The first sequence of the join operation.
The second sequence of the join operation.
Function that projects the key given an element from first.
Function that projects the key given an element from second.
Function that projects the result given just an element from second where there is no corresponding element in first.
Function that projects the result given an element from first and an element from second that match on a common key.
OptionalequalityComparer: EqualityComparer<TKey>A function to compare keys.
A sequence containing results projected from a right outer join of the two input sequences.
const right = 'right';
const both = 'both';
const missing = null;
type Side = typeof right | typeof both;
type Person = { name: string };
type Pet = { name: string; owner: Person };
const magnus: Person = { name: 'Magnus' };
const terry: Person = { name: 'Terry' };
const adam: Person = { name: 'Adam' };
const john: Person = { name: 'John' };
const barley: Pet = { name: 'Barley', owner: terry };
const boots: Pet = { name: 'Boots', owner: terry };
const whiskers: Pet = { name: 'Whiskers', owner: adam };
const daisy: Pet = { name: 'Daisy', owner: magnus };
const scratchy: Pet = { name: 'Scratchy', owner: { name: 'Bob' } };
const people = from([magnus, terry, adam, john]);
const pets = from([barley, boots, whiskers, daisy, scratchy]);
const result = rightJoinHeterogeneous<Pet, Person, { side: Side; left: Person | null; right: Pet }>(
people,
pets,
person => person,
pet => pet.owner,
pet => ({ side: right, left: missing, right: pet }),
(person, pet) => ({ side: both, left: person, right: pet })
)
.toArray();
expect(result).toEqual([
{ side: both, left: terry, right: barley },
{ side: both, left: terry, right: boots },
{ side: both, left: adam, right: whiskers },
{ side: both, left: magnus, right: daisy },
{ side: right, left: missing, right: scratchy } // Scratchy has an owner, Bob, but Bob is not in the calling collection, hence the 'missing'.
]);
Performs a right outer join on two heterogeneous sequences.