native: pass argument specs in order to support varadic ffi

evaluator/src/main/kotlin/gay/pizza/pork/evaluator/FunctionContext.kt

@@ -9,7 +9,7 @@ class FunctionContext(val compilationUnitContext: CompilationUnitContext, val no
     val native = node.native!!
     val nativeFunctionProvider =
       compilationUnitContext.evaluator.nativeFunctionProvider(native.form.id)
-    nativeFunctionProvider.provideNativeFunction(native.definition.text)
+    nativeFunctionProvider.provideNativeFunction(native.definition.text, node.arguments)
   }
 
   private val nativeCached by lazy { resolveMaybeNative() }

evaluator/src/main/kotlin/gay/pizza/pork/evaluator/InternalNativeProvider.kt

@@ -1,12 +1,14 @@
 package gay.pizza.pork.evaluator
 
+import gay.pizza.pork.ast.ArgumentSpec
+
 class InternalNativeProvider(val quiet: Boolean = false) : NativeProvider {
   private val functions = mutableMapOf(
     "print" to CallableFunction(::printValues),
     "println" to CallableFunction(::printLine)
   )
 
-  override fun provideNativeFunction(definition: String): CallableFunction {
+  override fun provideNativeFunction(definition: String, arguments: List<ArgumentSpec>): CallableFunction {
     return functions[definition] ?: throw RuntimeException("Unknown Internal Function: $definition")
   }
 

evaluator/src/main/kotlin/gay/pizza/pork/evaluator/NativeProvider.kt

@@ -1,5 +1,7 @@
 package gay.pizza.pork.evaluator
 
+import gay.pizza.pork.ast.ArgumentSpec
+
 interface NativeProvider {
-  fun provideNativeFunction(definition: String): CallableFunction
+  fun provideNativeFunction(definition: String, arguments: List<ArgumentSpec>): CallableFunction
 }

examples/printf.pork

@@ -0,0 +1,5 @@
+import std ffi.printf
+
+export func main() {
+  printf("Hello World: %s\n", "Jolk")
+}

ffi/src/main/kotlin/gay/pizza/pork/ffi/JavaNativeProvider.kt

@@ -1,5 +1,6 @@
 package gay.pizza.pork.ffi
 
+import gay.pizza.pork.ast.ArgumentSpec
 import gay.pizza.pork.evaluator.CallableFunction
 import gay.pizza.pork.evaluator.NativeProvider
 import gay.pizza.pork.evaluator.None
@@ -9,7 +10,7 @@ import java.lang.invoke.MethodType
 class JavaNativeProvider : NativeProvider {
   private val lookup = MethodHandles.lookup()
 
-  override fun provideNativeFunction(definition: String): CallableFunction {
+  override fun provideNativeFunction(definition: String, arguments: List<ArgumentSpec>): CallableFunction {
     val functionDefinition = JavaFunctionDefinition.parse(definition)
     val javaClass = lookupClass(functionDefinition.type)
     val returnTypeClass = lookupClass(functionDefinition.returnType)
@@ -21,7 +22,7 @@ class JavaNativeProvider : NativeProvider {
       returnTypeClass,
       parameterClasses
     )
-    return CallableFunction { arguments -> handle.invokeWithArguments(arguments.values) ?: None }
+    return CallableFunction { functionArguments -> handle.invokeWithArguments(functionArguments.values) ?: None }
   }
 
   private fun lookupClass(name: String): Class<*> = when (name) {

ffi/src/main/kotlin/gay/pizza/pork/ffi/JnaNativeProvider.kt

@@ -1,19 +1,31 @@
 package gay.pizza.pork.ffi
 
 import com.sun.jna.Function
+import gay.pizza.pork.ast.ArgumentSpec
 import gay.pizza.pork.evaluator.CallableFunction
 import gay.pizza.pork.evaluator.NativeProvider
 
 class JnaNativeProvider : NativeProvider {
-  override fun provideNativeFunction(definition: String): CallableFunction {
+  override fun provideNativeFunction(definition: String, arguments: List<ArgumentSpec>): CallableFunction {
     val functionDefinition = FfiFunctionDefinition.parse(definition)
     val function = Function.getFunction(functionDefinition.library, functionDefinition.function)
-    return CallableFunction {
+    return CallableFunction { functionArgs ->
-      invoke(function, it.values.toTypedArray(), functionDefinition.returnType)
+      val ffiArgs = mutableListOf<Any?>()
+      for ((index, spec) in arguments.withIndex()) {
+        if (spec.multiple) {
+          val variableArguments = functionArgs.values
+            .subList(index, functionArgs.values.size)
+          ffiArgs.addAll(variableArguments)
+          break
+        } else {
+          ffiArgs.add(functionArgs.values[index])
+        }
+      }
+      invoke(function, ffiArgs.toTypedArray(), functionDefinition.returnType)
     }
   }
 
-  private fun invoke(function: Function, values: Array<Any>, type: String): Any = when (type) {
+  private fun invoke(function: Function, values: Array<Any?>, type: String): Any = when (type) {
     "void*" -> function.invokePointer(values)
     "int" -> function.invokeInt(values)
     "long" -> function.invokeLong(values)

stdlib/src/main/pork/ffi/printf.pork

@@ -0,0 +1,2 @@
+export func printf(format, arguments...)
+  native ffi "c:printf:int:char*,..."