Function groupJoin

Correlates the elements of two sequences based on key equality, and groups the results.

Example

const magnus = { name: 'Magnus' };
const terry = { name: 'Terry' };
const adam = { name: 'Adam' };
const john = { name: 'John' };

const barley = { name: 'Barley', owner: terry };
const boots = { name: 'Boots', owner: terry };
const whiskers = { name: 'Whiskers', owner: adam };
const daisy = { name: 'Daisy', owner: magnus };
const scratchy = { name: 'Scratchy', owner: { name: 'Bob' } };

const people = from([magnus, terry, adam, john]);
const pets = from([barley, boots, whiskers, daisy, scratchy]);

const result = groupJoin(
    people,
    pets,
    person => person,
    pet => pet.owner,
    (person, petCollection) => ({ ownerName: person.name, pets: petCollection.select(p => p.name).toArray() })
  )
  .toArray();

expect(result).toEqual([
  { ownerName: 'Magnus', pets: ['Daisy'] },
  { ownerName: 'Terry', pets: ['Barley', 'Boots'] },
  { ownerName: 'Adam', pets: ['Whiskers'] },
  { ownerName: 'John', pets: [] }
]);

Typeparam

TOuter The type of the elements of the first sequence.

Typeparam

TInner The type of the elements of the second sequence.

Typeparam

TKey The type of the keys returned by the key selector functions.

Typeparam

TResult The type of the result elements.