Dictionary

Creates a new dictionary whose keys are the groupings returned by the given closure and whose values are arrays of the elements that returned each key.

// [Int64: [Player]]
let cursor = try Player.fetchCursor(db)
let dictionary = try Dictionary(grouping: cursor, by: { $0.teamID })

Creates a new dictionary whose keys are the groupings returned by the given closure and whose values are arrays of the elements that returned each key.

// [Int64: [Player]]
let cursor = try Player.fetchCursor(db)
let dictionary = try Dictionary(
    minimumCapacity: 100,
    grouping: cursor,
    by: { $0.teamID })

Creates a new dictionary from the key-value pairs in the given cursor.

You use this initializer to create a dictionary when you have a cursor of key-value tuples with unique keys. Passing a cursor with duplicate keys to this initializer results in a fatal error.

// [Int64: Player]
let cursor = try Player.fetchCursor(db).map { ($0.id, $0) }
let playerByID = try Dictionary(uniqueKeysWithValues: cursor)

Creates a new dictionary from the key-value pairs in the given cursor.

You use this initializer to create a dictionary when you have a cursor of key-value tuples with unique keys. Passing a cursor with duplicate keys to this initializer results in a fatal error.

// [Int64: Player]
let cursor = try Player.fetchCursor(db).map { ($0.id, $0) }
let playerByID = try Dictionary(
    minimumCapacity: 100,
    uniqueKeysWithValues: cursor)