@kingjs/linq

Exports all @kingjs/linq.* functionality in one package.

Usage

Join pets to their owners, sorted by last name, then first name, excluding fishes, like this:

var linq = require('@kingjs/linq');
var sequence = require('@kingjs/enumerable.create');
var apply = require('@kingjs/apply');

var people = sequence(
  { firstName: 'Bob', lastName: 'Smith', id: 0 },
  { firstName: 'Alice', lastName: 'Smith', id: 1 },
  { firstName: 'Chris', lastName: 'King', id: 2 },
);

var pets = sequence(
  { name: 'Tiger', type: 'dog', ownerId: 0 },
  { name: 'Spike', type: 'dog', ownerId: 0 },
  { name: 'Fluffy', type: 'cat', ownerId: 1 },
  { name: 'Bubbles', type: 'fish', ownerId: 2 },
);

apply.call(people,
  linq.orderBy, [ function(x) { return x.lastName; } ],
  linq.thenBy, [ function(x) { return x.firstName; } ],
  linq.join, [
    pets, 
    function(x) { return x.id; },
    function(x) { return x.ownerId; },
    function(owner, pet) { return { owner: owner, pet: pet } }
  ],
  linq.where, [ function(x) { return x.pet.type != 'fish'; } ],
  linq.select, [
    function(x) { 
      var owner = x.owner;
      var pet = x.pet;

      return owner.firstName + " " + owner.lastName + 
        ' owns a ' + pet.type + ' named ' + pet.name + '.';
    },
  ],
  linq.toArray, [],
  Array.prototype.join, ['\n']
);

result:

Alice Smith owns a cat named Fluffy. 
Bob Smith owns a dog named Tiger. 
Bob Smith owns a dog named Spike.

API

| Search | Aggregate | Set | Generator | Accrete | |---|---|---|---|---| |all|aggregate|distinct|range|append| |any|average|except|repeat|concat| |contains|count|intersect|empty|prepend| |elementAtOrUndef|max|union| |firstOrUndef|min|| |lastOrUndef|sum| |singleOrUndef|equal

| Sort | Filter | Join | Transform | Container | |---|---|---|---|---| |orderBy|skip|groupBy|select|toArray| |orderByDesc|skipWhile|groupJoin|selectMany|toDictionary| |thenBy|take|join||toLookup| |thenByDesc|takeWhile|zip| ||where|

Install

With npm installed, run

$ npm install @kingjs/link

Remarks

See @kingjs/apply to understand the benefit of the "odd" apply convention. Basically, it allows for the separation of data from algorithm; Data and algorithm separation cannot be achieved in Javascript using the dot syntax without polluting the data object or prototype with a function.

See Also

• @kingjs/enumerable.define
• @kingjs/make-enumerable
• @kingjs/define-generator

Acknowledgments

Like LINQ.

License

MIT