STEP 2- 6

main.swift

import Foundation


enum Unit : String {
    case    cm =   "cm"
    case    m =    "m"
    case inch = "inch"
    case yard = "yard"
    
    case g  = "g"
    case kg = "kg"
    case oz = "oz"
    case lb = "lb"
    
    func defaultUnit ()->Unit{
        
        switch self {
        case .cm,.m,.inch,.yard:
            return .m
        case .g,.kg,.oz,.lb:
            return .kg
        }
    }
}
    
    
    typealias value = Double
    
    typealias UnitRatio = Double
    
    typealias beforeUnit = Unit
    
    typealias afterUnit = Unit
    
    
    func getRatio( units: (beforeUnit,afterUnit)) ->(Double){
        
        var unitRatioTable : [beforeUnit:[afterUnit:UnitRatio]] =
            [
                .m:
                    [      .cm:   100,
                           .inch:   0.393701,
                           .yard:   0.0109361
                ],
                .cm:
                    [    .m:   0.01,
                         .inch:   39.3701,
                         .yard:   1.09361
                ],
                .inch:
                    [
                        .m:    0.0254,
                        .cm:    2.54,
                        .yard:  0.0277778
                ],
                .yard:
                    [
                        .cm:    91.44,
                        .m:     0.9144,
                        .inch:  36
                ],
                .g:
                    [
                        .kg:    1000,
                        .oz:    0.035274,
                        .lb:    0.00220462
                ],
                .kg:
                    [
                        .g:     1000,
                        .oz:    35.274,
                        .lb:    2.20462
                ],
                .oz:
                    [
                        .g:     28.3495,
                        .kg:    0.0283495,
                        .lb:    0.0625
                ],
                .lb:[
                    .g:     453.592,
                    .kg:    0.453592,
                    .oz:    16
                ]
                
        ]
        let (beforeUnit,afterUnit) = units
        
        
        let ratio = beforeUnit == afterUnit ? 1 :(unitRatioTable[beforeUnit])![afterUnit]
        
        return ratio!
        
        
    }
    
    
    func convert(userInput:String)->String{
        
        let (value,units) = recognize(userInput: userInput)
        let ratio  = getRatio(units:units)
        
        return "\(calculatedValueString(value: value, ratio: ratio))\(units.1)"
        
        
    }
    
    func calculatedValueString(value:Double,ratio:Double)->String{
        
        let result = value * ratio
        
        return confirmNumber(number: result)
        
        
    }
    
    func confirmNumber(number:Double)->String{
        
        if(number.remainder(dividingBy: 1)==0){
            return "\(Int.init(number))"
        }else{
            return "\(number)"
        }
        
    }
    
    
    func recognize(userInput : String)->(value,(beforeUnit,afterUnit)){
        
        let value = getValue(userInput: userInput)
        let units = getUnits(userInput: userInput)
        
        return (value,units)
    }
    
    func getValue (userInput:String)->Double{
        let pattern = "[0-9.]+"
        let value = usingRegex(userInput: userInput, pattern: pattern)
        return Double.init(value)!
    }
    
    func getUnits(userInput:String)->(beforeUnit,afterUnit){
        let pattern = "[^0-9.]+"
        let units =  usingRegex(userInput: userInput, pattern: pattern)
        
        let unitArray = units.split(separator: " ")
        
        let beforeUnit = Unit.init(rawValue: String(unitArray[0]))
     
        let afterUnit:Unit
        if  unitArray.count == 2 {
            
            afterUnit = Unit.init(rawValue: String(unitArray[1]))!
        
        }else{
            afterUnit = beforeUnit!.defaultUnit()
        }
        
        return (beforeUnit!,afterUnit)
        
    }
    
    func usingRegex( userInput:String ,pattern:String ) -> String{
        
        let regexUnits = try! NSRegularExpression.init(pattern: pattern, options: [])
        let matchs = regexUnits.firstMatch(in: userInput, options: [], range: NSRange.init(location: 0, length: userInput.count))
        let part = NSString.init(string: userInput).substring(with: (matchs?.range)!)
        
        return part
        
    }
    
    func unitConverter(){
        
        let quitCommends = ["q","quit"]
        
        while(true){
            
            
            print("변환할 값을 입력하세요")
            let inputValue = readLine()
        
            for quitCommend in quitCommends {
                if(quitCommend == inputValue){
                    break
                    
                }
            }
            
            
            print(convert(userInput: inputValue!))
            
            
        }
}

unitConverter()

피드백 감사합니다 .