with keeping the constructor.name to preserve es6 object type/instance type. Can be replaced with IOFMLoptions

---

Inhouse types

type IteratorCallback<T> = (key: string, value: T, validator: IValidatorFunction<T>) => boolean;
type IValidatorFunction<T> = (value: T) => void | boolean;
type IDeepCloneFunction<T> = (value: T) => T;
type NumberOrString = string | number;

type IOFMLoptions<T> = {
    validator?: IValidatorFunction<T>
    deepClone?: boolean // default to false
    deepCloneMethod?: IDeepCloneFunction<T>

}

---

Migration / Example use

New TS implementation should work as previous v1.1.2 when accessed through require. It assumes OrderedTyoedFastLookupMap<any> with default validator that throws error only when you try to set undefined. Also the key is always forced to be a string in the map (this might be breaking for some).

import { OrderedTypedFastLookupMap, OrderedFastLookupMap } from "ordered-fast-lookup-map/lib";

// this is equivalent to const oflm = new OrderedFastLookupMap([`key`], [[{ "foo": "bar" }]]);
const oflm = new OrderedTypedFastLookupMap<any[]>([`key`], [[{ "foo": "bar" }]]);

console.log(oflm._array) // ["key"];
console.log(oflm.map); // { "key": [{ "foo": "bar" }] }

when imported in TS should allow for strict control of stored types, and the validator method. validator now can throw(default) or return true/false.

import { OrderedTyoedFastLookupMap, IOFMLoptions } from "../lib";

class testClass {
    constructor(public x: string) { }
}

class testClassWrong {
    constructor(public x: string) { }
}


const foo = new testClass('bar');
const noo = new testClassWrong('bar');

// adds foo t map
const oflm =  new OrderedTyoedFastLookupMap<testClass>([1], foo);

...

// ts error
const fail = new OrderedTyoedFastLookupMap<testClass>([1], noo);

...

// silently fails to add and just intiates the map
const fail = new OrderedTyoedFastLookupMap<testClass>([1], <any>noo);

...

// changes default validator
const opts: IOFMLoptions<testClass> = {
    validator: (val) => {
        if (!(<any>val instanceof testClass)) {
            return false;
        }
        return true;
    }
};


// silently fails to add and just intiates the map
const oflmValidatr = new OrderedTyoedFastLookupMap<testClass>([1], <testClass>noo, opts);

...

// changes default validator
const opts: IOFMLoptions<testClass> = {
    validator: (val) => {
        return true;
    }
};


// This will allow to create testClassWrong in the map and ignore marshalling
// checks, ts still will assumed the templated type
const oflmValidatr = new OrderedTyoedFastLookupMap<testClass>([1], <testClass>noo, opts);

...

const opts: IOFMLoptions<testClass> = {
    // deepCloneMethod <====== hookup custom method
    deepClone: true,
    validator: (val) => {
        if (!(<any>val instanceof testClass)) {
            return false;
        }
        return true;
    }
};