Search Algorithm. .

gistfile1.txt

I looking for in my string exact number of word/sentence for example:<br>
What i am tried:

    let str = "Art of swift, now art of swift5 but this is true art of swift from 2014 now what do you think about art of swift?"
    var search = "art of swift"
    
    str.contains(word:search)
    var count = str.lowercased().components(separatedBy: search.lowercased()).count
    print(count - 1) 
output:
  

      4

I am looking for it should be `3` because of `art of swift5` not looking for search. 

In the example above, it returns 4 because of found "art of swift" in the word "art of swift5". I want a method that will return 3 in that condition.

**But method have more few case:**<br>

**Allow**<br>
 case-insensitive for user can be upper case or lower it doesn't matter for search result counter. example user put `Art of swift` in the text string has `art of swift` 

 

     Art of swift // it will return true as found 1


any special character allow for example `? , . etc` 
  

    art of swift? // it will return true as found 1

even special character with character allow for example ` 
  

    art of swift's // it will return true as found 1

**Don't allow:**<br>
 don't allowing different language character for example
  

    art of swiftবাং // it will return false as not found 0

even it not allowing same language character <br>

    art of swiftly // it will return false as not found 0


Why need it? 

i am trying to implement search result items show it base on best match priority. 


=================================================================================================================

    import Foundation
    
    extension String {
        func nazmulCount(of needle: String) -> Int {
            let pattern = "\\b" + NSRegularExpression.escapedPattern(for: needle) + "\\b"
            let rex = try! NSRegularExpression(pattern: pattern, options: [.caseInsensitive])
            return rex.matches(in: self, options: [], range: NSRange(startIndex..., in: self)).count
        }
    }
    
    "Art of swift, now art of swift5 but this is true art of swift from 2014 now what do you think about art of swift?".nazmulCount(of: "art of swift")
    // 3
    
    "Art of swift".nazmulCount(of: "art of swift")
    // 1
    
    "art of swift?".nazmulCount(of: "art of swift")
    // 1
    
    "art of swift's".nazmulCount(of: "art of swift")
    // 1
    
    "art of swiftবাং".nazmulCount(of: "art of swift")
    // 0
    
    "art of swiftly".nazmulCount(of: "art of swift")
    // 0