Add OptionSet

feature/add-positional-and-option-set

Author: roanutil

README.md

@@ -37,7 +37,7 @@ struct MyCommand: TopLevelCommandRepresentable {
 }
 ```
 
-In addition to modeling the ability to enable/disable a feature, we need to set a value against some variable. For this, we can use `Option`.
+In addition to modeling the ability to enable/disable a feature, we need to set a value against some variable. For this, we can use `Option`. For options that can have multiple values, there is `OptionSet`.
 
 ```swift
 struct MyCommand: TopLevelCommandRepresentable {
@@ -47,6 +47,7 @@ struct MyCommand: TopLevelCommandRepresentable {
 
     @Flag var myFlag: Bool = false
     @Option var myOption: Int = 0
+    @OptionSet var myOptions: [String] = ["value1", "value2"]
 }
 ```
 
@@ -141,8 +142,6 @@ struct TestCommand: CommandRepresentable {
     @Flag var parallel: Bool = true
     @Option var numWorkers: Int = 1
     @Flag var showCodecovPath: Bool = false
-    var testProducts: [Command]
+    @OptionSet var testProducts: [String] = []
 }
-
-extension [Command]: ArgumentGroup {}
-```
+```

Sources/ArgumentEncoding/ArgumentGroup.swift

@@ -100,6 +100,8 @@ extension ArgumentGroup {
             return container
         } else if let option = value as? OptionProtocol {
             return .option(option)
+        } else if let optionSet = value as? OptionSetProtocol {
+            return .optionSet(optionSet)
         } else if let flag = value as? Flag {
             return .flag(flag)
         } else if let command = value as? Command {
@@ -122,6 +124,8 @@ extension ArgumentGroup {
             switch value {
             case let .option(option):
                 return option.arguments(key: label)
+            case let .optionSet(optionSet):
+                return optionSet.arguments(key: label)
             case let .flag(flag):
                 return flag.arguments(key: label)
             case let .command(command):
@@ -250,6 +254,7 @@ extension ArgumentGroup {
 // Represents the possible underlying argument types
 private enum Container {
     case option(any OptionProtocol)
+    case optionSet(any OptionSetProtocol)
     case flag(Flag)
     case command(Command)
     case topLevelCommandRep(any TopLevelCommandRepresentable)

Sources/ArgumentEncoding/Option.swift

@@ -37,16 +37,19 @@ public struct Option<Value>: OptionProtocol {
 
     // Different Value types will encode to arguments differently.
     // Using unwrap, this can be handled individually per type or collectively by protocol
-    private let unwrap: @Sendable (Value) -> [String]
-    internal var unwrapped: [String] {
+    private let unwrap: @Sendable (Value) -> String?
+    internal var unwrapped: String? {
         unwrap(wrappedValue)
     }
 
-    func encoding(key: String? = nil) -> [OptionEncoding] {
+    func encoding(key: String? = nil) -> OptionEncoding? {
         guard let _key = keyOverride ?? key else {
-            return []
+            return nil
         }
-        return unwrapped.map { OptionEncoding(key: _key, value: $0) }
+        guard let unwrapped else {
+            return nil
+        }
+        return OptionEncoding(key: _key, value: unwrapped)
     }
 
     /// Get the Option's argument encoding. If `keyOverRide` and `key` are both `nil`, it will return an empty array.
@@ -55,7 +58,7 @@ public struct Option<Value>: OptionProtocol {
     ///     - key: Optionally provide a key value.
     /// - Returns: The argument encoding which is an array of strings
     public func arguments(key: String? = nil) -> [String] {
-        encoding(key: key).flatMap { $0.arguments() }
+        encoding(key: key)?.arguments() ?? []
     }
 
     /// Initializes a new option when not used as a `@propertyWrapper`
@@ -64,7 +67,7 @@ public struct Option<Value>: OptionProtocol {
     ///     - key: Explicit key value
     ///     - wrappedValue: The underlying value
     ///     - unwrap: A closure for mapping a Value to [String]
-    public init(key: some CustomStringConvertible, value: Value, unwrap: @escaping @Sendable (Value) -> [String]) {
+    public init(key: some CustomStringConvertible, value: Value, unwrap: @escaping @Sendable (Value) -> String?) {
         keyOverride = key.description
         wrappedValue = value
         self.unwrap = unwrap
@@ -76,7 +79,7 @@ public struct Option<Value>: OptionProtocol {
     ///     - wrappedValue: The underlying value
     ///     - _ key: Optional explicit key value
     ///     - _ unwrap: A closure for mapping a Value to [String]
-    public init(wrappedValue: Value, _ key: String? = nil, _ unwrap: @escaping @Sendable (Value) -> [String]) {
+    public init(wrappedValue: Value, _ key: String? = nil, _ unwrap: @escaping @Sendable (Value) -> String?) {
         keyOverride = key
         self.wrappedValue = wrappedValue
         self.unwrap = unwrap
@@ -128,8 +131,8 @@ extension Option where Value: CustomStringConvertible {
     }
 
     @Sendable
-    public static func unwrap(_ value: Value) -> [String] {
-        [value.description]
+    public static func unwrap(_ value: Value) -> String? {
+        value.description
     }
 }
 
@@ -157,8 +160,8 @@ extension Option where Value: RawRepresentable, Value.RawValue: CustomStringConv
     }
 
     @Sendable
-    public static func unwrap(_ value: Value) -> [String] {
-        [value.rawValue.description]
+    public static func unwrap(_ value: Value) -> String? {
+        value.rawValue.description
     }
 }
 
@@ -188,8 +191,8 @@ extension Option where Value: CustomStringConvertible, Value: RawRepresentable,
     }
 
     @Sendable
-    public static func unwrap(_ value: Value) -> [String] {
-        [value.rawValue.description]
+    public static func unwrap(_ value: Value) -> String? {
+        value.rawValue.description
     }
 }
 
@@ -223,62 +226,25 @@ extension Option {
     }
 
     @Sendable
-    public static func unwrap<Wrapped>(_ value: Wrapped?) -> [String] where Wrapped: CustomStringConvertible,
+    public static func unwrap<Wrapped>(_ value: Wrapped?) -> String? where Wrapped: CustomStringConvertible,
         Value == Wrapped?
     {
-        [value?.description].compactMap { $0 }
-    }
-}
-
-// MARK: Convenience initializers when Value == Sequence<E>
-
-extension Option {
-    /// Initializes a new option when not used as a `@propertyWrapper`
-    ///
-    /// - Parameters
-    ///     - key: Explicit key value
-    ///     - wrappedValue: The underlying value
-    public init<E>(key: some CustomStringConvertible, values: Value) where Value: Sequence, Value.Element == E,
-        E: CustomStringConvertible
-    {
-        keyOverride = key.description
-        wrappedValue = values
-        unwrap = Self.unwrap(_:)
-    }
-
-    /// Initializes a new option when used as a `@propertyWrapper`
-    ///
-    /// - Parameters
-    ///     - wrappedValue: The underlying value
-    ///     - _ key: Optional explicit key value
-    public init<E>(wrappedValue: Value, _ key: String? = nil) where Value: Sequence, Value.Element == E,
-        E: CustomStringConvertible
-    {
-        keyOverride = key
-        self.wrappedValue = wrappedValue
-        unwrap = Self.unwrap(_:)
-    }
-
-    @Sendable
-    public static func unwrap<E>(_ value: Value) -> [String] where Value: Sequence, Value.Element == E,
-        E: CustomStringConvertible
-    {
-        value.map(\E.description)
+        value?.description
     }
 }
 
 // MARK: ExpressibleBy...Literal conformances
 
 extension Option: ExpressibleByIntegerLiteral where Value: BinaryInteger, Value.IntegerLiteralType == Int {
     public init(integerLiteral value: IntegerLiteralType) {
-        self.init(wrappedValue: Value(integerLiteral: value), nil) { [$0.description] }
+        self.init(wrappedValue: Value(integerLiteral: value), nil) { $0.description }
     }
 }
 
 #if os(macOS)
     extension Option: ExpressibleByFloatLiteral where Value: BinaryFloatingPoint {
         public init(floatLiteral value: FloatLiteralType) {
-            self.init(wrappedValue: Value(value), nil) { [$0.formatted()] }
+            self.init(wrappedValue: Value(value), nil) { $0.formatted() }
         }
     }
 #endif
@@ -307,8 +273,10 @@ extension Option: ExpressibleByStringInterpolation where Value: StringProtocol {
     }
 }
 
+// MARK: Coding
+
 extension Option: DecodableWithConfiguration where Value: Decodable {
-    public init(from decoder: Decoder, configuration: @escaping @Sendable (Value) -> [String]) throws {
+    public init(from decoder: Decoder, configuration: @escaping @Sendable (Value) -> String?) throws {
         let container = try decoder.singleValueContainer()
         try self.init(wrappedValue: container.decode(Value.self), nil, configuration)
     }