Swift playground 字典太慢

Question

我在 Xcode 7.1 中使用以下代码创建了一个 Swift 游乐场，其评估速度非常慢（通常需要几分钟）。为什么会这样？由于它使 playground 基本上无法使用，我可以做些什么来缩短它的执行时间吗？

let sets = [
    "TEMPERATURE":[
        (value:37.0, attributes:["A":0.0, "B":0.2]),
        (value:37.5, attributes:["A":0.0, "B":1.0]),
        (value:38.0, attributes:["A":0.2, "B":0.5]),
        (value:38.5, attributes:["A":0.5, "B":0.2]),
        (value:39.0, attributes:["A":0.8, "B":0.0]),
        (value:39.5, attributes:["A":1.0, "B":0.0]),
        (value:40.0, attributes:["A":1.0, "B":0.0]),
    ],
    "VARIATION":[
        (value:0.0, attributes:["A":0.0, "B":1.0]),
        (value:2.0, attributes:["A":0.2, "B":0.8]),
        (value:5.0, attributes:["A":0.5, "B":0.5]),
        (value:8.0, attributes:["A":0.8, "B":0.2]),
        (value:10.0, attributes:["A":1.0, "B":0.0]),
    ]
]

Answer 1

尝试在 sets 初始化后附加 "VARIATION"。如果这仍然很慢，请继续缩小范围以将越来越小的位附加到较大的字典中。我知道这很乏味，但不幸的是，这可能是 Xcode 和大量数据的常见错误。

Answer 2

这里的问题是 Swift 编译器在推断 sets 的类型时非常慢。如果将类型显式化，Swift 编译器将不必花任何时间推导它。试试这个：

let sets: [String:[(value: Double, attributes:[String:Double])]] = [
    "TEMPERATURE":[
        (value:37.0, attributes:["A":0.0, "B":0.2]),
        (value:37.5, attributes:["A":0.0, "B":1.0]),
        (value:38.0, attributes:["A":0.2, "B":0.5]),
        (value:38.5, attributes:["A":0.5, "B":0.2]),
        (value:39.0, attributes:["A":0.8, "B":0.0]),
        (value:39.5, attributes:["A":1.0, "B":0.0]),
        (value:40.0, attributes:["A":1.0, "B":0.0]),
    ],
    "VARIATION":[
        (value:0.0, attributes:["A":0.0, "B":1.0]),
        (value:2.0, attributes:["A":0.2, "B":0.8]),
        (value:5.0, attributes:["A":0.5, "B":0.5]),
        (value:8.0, attributes:["A":0.8, "B":0.2]),
        (value:10.0, attributes:["A":1.0, "B":0.0]),
    ]
]

Swift playground 字典太慢

Swift playground with dictionary too slow

swift

swift-playground