Parameter packs for zip functions

Sources/Gen/Gen.swift

@@ -53,19 +53,6 @@ extension Gen {
   }
 }
 
-/// Combines two generators into a single one.
-///
-/// - Parameters:
-///   - a: A generator of `A`s.
-///   - b: A generator of `B`s.
-/// - Returns: A generator of `(A, B)` pairs.
-@inlinable
-public func zip<A, B>(_ a: Gen<A>, _ b: Gen<B>) -> Gen<(A, B)> {
-  return Gen<(A, B)> { rng in
-    (a._run(&rng), b._run(&rng))
-  }
-}
-
 extension Gen {
   /// Transforms a generator of `Value`s into a generator of `NewValue`s by transforming a value into a generator of `NewValue`s.
   ///

Sources/Gen/UIKit.swift

@@ -3,6 +3,6 @@
 
   extension Gen where Value == UIColor {
     public static let color = zip(.float(in: 0...1), .float(in: 0...1), .float(in: 0...1))
-      .map { UIColor(red: $0, green: $1, blue: $2, alpha: 1) }
+      .map { (rgb: (Double, Double, Double)) in UIColor(red: rgb.0, green: rgb.1, blue: rgb.2, alpha: 1) }
   }
 #endif

Sources/Gen/Xoshiro.swift

@@ -6,10 +6,10 @@ public struct Xoshiro: RandomNumberGenerator {
   @inlinable
   public init() {
     self.state = zip(
-      .int(in: .min ... .max),
-      .int(in: .min ... .max),
-      .int(in: .min ... .max),
-      .int(in: .min ... .max)
+      Gen<UInt64>.int(in: .min ... .max),
+      Gen<UInt64>.int(in: .min ... .max),
+      Gen<UInt64>.int(in: .min ... .max),
+      Gen<UInt64>.int(in: .min ... .max)
     )
     .run()
   }

Sources/Gen/Zip.swift

@@ -1,3 +1,28 @@
+#if swift(>=5.9)
+/// Combines multiple generators into a single one that produces a tuple containing values from each input generator.
+///
+/// - Parameter gens: A variadic sequence of generators, each producing a value of a distinct type.
+/// - Returns: A generator that produces a tuple of values generated by each input generator in the order they were provided.
+@inlinable
+public func zip<each Value>(_ gens: repeat Gen<each Value>) -> Gen<(repeat each Value)> {
+  return Gen<(repeat each Value)> { rng in
+    return (repeat (each gens)._run(&rng))
+  }
+}
+#else
+/// Combines two generators into a single one.
+///
+/// - Parameters:
+///   - a: A generator of `A`s.
+///   - b: A generator of `B`s.
+/// - Returns: A generator of `(A, B)` pairs.
+@inlinable
+public func zip<A, B>(_ a: Gen<A>, _ b: Gen<B>) -> Gen<(A, B)> {
+  return Gen<(A, B)> { rng in
+    (a._run(&rng), b._run(&rng))
+  }
+}
+
 @inlinable
 public func zip<A, B, C>(
   _ a: Gen<A>,
@@ -113,3 +138,4 @@ public func zip<A, B, C, D, E, F, G, H, I, J>(
 {
   return zip(zip(a, b), c, d, e, f, g, h, i, j).map { ($0.0, $0.1, $1, $2, $3, $4, $5, $6, $7, $8) }
 }
+#endif