// DictionaryExtensions.swift - Copyright 2024 SwifterSwift
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#if canImport(Foundation)
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import Foundation
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#endif
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// MARK: - Methods
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public extension Dictionary {
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/// SwifterSwift: Creates a Dictionary from a given sequence grouped by a given key path.
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///
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/// - Parameters:
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/// - sequence: Sequence being grouped.
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/// - keypath: The key path to group by.
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init<S: Sequence>(grouping sequence: S, by keyPath: KeyPath<S.Element, Key>) where Value == [S.Element] {
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self.init(grouping: sequence, by: { $0[keyPath: keyPath] })
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}
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/// SwifterSwift: Check if key exists in dictionary.
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///
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/// let dict: [String: Any] = ["testKey": "testValue", "testArrayKey": [1, 2, 3, 4, 5]]
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/// dict.has(key: "testKey") -> true
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/// dict.has(key: "anotherKey") -> false
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///
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/// - Parameter key: key to search for.
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/// - Returns: true if key exists in dictionary.
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func has(key: Key) -> Bool {
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return index(forKey: key) != nil
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}
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/// SwifterSwift: Remove all keys contained in the keys parameter from the dictionary.
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///
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/// var dict : [String: String] = ["key1" : "value1", "key2" : "value2", "key3" : "value3"]
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/// dict.removeAll(keys: ["key1", "key2"])
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/// dict.keys.contains("key3") -> true
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/// dict.keys.contains("key1") -> false
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/// dict.keys.contains("key2") -> false
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///
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/// - Parameter keys: keys to be removed.
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mutating func removeAll(keys: some Sequence<Key>) {
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keys.forEach { removeValue(forKey: $0) }
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}
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/// SwifterSwift: Remove a value for a random key from the dictionary.
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@discardableResult
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mutating func removeValueForRandomKey() -> Value? {
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guard let randomKey = keys.randomElement() else { return nil }
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return removeValue(forKey: randomKey)
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}
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#if canImport(Foundation)
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/// SwifterSwift: JSON Data from dictionary.
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///
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/// - Parameter prettify: set true to prettify data (default is false).
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/// - Returns: optional JSON Data (if applicable).
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func jsonData(prettify: Bool = false) -> Data? {
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guard JSONSerialization.isValidJSONObject(self) else {
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return nil
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}
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let options = (prettify == true) ? JSONSerialization.WritingOptions.prettyPrinted : JSONSerialization
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.WritingOptions()
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return try? JSONSerialization.data(withJSONObject: self, options: options)
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}
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#endif
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#if canImport(Foundation)
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/// SwifterSwift: JSON String from dictionary.
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///
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/// dict.jsonString() -> "{"testKey":"testValue","testArrayKey":[1,2,3,4,5]}"
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///
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/// dict.jsonString(prettify: true)
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/// /*
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/// returns the following string:
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///
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/// "{
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/// "testKey" : "testValue",
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/// "testArrayKey" : [
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/// 1,
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/// 2,
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/// 3,
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/// 4,
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/// 5
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/// ]
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/// }"
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///
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/// */
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///
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/// - Parameter prettify: set true to prettify string (default is false).
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/// - Returns: optional JSON String (if applicable).
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func jsonString(prettify: Bool = false) -> String? {
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guard JSONSerialization.isValidJSONObject(self) else { return nil }
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let options = (prettify == true) ? JSONSerialization.WritingOptions.prettyPrinted : JSONSerialization
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.WritingOptions()
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guard let jsonData = try? JSONSerialization.data(withJSONObject: self, options: options) else { return nil }
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return String(data: jsonData, encoding: .utf8)
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}
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#endif
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/// SwifterSwift: Returns a dictionary containing the results of mapping the given closure over the sequence’s
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/// elements.
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/// - Parameter transform: A mapping closure. `transform` accepts an element of this sequence as its parameter and
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/// returns a transformed value of the same or of a different type.
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/// - Returns: A dictionary containing the transformed elements of this sequence.
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func mapKeysAndValues<K, V>(_ transform: ((key: Key, value: Value)) throws -> (K, V)) rethrows -> [K: V] {
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return try [K: V](uniqueKeysWithValues: map(transform))
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}
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/// SwifterSwift: Returns a dictionary containing the non-`nil` results of calling the given transformation with
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/// each element of this sequence.
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/// - Parameter transform: A closure that accepts an element of this sequence as its argument and returns an
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/// optional value.
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/// - Returns: A dictionary of the non-`nil` results of calling `transform` with each element of the sequence.
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/// - Complexity: *O(m + n)*, where _m_ is the length of this sequence and _n_ is the length of the result.
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func compactMapKeysAndValues<K, V>(_ transform: ((key: Key, value: Value)) throws -> (K, V)?) rethrows -> [K: V] {
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return try [K: V](uniqueKeysWithValues: compactMap(transform))
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}
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/// SwifterSwift: Creates a new dictionary using specified keys.
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///
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/// var dict = ["key1": 1, "key2": 2, "key3": 3, "key4": 4]
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/// dict.pick(keys: ["key1", "key3", "key4"]) -> ["key1": 1, "key3": 3, "key4": 4]
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/// dict.pick(keys: ["key2"]) -> ["key2": 2]
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///
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/// - Complexity: O(K), where _K_ is the length of the keys array.
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///
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/// - Parameter keys: An array of keys that will be the entries in the resulting dictionary.
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///
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/// - Returns: A new dictionary that contains the specified keys only. If none of the keys exist, an empty
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/// dictionary will be returned.
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func pick(keys: [Key]) -> [Key: Value] {
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keys.reduce(into: [Key: Value]()) { result, item in
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result[item] = self[item]
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}
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}
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}
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// MARK: - Methods (Value: Equatable)
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public extension Dictionary where Value: Equatable {
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/// SwifterSwift: Returns an array of all keys that have the given value in dictionary.
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///
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/// let dict = ["key1": "value1", "key2": "value1", "key3": "value2"]
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/// dict.keys(forValue: "value1") -> ["key1", "key2"]
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/// dict.keys(forValue: "value2") -> ["key3"]
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/// dict.keys(forValue: "value3") -> []
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///
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/// - Parameter value: Value for which keys are to be fetched.
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/// - Returns: An array containing keys that have the given value.
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func keys(forValue value: Value) -> [Key] {
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return keys.filter { self[$0] == value }
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}
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}
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// MARK: - Methods (ExpressibleByStringLiteral)
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public extension Dictionary where Key: StringProtocol {
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/// SwifterSwift: Lowercase all keys in dictionary.
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///
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/// var dict = ["tEstKeY": "value"]
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/// dict.lowercaseAllKeys()
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/// print(dict) // prints "["testkey": "value"]"
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///
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mutating func lowercaseAllKeys() {
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// http://stackoverflow.com/questions/33180028/extend-dictionary-where-key-is-of-type-string
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for key in keys {
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if let lowercaseKey = String(describing: key).lowercased() as? Key {
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self[lowercaseKey] = removeValue(forKey: key)
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}
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}
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}
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}
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// MARK: - Subscripts
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public extension Dictionary {
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/// SwifterSwift: Deep fetch or set a value from nested dictionaries.
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///
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/// var dict = ["key": ["key1": ["key2": "value"]]]
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/// dict[path: ["key", "key1", "key2"]] = "newValue"
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/// dict[path: ["key", "key1", "key2"]] -> "newValue"
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///
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/// - Note: Value fetching is iterative, while setting is recursive.
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///
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/// - Complexity: O(N), _N_ being the length of the path passed in.
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///
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/// - Parameter path: An array of keys to the desired value.
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///
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/// - Returns: The value for the key-path passed in. `nil` if no value is found.
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subscript(path path: [Key]) -> Any? {
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get {
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guard !path.isEmpty else { return nil }
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var result: Any? = self
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for key in path {
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if let element = (result as? [Key: Any])?[key] {
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result = element
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} else {
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return nil
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}
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}
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return result
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}
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set {
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if let first = path.first {
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if path.count == 1, let new = newValue as? Value {
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return self[first] = new
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}
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if var nested = self[first] as? [Key: Any] {
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nested[path: Array(path.dropFirst())] = newValue
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return self[first] = nested as? Value
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}
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}
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}
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}
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}
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// MARK: - Operators
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public extension Dictionary {
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/// SwifterSwift: Merge the keys/values of two dictionaries.
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///
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/// let dict: [String: String] = ["key1": "value1"]
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/// let dict2: [String: String] = ["key2": "value2"]
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/// let result = dict + dict2
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/// result["key1"] -> "value1"
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/// result["key2"] -> "value2"
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///
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/// - Parameters:
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/// - lhs: dictionary.
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/// - rhs: dictionary.
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/// - Returns: An dictionary with keys and values from both.
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static func + (lhs: [Key: Value], rhs: [Key: Value]) -> [Key: Value] {
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var result = lhs
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rhs.forEach { result[$0] = $1 }
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return result
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}
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// MARK: - Operators
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/// SwifterSwift: Append the keys and values from the second dictionary into the first one.
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///
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/// var dict: [String: String] = ["key1": "value1"]
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/// let dict2: [String: String] = ["key2": "value2"]
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/// dict += dict2
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/// dict["key1"] -> "value1"
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/// dict["key2"] -> "value2"
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///
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/// - Parameters:
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/// - lhs: dictionary.
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/// - rhs: dictionary.
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static func += (lhs: inout [Key: Value], rhs: [Key: Value]) {
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rhs.forEach { lhs[$0] = $1 }
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}
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/// SwifterSwift: Remove keys contained in the sequence from the dictionary.
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///
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/// let dict: [String: String] = ["key1": "value1", "key2": "value2", "key3": "value3"]
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/// let result = dict-["key1", "key2"]
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/// result.keys.contains("key3") -> true
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/// result.keys.contains("key1") -> false
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/// result.keys.contains("key2") -> false
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///
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/// - Parameters:
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/// - lhs: dictionary.
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/// - keys: array with the keys to be removed.
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/// - Returns: a new dictionary with keys removed.
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static func - (lhs: [Key: Value], keys: some Sequence<Key>) -> [Key: Value] {
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var result = lhs
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result.removeAll(keys: keys)
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return result
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}
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/// SwifterSwift: Remove keys contained in the sequence from the dictionary.
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///
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/// var dict: [String: String] = ["key1": "value1", "key2": "value2", "key3": "value3"]
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/// dict-=["key1", "key2"]
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/// dict.keys.contains("key3") -> true
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/// dict.keys.contains("key1") -> false
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/// dict.keys.contains("key2") -> false
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///
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/// - Parameters:
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/// - lhs: dictionary.
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/// - keys: array with the keys to be removed.
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static func -= (lhs: inout [Key: Value], keys: some Sequence<Key>) {
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lhs.removeAll(keys: keys)
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}
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}
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