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// StringRemoveDupes benchmark
//
// Source: https://gist.github.com/airspeedswift/83eee31e1d9e52fd5570
import TestsUtils
public let benchmarks =
BenchmarkInfo(
name: "StringRemoveDupes",
runFunction: run_StringRemoveDupes,
tags: [.validation, .String]
)
@inline(never)
public func run_StringRemoveDupes(_ n: Int) {
let textLengthRef = 25
let text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. " +
"Morbi nisi metus, accumsan eu sagittis et, condimentum ut " +
"arcu. Morbi aliquet porta velit, accumsan aliquam ante " +
"facilisis non. Maecenas lobortis erat vel elit fringilla " +
"blandit. Praesent euismod mauris sodales velit facilisis " +
"blandit. Morbi leo neque, finibus ut mi in, auctor sagittis."
var s = ""
for _ in 1...10*n {
s = text.removeDuplicates()
if s.count != textLengthRef {
break
}
}
check(s.count == textLengthRef)
}
// removes all but first occurrence from a sequence, returning an array.
// requires elements to be hashable, not just equatable, but the alternative
// of using contains is very inefficient
// alternatively, could require comparable, sort, and remove adjacent dupes
func uniq<S: Sequence,
E: Hashable>(_ seq: S) -> [E] where E == S.Element {
var seen: [S.Element:Int] = [:]
return seq.filter { seen.updateValue(1, forKey: $0) == nil }
}
// removeDuplicates returns a version of the String with
// all duplicates removed
extension String {
func removeDuplicates() -> String {
return String(uniq(self))
}
}
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