basis for random subsystem

Sources/Voxelotl/Random/Arc4Random.swift

@@ -0,0 +1,24 @@
+import Foundation
+
+public class Arc4Random: RandomProvider {
+  public typealias Output = UInt32
+
+  public static var min: UInt32 { 0x00000000 }
+  public static var max: UInt32 { 0xFFFFFFFF }
+
+  private init() {}
+  public static let instance = Arc4Random()
+
+  public func stir() {
+    arc4random_stir()
+  }
+
+  public func next() -> UInt32 {
+    arc4random()
+  }
+
+  public func next(in bound: Range<Int>) -> Int {
+    assert(bound.upperBound <= Self.max)
+    return bound.lowerBound + Int(arc4random_uniform(UInt32(bound.upperBound)))
+  }
+}

Sources/Voxelotl/Random/RandomProvider.swift

@@ -0,0 +1,8 @@
+public protocol RandomProvider {
+  associatedtype Output: FixedWidthInteger
+
+  static var min: Output { get }
+  static var max: Output { get }
+
+  mutating func next() -> Output
+}