Scala Native¶

Scala Native is an optimizing ahead-of-time compiler and lightweight managed runtime designed specifically for Scala. It features:

• Low-level primitives.

  import scala.scalanative.unsafe._
  
  type Vec = CStruct3[Double, Double, Double]
  
  def sum(vec: Ptr[Vec]): Double =
    return vec._1 + vec._2 + vec._3
  
  @main def main(): Unit =
    val vec = stackalloc[Vec]() // allocate c struct on stack
    vec._1 = 10.0             // initialize fields
    vec._2 = 20.0
    vec._3 = 30.0
    println(sum(vec))         // pass by reference
  

  Pointers, structs, you name it. Low-level primitives let you hand-tune your application to make it work exactly as you want it to. You’re in control.

• Seamless interop with native code.

  import scala.scalanative.unsafe._
  import scala.scalanative.unsigned._
  
  @extern object stdlib {
    def malloc(size: CSize): Ptr[Byte] = extern
  }
  
  val ptr = stdlib.malloc(32.toCSize)
  

  Calling C code has never been easier. With the help of extern objects you can seamlessly call native code without any runtime overhead.

• Instant startup time.

  > time hello-native
  hello, native!
  
  real    0m0.005s
  user    0m0.002s
  sys     0m0.002s
  

  Scala Native is compiled ahead-of-time via LLVM. This means that there is no sluggish warm-up phase that’s common for just-in-time compilers. Your code is immediately fast and ready for action.