I ran into a stranger problem in my iOS swift 3 project.
Scenarios:
I have a list of os objects that have a property, as you can see below:
var total: Double { var sum = 0.0 for item in self.products! { sum += item.price ?? 0 } return sum }
In the same class, there is another property called distance:
var distance: Double?
My compilation of projects works fine when I find the maximum distance value, for example:
let minDistance = est?.max(by: { (e1, e2) -> Bool in return e1.distance! < e2.distance! })
However, when I try to find the maximum prive value, my project compilations become too slow and consume a lot of memory in fast and sourcekitservice processes (over 40 GB).
let maxValue = est?.max(by: { (e1, e2) -> Bool in return e1.total < e2.total })
When I use the if if let block, it works fine:
if let e = est { let minDistance = e.max(by: { (e1, e2) -> Bool in return e1.distance! < e2.distance! }) let maxValue = est?.max(by: { (e1, e2) -> Bool in return e1.total < e2.total }) }
The problem in this case is when I use minDistance objects! and maxValue. If I do not use these variables, the problem does not occur.
SourceKitService memory allocation: 
Has anyone already encountered a similar problem?