like-ar

Using objects like arrays with map, filter, forEach and others coming soon.

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Install

$ npm install like-ar

Usage

The function LikeAr wraps an object. The wraped object can be used like an array with some array functions: forEach, map, filter y join.

These functions receive a callback in the same way that the array version does.

var {LikeAr} = require('like-ar');

var object={
    lastName:'Perez',
    firstName:'Diego',
    phone:'+45-11-2222-3333'
}

LikeAr(object).forEach(function(value, attrName, object, position){
    console.log(position+'.',attrName,':',value);
});

console.log(
    LikeAr(object).filter(function(value, attrName){
        return attrName.contains('Name');
    }).map(function(value,attrName){
        return attrName+':'+value
    }).join(', ')
);

var objectUpperCase=LikeAr(object).map(v=>v.toUpperCase());

/* objectUpperCase =
var object={
    lastName:'PEREZ',
    firstName:'DIEGO',
    phone:'+45-11-2222-3333'
}
*/

API

likeAr(object)

The callback functions receive these parameters: value, key, the original object and the position (starting by 0). The functions that in the Array case returns Arrays returns a chainable object.

function	returned value
forEach(cb, this)	undefined
map(cb, this)	chainable object with the same keys and the value mapeds
filter(db, this)	chainable object with the same keys and values for only that key/value that returns true in the callback function
join(separator)	string with the join of the values
array()	array of values
keys()	array of keys
plain()	plain object without LikeAr functions

LikeAr(object).build(cb(value, key))

Builds a new object with new keys.

The callback function must return a {key: value} object to compose the final result.

var pairs=[{field:'lastName', value:'Perez'}, {field:'firstName', value:'Diego'}];

console.log(LikeAr(pairs).build(funciton(pair){ return {[pair.field]: pair.value}; ));
// {lastName: "Perez", firstName: "Diego"}

var toJoin=[{lastName:'Perez'}, {firstName:'Diego'}];

console.log(LikeAr(toJoin).build(funciton(objectWithOneKey){ return objectWithOneKey; ));
// {lastName: "Perez", firstName: "Diego"}

LikeAr.toPlainObject(array [,keyName [,valueName]])

LikeAr.toPlainObject(arrayOfKeys, arrayOfValues)

Returns a plain object from an array of pairs (or a pair of arrays) of key/values.

Default values: 0 and 1 if keyName is not set. "value" for valueName if keyName is set.

var {LikeAr} = require('like-ar');

var pairs=[['lastName', 'Perez'], ['firstName', 'Diego']];

console.log(LikeAr.toPlainObject(pairs));

var pairs=[{field:'lastName', value:'Perez'}, {field:'firstName', value:'Diego'}];

console.log(LikeAr.toPlainObject(pairs, 'field'));

LikeAr.createIndex(array:T[], keyName:string): Record<string, T>

Returns a plain object containing the same element indexed by keyName

var {LikeAr} = require('like-ar');

var persons=[{name:'Diego', lastName:'Rivera', age:30}, {name:'Frida', lastName:'Kahlo'}];

var idxPersons=LikeAr.createIndex(persons, 'lastName');

idxPersons.Kahlo.age=20;

console.log(persons[1].age); // 20

LikeAr.createIndex(array:T[], getKey:T => string): Record<string, T>

Returns a plain object containing the same element indexed by getKey(item)

var {LikeAr} = require('like-ar');

var persons=[{name:'Diego', lastName:'Rivera', age:30}, {name:'Frida', lastName:'Kahlo'}];

var idxPersons=LikeAr.createIndex(persons, (p) => p.name + p.lastName);

idxPersons.FridaKahlo.age=20;

console.log(persons[1].age); // 20

LikeAr.iterator(arrayOrObject: T[] | Record<K,T>): Iterator<T>

Returns an Iterator from an Array<T> or a Record<K,T>. If the parameter is an array the same array is returned. Otherwise it returns an iterator to the values of the object.

var {iterator} = require('like-ar');

function showValues(arrayOrObject: any[] | Record<any, any>){
    for (var value of iterator(arrayOrObject)) {
        console.log(value)
    }
}

LikeAr<K,T>(object:Record<K,Promise<T>>).awaitAll(): Promise<Record<K,T>>

It runs all promises in parallel. When all finished it retunrs an object with the same keys and the resolution of each promise. If some of the promises fails it will fail immediately.

var likear = require('like-ar').strict;

var sqls = {
    persons: 'select * from person',
    mascots: 'select * from mascot'
}

var data = await likear(sqls).map(async sql => db.query(sql)).awaitAll();

console.log(data);

LikeAr.empty(arrayOrObject: T[] | Record<K,T> | null): boolean

Returns false if the arreglo or object has at least one value. Returns true if it is empty (i.e. if the array is [] or the object is {} or null)

var {iterator, emtpy} = require('like-ar');

function showValues(arrayOrObject: any[] | Record<any, any> | null){
    if (empty(arrayOrObject)) {
        Console.log('EMPTY!')
    }
    for (var value of iterator(arrayOrObject)) {
        console.log(value)
    }
}

License

MIT