CODEWITHSUNDEEP
swiftgenerics
highboi
highboi

Reputation: 683

How can i use an enum value in a generic class

Im writing a logging class to use in my projects based on Log.

In Log, the logging methods are called like so

open func trace(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(.trace, items, separator, terminator, file, line, column, function)
}

open func debug(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(.debug, items, separator, terminator, file, line, column, function)
}

open func info(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(.info, items, separator, terminator, file, line, column, function)
}

open func warning(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(.warning, items, separator, terminator, file, line, column, function)
}

open func error(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(.error, items, separator, terminator, file, line, column, function)
}

These all work fine, but i find the code to be too repetitive and would like to replace it with a single method using a Generic T type

open func log<T: Level>(_ items: Any..., separator: String = " ", terminator: String = "\n", file: String = #file, line: Int = #line, column: Int = #column, function: String = #function) {
    log(T, items, separator, terminator, file, line, column, function)
}

The method I've come up with is

class public func log<T: LogLevelGeneric>(_ items: Any..., separator: String = "", _ file: String = #file, _ line: Int = #line, _ function: String = #function, t:T) {
         // Error: Inheritance from non-protocol, non-class type LogLevelGeneric

}


public enum LogLevelGeneric: String {
    case pretty  = "💖Prettify"
    case measure = "🖤Measure "
    case verbose = "💚Verbose "
    case info    = "💙Info    "
    case warning = "💛Warning "
    case debug   = "💜Debug   "
    case error   = "❤️️Error   "
}

Searching google and stackoverflow, ive found that what im trying to do can be achieved and it can't, and so far i've only proved it cant be done.

Could someone point me in the right direction of how this can be done? Thanks.

Upvotes: 0

Views: 83

Answers (1)

vadian
vadian

Reputation: 285072

The error message says you can't use an enum as a generic constraint.

Actually you don't need a generic function, pass the level as a parameter for example

class public func log(level: LogLevelGeneric, items: Any..., separator: String = "", _ file: String = #file, _ line: Int = #line, _ function: String = #function) {


}

Upvotes: 3

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