CODEWITHSUNDEEP
linuxswift
skyrealman
skyrealman

Reputation: 33

How to cast between CFString and String with swift on linux

I want to cast some Latin strings to English(PinYin) with swift on Linux，so I wrote a function, but it seems to have some errors in it. It can run in xcode on mac os, but it will go wrong on Linux. I think there are something wrong in the conversion between CFString and string. I don't know what it is. Can someone help me? Thanks 

import Foundation
#if os(Linux)
import CoreFoundation
import Glibc
#endif
public extension String{
func transformToLatinStripDiacritics() -> String{
    let nsStr = NSMutableString(string: self)
    let str = unsafeBitCast(nsStr, to: CFMutableString.self)
    if CFStringTransform(str, nil, kCFStringTransformToLatin, false){
        if CFStringTransform(str, nil, kCFStringTransformStripDiacritics, false){
            let s = String(describing: unsafeBitCast(str, to: NSMutableString.self) as NSString)
            return s
        }
        return self
    }
    return self
}

}

Upvotes: 3

Views: 717

Answers (1)

OOPer
OOPer

Reputation: 47876

As far as I tried on the IBM Swift Sandbox, CFStringTransform does not work on arbitrary CFMutableStrings. Seems it requires CFMutableString based on UTF-16 representation.

import Foundation
#if os(Linux)
    import CoreFoundation
    import Glibc
#endif
public extension String {
    func transformToLatinStripDiacritics() -> String{
        let chars = Array(self.utf16)
        let cfStr = CFStringCreateWithCharacters(nil, chars, self.utf16.count)
        let str = CFStringCreateMutableCopy(nil, 0, cfStr)!
        if CFStringTransform(str, nil, kCFStringTransformToLatin, false) {
            if CFStringTransform(str, nil, kCFStringTransformStripDiacritics, false) {
                return String(describing: str)
            }
            return self
        }
        return self
    }
}

print("我在大阪住".transformToLatinStripDiacritics()) //->wo zai da ban zhu

Tested only for a few examples. So, this may not be the best solution for your issue.

Upvotes: 3

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