forked from swiftwasm/JavaScriptKit
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathJSArray.swift
More file actions
104 lines (88 loc) · 3.1 KB
/
JSArray.swift
File metadata and controls
104 lines (88 loc) · 3.1 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
/// A wrapper around [the JavaScript `Array`
/// class](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)
/// that exposes its properties in a type-safe and Swifty way.
public class JSArray: JSBridgedClass {
public static let constructor = JSObject.global.Array.function
static func isArray(_ object: JSObject) -> Bool {
constructor!.isArray!(object).boolean!
}
public let jsObject: JSObject
public required convenience init?(from value: JSValue) {
guard let object = value.object else { return nil }
self.init(object)
}
/// Construct a `JSArray` from Array `JSObject`.
/// Return `nil` if the object is not an Array.
///
/// - Parameter object: A `JSObject` expected to be a JavaScript Array
public convenience init?(_ jsObject: JSObject) {
guard Self.isArray(jsObject) else { return nil }
self.init(unsafelyWrapping: jsObject)
}
public required init(unsafelyWrapping jsObject: JSObject) {
self.jsObject = jsObject
}
}
extension JSArray: RandomAccessCollection {
public typealias Element = JSValue
public func makeIterator() -> Iterator {
Iterator(jsObject: jsObject)
}
/// Iterator type for `JSArray`, conforming to `IteratorProtocol` from the standard library, which allows
/// easy iteration over elements of `JSArray` instances.
public class Iterator: IteratorProtocol {
private let jsObject: JSObject
private var index = 0
init(jsObject: JSObject) {
self.jsObject = jsObject
}
public func next() -> Element? {
let currentIndex = index
guard currentIndex < Int(jsObject.length.number!) else {
return nil
}
index += 1
guard jsObject.hasOwnProperty!(currentIndex).boolean! else {
return next()
}
let value = jsObject[currentIndex]
return value
}
}
public subscript(position: Int) -> JSValue {
jsObject[position]
}
public var startIndex: Int { 0 }
public var endIndex: Int { length }
/// The number of elements in that array including empty hole.
/// Note that `length` respects JavaScript's `Array.prototype.length`
///
/// e.g.
/// ```javascript
/// const array = [1, , 3];
/// ```
/// ```swift
/// let array: JSArray = ...
/// array.length // 3
/// array.count // 2
/// ```
public var length: Int {
Int(jsObject.length.number!)
}
/// The number of elements in that array **not** including empty hole.
/// Note that `count` syncs with the number that `Iterator` can iterate.
/// See also: `JSArray.length`
public var count: Int {
getObjectValuesLength(jsObject)
}
}
private let alwaysTrue = JSClosure { _ in .boolean(true) }
private func getObjectValuesLength(_ object: JSObject) -> Int {
let values = object.filter!(alwaysTrue).object!
return Int(values.length.number!)
}
public extension JSValue {
var array: JSArray? {
object.flatMap(JSArray.init)
}
}