global: a working virtual machine for some of the use cases. APIs and validation still WIP.

bytecode/src/main/kotlin/gay/pizza/pork/bytecode/Constant.kt

@@ -4,6 +4,13 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 data class Constant(val id: UInt, val tag: ConstantTag, val value: ByteArray) {
+  fun readAsString(): String {
+    if (tag != ConstantTag.String) {
+      throw RuntimeException("Constant $id is not tagged as a string")
+    }
+    return String(value)
+  }
+
   override fun equals(other: Any?): Boolean {
     if (this === other) return true
     other as Constant

bytecode/src/main/kotlin/gay/pizza/pork/bytecode/ConstantPool.kt

@@ -3,4 +3,6 @@ package gay.pizza.pork.bytecode
 import kotlinx.serialization.Serializable
 
 @Serializable
-data class ConstantPool(val constants: List<Constant>)
+data class ConstantPool(val constants: List<Constant>) {
+  fun read(index: UInt): Constant = constants[index.toInt()]
+}

compiler/src/main/kotlin/gay/pizza/pork/compiler/CompilableSlab.kt

@@ -13,4 +13,9 @@ class CompilableSlab(val compiler: Compiler, val slab: Slab) {
   fun resolve(symbol: Symbol): CompilableSymbol? = compilableSymbols.firstOrNull {
     it.scopeSymbol.symbol == symbol
   }
+
+  fun resolveVisible(symbol: Symbol): CompilableSymbol? {
+    val scopeSymbol = slab.scope.resolve(symbol) ?: return null
+    return compiler.resolveOrNull(scopeSymbol)
+  }
 }

compiler/src/main/kotlin/gay/pizza/pork/compiler/LocalState.kt

@@ -53,7 +53,7 @@ class LocalState(val symbol: CompilableSymbol) {
         return Loadable(stubVar = found)
       }
     }
-    val found = this.symbol.compilableSlab.resolve(symbol)
+    val found = this.symbol.compilableSlab.resolveVisible(symbol)
     if (found != null) {
       return Loadable(call = found)
     }

compiler/src/main/kotlin/gay/pizza/pork/compiler/StubOpEmitter.kt

@@ -285,7 +285,9 @@ class StubOpEmitter(val compiler: Compiler, val symbol: CompilableSymbol) : Func
       code.emit(Opcode.Constant, listOf(defConstant))
     }
     val formConstant = compiler.constantPool.assign(ConstantTag.String, node.form.id.toByteArray())
-    code.emit(Opcode.Native, listOf(formConstant, node.definitions.size.toUInt()))
+    val functionDefinition = symbol.scopeSymbol.definition as FunctionDefinition
+    val functionArgumentCount = functionDefinition.arguments.size
+    code.emit(Opcode.Native, listOf(formConstant, node.definitions.size.toUInt(), functionArgumentCount.toUInt()))
   }
 
   private fun load(callOrStubVar: Loadable) {

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

@@ -0,0 +1,15 @@
+package gay.pizza.pork.evaluator
+
+import gay.pizza.pork.ast.gen.ArgumentSpec
+import gay.pizza.pork.execution.NativeProvider
+
+class AdaptedNativeProvider(val provider: NativeProvider) : ExpandedNativeProvider {
+  override fun provideNativeFunction(
+    definitions: List<String>,
+    arguments: List<ArgumentSpec>,
+    inside: SlabContext
+  ): CallableFunction {
+    val function = provider.provideNativeFunction(definitions)
+    return CallableFunction { args, _ -> function.invoke(args) }
+  }
+}

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

@@ -1,3 +0,0 @@
-package gay.pizza.pork.evaluator
-
-typealias ArgumentList = List<Any>

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

@@ -1,5 +1,7 @@
 package gay.pizza.pork.evaluator
 
+import gay.pizza.pork.execution.ArgumentList
+
 fun interface CallableFunction {
   fun call(arguments: ArgumentList, stack: CallStack): Any
 }

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

@@ -2,6 +2,7 @@ package gay.pizza.pork.evaluator
 
 import gay.pizza.pork.ast.FunctionLevelVisitor
 import gay.pizza.pork.ast.gen.*
+import gay.pizza.pork.execution.None
 import kotlin.math.abs
 
 @Suppress("JavaIoSerializableObjectMustHaveReadResolve")

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

@@ -1,24 +1,21 @@
 package gay.pizza.pork.evaluator
 
-import gay.pizza.pork.ast.gen.Symbol
-import gay.pizza.pork.execution.ExecutionContext
-import gay.pizza.pork.execution.ExecutionContextProvider
 import gay.pizza.pork.frontend.ImportLocator
 import gay.pizza.pork.frontend.Slab
 import gay.pizza.pork.frontend.World
 
-class Evaluator(val world: World) : ExecutionContextProvider {
+class Evaluator(val world: World) {
   private val scope = Scope.root()
   private val contexts = mutableMapOf<Slab, SlabContext>()
-  private val nativeProviders = mutableMapOf<String, NativeProvider>()
+  private val nativeProviders = mutableMapOf<String, ExpandedNativeProvider>()
 
   fun evaluate(locator: ImportLocator): Scope {
-    val slabContext = context(locator)
+    val slabContext = slabContext(locator)
     slabContext.finalizeScope()
     return slabContext.externalScope
   }
 
-  fun context(slab: Slab): SlabContext {
+  fun slabContext(slab: Slab): SlabContext {
     val slabContext = contexts.computeIfAbsent(slab) {
       SlabContext(slab, this, scope)
     }
@@ -26,20 +23,14 @@ class Evaluator(val world: World) : ExecutionContextProvider {
     return slabContext
   }
 
-  fun context(locator: ImportLocator): SlabContext = context(world.load(locator))
+  fun slabContext(locator: ImportLocator): SlabContext = slabContext(world.load(locator))
 
-  fun nativeFunctionProvider(form: String): NativeProvider {
+  fun nativeFunctionProvider(form: String): ExpandedNativeProvider {
     return nativeProviders[form] ?:
       throw RuntimeException("Unknown native function form: $form")
   }
 
-  fun addNativeProvider(form: String, nativeProvider: NativeProvider) {
+  fun addNativeProvider(form: String, nativeProvider: ExpandedNativeProvider) {
     nativeProviders[form] = nativeProvider
   }
-
-  override fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol): ExecutionContext {
-    val slab = context(importLocator)
-    slab.finalizeScope()
-    return EvaluatorExecutionContext(this, slab, entryPointSymbol)
-  }
 }

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

@@ -0,0 +1,20 @@
+package gay.pizza.pork.evaluator
+
+import gay.pizza.pork.ast.gen.Symbol
+import gay.pizza.pork.execution.ExecutionContext
+import gay.pizza.pork.execution.ExecutionContextProvider
+import gay.pizza.pork.execution.NativeRegistry
+import gay.pizza.pork.frontend.ImportLocator
+import gay.pizza.pork.frontend.World
+
+class EvaluatorProvider(val world: World) : ExecutionContextProvider {
+  override fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol, nativeRegistry: NativeRegistry): ExecutionContext {
+    val evaluator = Evaluator(world)
+    nativeRegistry.forEachProvider { form, provider ->
+      evaluator.addNativeProvider(form, AdaptedNativeProvider(provider))
+    }
+    val slab = evaluator.slabContext(importLocator)
+    slab.finalizeScope()
+    return EvaluatorExecutionContext(evaluator, slab, entryPointSymbol)
+  }
+}

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

@@ -2,6 +2,6 @@ package gay.pizza.pork.evaluator
 
 import gay.pizza.pork.ast.gen.ArgumentSpec
 
-interface NativeProvider {
+interface ExpandedNativeProvider {
   fun provideNativeFunction(definitions: List<String>, arguments: List<ArgumentSpec>, inside: SlabContext): CallableFunction
 }

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

@@ -1,6 +1,7 @@
 package gay.pizza.pork.evaluator
 
 import gay.pizza.pork.ast.gen.FunctionDefinition
+import gay.pizza.pork.execution.ArgumentList
 
 class FunctionContext(val slabContext: SlabContext, val node: FunctionDefinition) : CallableFunction {
   val name: String by lazy { "${slabContext.slab.location.commonFriendlyName} ${node.symbol.id}" }

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

@@ -1,55 +0,0 @@
-package gay.pizza.pork.evaluator
-
-import gay.pizza.pork.ast.gen.ArgumentSpec
-import gay.pizza.pork.common.unused
-
-class InternalNativeProvider(val quiet: Boolean = false) : NativeProvider {
-  private val functions = mutableMapOf(
-    "print" to CallableFunction(::printValues),
-    "println" to CallableFunction(::printLine),
-    "listSet" to CallableFunction(::setInList),
-    "listInitWith" to CallableFunction(::listInitWith)
-  )
-
-  fun add(name: String, function: CallableFunction) {
-    functions[name] = function
-  }
-
-  override fun provideNativeFunction(
-    definitions: List<String>,
-    arguments: List<ArgumentSpec>,
-    inside: SlabContext
-  ): CallableFunction {
-    val definition = definitions[0]
-    return functions[definition] ?: throw RuntimeException("Unknown Internal Function: $definition")
-  }
-
-  private fun printValues(arguments: ArgumentList, stack: CallStack): Any {
-    unused(stack)
-    if (quiet || arguments.isEmpty()) return None
-    print(arguments.joinToString(" "))
-    return None
-  }
-
-  private fun printLine(arguments: ArgumentList, stack: CallStack): Any {
-    unused(stack)
-    if (quiet) return None
-    println(arguments.joinToString(" "))
-    return None
-  }
-
-  private fun setInList(arguments: ArgumentList, stack: CallStack): Any {
-    unused(stack)
-    @Suppress("UNCHECKED_CAST")
-    val list = arguments[0] as MutableList<Any>
-    val value = arguments[2]
-    list[(arguments[1] as Number).toInt()] = value
-    return value
-  }
-
-  private fun listInitWith(arguments: ArgumentList, stack: CallStack): Any {
-    unused(stack)
-    val size = (arguments[0] as Number).toInt()
-    return MutableList(size) { arguments[1] }
-  }
-}

evaluator/src/main/kotlin/gay/pizza/pork/evaluator/None.kt

@@ -1,3 +0,0 @@
-package gay.pizza.pork.evaluator
-
-data object None

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

@@ -1,5 +1,7 @@
 package gay.pizza.pork.evaluator
 
+import gay.pizza.pork.execution.None
+
 class Scope(
   var parent: Scope? = null,
   var inherits: List<Scope> = emptyList(),

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

@@ -16,7 +16,7 @@ class SlabContext(val slab: Slab, val evaluator: Evaluator, rootScope: Scope) {
 
   fun ensureImportedContextsExist() {
     for (importedSlab in slab.importedSlabs) {
-      evaluator.context(importedSlab)
+      evaluator.slabContext(importedSlab)
     }
   }
 
@@ -54,7 +54,7 @@ class SlabContext(val slab: Slab, val evaluator: Evaluator, rootScope: Scope) {
 
   private fun processFinalImportScopes() {
     for (importedSlab in slab.importedSlabs) {
-      val importedSlabContext = evaluator.context(importedSlab)
+      val importedSlabContext = evaluator.slabContext(importedSlab)
       importedSlabContext.processFinalImportScopes()
       internalScope.inherit(importedSlabContext.externalScope)
     }

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

@@ -1,5 +1,7 @@
 package gay.pizza.pork.evaluator
 
+import gay.pizza.pork.execution.None
+
 class ValueStore(var value: Any, var type: ValueStoreType) {
   var isCurrentlyFree = false
 

examples/count.pork

@@ -1,11 +1,7 @@
 export func main() {
   var x = 1
   while x <= 5 {
-    if x == 3 {
-      println("The value is 3")
-    } else {
-      println("The value is not 3")
-    }
+    println(x)
     x++
   }
 }

execution/src/main/kotlin/gay/pizza/pork/execution/ArgumentList.kt

@@ -0,0 +1,5 @@
+package gay.pizza.pork.execution
+
+typealias ArgumentList = List<Any>
+
+inline fun <reified T> ArgumentList.at(index: Int): T = this[index] as T

execution/src/main/kotlin/gay/pizza/pork/execution/ExecutionContextProvider.kt

@@ -4,5 +4,5 @@ import gay.pizza.pork.ast.gen.Symbol
 import gay.pizza.pork.frontend.ImportLocator
 
 interface ExecutionContextProvider {
-  fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol): ExecutionContext
+  fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol, nativeRegistry: NativeRegistry): ExecutionContext
 }

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

@@ -0,0 +1,45 @@
+package gay.pizza.pork.execution
+
+class InternalNativeProvider(val quiet: Boolean = false) : NativeProvider {
+  private val functions = mutableMapOf(
+    "print" to NativeFunction(::printValues),
+    "println" to NativeFunction(::printLine),
+    "listSet" to NativeFunction(::setInList),
+    "listInitWith" to NativeFunction(::listInitWith)
+  )
+
+  fun add(name: String, function: NativeFunction) {
+    functions[name] = function
+  }
+
+  override fun provideNativeFunction(definitions: List<String>): NativeFunction {
+    val definition = definitions[0]
+    return functions[definition] ?:
+      throw RuntimeException("Unknown internal function: $definition")
+  }
+
+  private fun printValues(arguments: ArgumentList): Any {
+    if (quiet || arguments.isEmpty()) return None
+    print(arguments.at<List<*>>(0).joinToString(" ") { it.toString() })
+    return None
+  }
+
+  private fun printLine(arguments: ArgumentList): Any {
+    if (quiet) return None
+    println(arguments.at<List<*>>(0).joinToString(" ") { it.toString() })
+    return Unit
+  }
+
+  private fun setInList(arguments: ArgumentList): Any {
+    @Suppress("UNCHECKED_CAST")
+    val list = arguments[0] as MutableList<Any>
+    val value = arguments[2]
+    list[(arguments.at<Number>(0)).toInt()] = value
+    return value
+  }
+
+  private fun listInitWith(arguments: ArgumentList): Any {
+    val size = arguments.at<Number>(0).toInt()
+    return MutableList(size) { arguments[1] }
+  }
+}

execution/src/main/kotlin/gay/pizza/pork/execution/NativeFunction.kt

@@ -0,0 +1,5 @@
+package gay.pizza.pork.execution
+
+fun interface NativeFunction {
+  fun invoke(args: ArgumentList): Any
+}

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

@@ -0,0 +1,5 @@
+package gay.pizza.pork.execution
+
+interface NativeProvider {
+  fun provideNativeFunction(definitions: List<String>): NativeFunction
+}

execution/src/main/kotlin/gay/pizza/pork/execution/NativeRegistry.kt

@@ -0,0 +1,18 @@
+package gay.pizza.pork.execution
+
+class NativeRegistry {
+  private val providers = mutableMapOf<String, NativeProvider>()
+
+  fun add(form: String, provider: NativeProvider) {
+    providers[form] = provider
+  }
+
+  fun forEachProvider(block: (String, NativeProvider) -> Unit) {
+    for ((form, provider) in providers) {
+      block(form, provider)
+    }
+  }
+
+  fun of(form: String): NativeProvider =
+    providers[form] ?: throw RuntimeException("Unknown native form: ${form}")
+}

execution/src/main/kotlin/gay/pizza/pork/execution/None.kt

@@ -0,0 +1,3 @@
+package gay.pizza.pork.execution
+
+data object None

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

@@ -4,11 +4,13 @@ import com.kenai.jffi.*
 import com.kenai.jffi.Function
 import gay.pizza.pork.ast.gen.ArgumentSpec
 import gay.pizza.pork.evaluator.*
+import gay.pizza.pork.execution.ArgumentList
+import gay.pizza.pork.execution.None
 import kotlin.io.path.Path
 import kotlin.io.path.absolutePathString
 import kotlin.io.path.exists
 
-class FfiNativeProvider : NativeProvider {
+class FfiNativeProvider : ExpandedNativeProvider {
   private val internalFunctions = mutableMapOf<String, (ArgumentList) -> Any>(
     "ffiStructDefine" to ::ffiStructDefine,
     "ffiStructAllocate" to ::ffiStructAllocate,

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

@@ -2,7 +2,7 @@ package gay.pizza.pork.ffi
 
 import com.kenai.jffi.InvocationBuffer
 import com.kenai.jffi.MemoryIO
-import gay.pizza.pork.evaluator.None
+import gay.pizza.pork.execution.None
 
 enum class FfiPrimitiveType(
   val id: kotlin.String,

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

@@ -3,7 +3,7 @@ package gay.pizza.pork.ffi
 import com.kenai.jffi.InvocationBuffer
 import com.kenai.jffi.MemoryIO
 import com.kenai.jffi.Struct
-import gay.pizza.pork.evaluator.None
+import gay.pizza.pork.execution.None
 
 class FfiStruct(val ffiTypeRegistry: FfiTypeRegistry) : FfiType {
   private val fields = LinkedHashMap<String, FfiStructField>()

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

@@ -3,12 +3,12 @@ package gay.pizza.pork.ffi
 import gay.pizza.pork.ast.gen.ArgumentSpec
 import gay.pizza.pork.evaluator.CallableFunction
 import gay.pizza.pork.evaluator.SlabContext
-import gay.pizza.pork.evaluator.NativeProvider
-import gay.pizza.pork.evaluator.None
+import gay.pizza.pork.evaluator.ExpandedNativeProvider
+import gay.pizza.pork.execution.None
 import java.lang.invoke.MethodHandles
 import java.lang.invoke.MethodType
 
-class JavaNativeProvider : NativeProvider {
+class JavaNativeProvider : ExpandedNativeProvider {
   private val lookup = MethodHandles.lookup()
 
   override fun provideNativeFunction(

frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt

@@ -104,7 +104,7 @@ class ExternalSymbolUsageAnalyzer : FunctionLevelVisitor<Unit>() {
   }
 
   override fun visitSetAssignment(node: SetAssignment) {
-    node.visitChildren(this)
+    node.value.visit(this)
   }
 
   override fun visitStringLiteral(node: StringLiteral) {

minimal/build.gradle.kts

@@ -10,6 +10,7 @@ dependencies {
   api(project(":parser"))
   api(project(":frontend"))
   api(project(":evaluator"))
+  api(project(":vm"))
   api(project(":stdlib"))
   api(project(":ffi"))
   implementation(project(":common"))

minimal/src/main/kotlin/gay/pizza/pork/minimal/ExecutionType.kt

@@ -0,0 +1,11 @@
+package gay.pizza.pork.minimal
+
+import gay.pizza.pork.evaluator.EvaluatorProvider
+import gay.pizza.pork.execution.ExecutionContextProvider
+import gay.pizza.pork.frontend.World
+import gay.pizza.pork.vm.VirtualMachineProvider
+
+enum class ExecutionType(val id: String, val create: (World) -> ExecutionContextProvider) {
+  Evaluator("evaluator", { world -> EvaluatorProvider(world) }),
+  VirtualMachine("virtual-machine", { world -> VirtualMachineProvider(world) })
+}

minimal/src/main/kotlin/gay/pizza/pork/minimal/Tool.kt

@@ -2,8 +2,13 @@ package gay.pizza.pork.minimal
 
 import gay.pizza.pork.ast.gen.CompilationUnit
 import gay.pizza.pork.ast.gen.NodeVisitor
+import gay.pizza.pork.ast.gen.Symbol
 import gay.pizza.pork.ast.gen.visit
 import gay.pizza.pork.evaluator.*
+import gay.pizza.pork.execution.ExecutionContext
+import gay.pizza.pork.execution.ExecutionContextProvider
+import gay.pizza.pork.execution.InternalNativeProvider
+import gay.pizza.pork.execution.NativeRegistry
 import gay.pizza.pork.ffi.FfiNativeProvider
 import gay.pizza.pork.ffi.JavaAutogenContentSource
 import gay.pizza.pork.ffi.JavaNativeProvider
@@ -36,20 +41,13 @@ abstract class Tool {
 
   fun <T> visit(visitor: NodeVisitor<T>): T = visitor.visit(parse())
 
-  fun loadMainFunction(setupEvaluator: Evaluator.() -> Unit = {}): CallableFunction {
-    val world = buildWorld()
-    val evaluator = Evaluator(world)
-    setupEvaluator(evaluator)
-    val resultingScope = evaluator.evaluate(rootImportLocator)
-    return resultingScope.value("main") as CallableFunction
-  }
+  fun createExecutionContextProvider(type: ExecutionType): ExecutionContextProvider =
+    type.create(buildWorld())
 
-  fun loadMainFunctionStandard(quiet: Boolean = false): CallableFunction =
-    loadMainFunction(setupEvaluator = {
-      addNativeProvider("internal", InternalNativeProvider(quiet = quiet))
-      addNativeProvider("ffi", FfiNativeProvider())
-      addNativeProvider("java", JavaNativeProvider())
-    })
+  fun createExecutionContext(type: ExecutionType, symbol: Symbol, nativeRegistry: NativeRegistry): ExecutionContext {
+    val executionContextProvider = createExecutionContextProvider(type)
+    return executionContextProvider.prepare(rootImportLocator, symbol, nativeRegistry)
+  }
 
   fun buildWorld(): World {
     val fileContentSource = createContentSource()
@@ -59,9 +57,4 @@ abstract class Tool {
     dynamicImportSource.addContentSource("java", JavaAutogenContentSource)
     return World(dynamicImportSource)
   }
-
-  fun run(quiet: Boolean = false) {
-    val main = loadMainFunctionStandard(quiet = quiet)
-    main.call(emptyList(), CallStack())
-  }
 }

minimal/src/main/kotlin/gay/pizza/pork/minimal/main.kt

@@ -1,7 +1,10 @@
 package gay.pizza.pork.minimal
 
 import gay.pizza.dough.fs.PlatformFsProvider
+import gay.pizza.pork.ast.gen.Symbol
 import gay.pizza.pork.evaluator.Scope
+import gay.pizza.pork.execution.InternalNativeProvider
+import gay.pizza.pork.execution.NativeRegistry
 import kotlin.system.exitProcess
 
 fun main(args: Array<String>) {
@@ -11,5 +14,12 @@ fun main(args: Array<String>) {
   }
   val path = PlatformFsProvider.resolve(args[0])
   val tool = FileTool(path)
-  tool.run()
+  val nativeRegistry = NativeRegistry()
+  nativeRegistry.add("internal", InternalNativeProvider(quiet = false))
+  val main = tool.createExecutionContext(
+    ExecutionType.Evaluator,
+    Symbol("main"),
+    nativeRegistry
+  )
+  main.execute()
 }

support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/PorkElementFactory.kt

@@ -39,6 +39,7 @@ object PorkElementFactory {
       NodeType.ForIn -> ForInElement(node)
       NodeType.Break -> BreakElement(node)
       NodeType.Continue -> ContinueElement(node)
+      NodeType.Return -> ReturnElement(node)
       NodeType.NoneLiteral -> NoneLiteralElement(node)
       NodeType.NativeFunctionDescriptor -> NativeFunctionDescriptorElement(node)
       NodeType.IndexedBy -> IndexedByElement(node)

support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/ReturnElement.kt

@@ -0,0 +1,15 @@
+// GENERATED CODE FROM PORK AST CODEGEN
+package gay.pizza.pork.idea.psi.gen
+
+import com.intellij.lang.ASTNode
+import com.intellij.navigation.ItemPresentation
+import gay.pizza.pork.idea.psi.PorkElementHelpers
+import javax.swing.Icon
+
+class ReturnElement(node: ASTNode) : PorkElement(node) {
+  override fun getIcon(flags: Int): Icon? =
+    PorkElementHelpers.iconOf(this)
+
+  override fun getPresentation(): ItemPresentation? =
+    PorkElementHelpers.presentationOf(this)
+}

tool/src/main/kotlin/gay/pizza/pork/tool/CompileCommand.kt

@@ -6,7 +6,6 @@ import gay.pizza.dough.fs.PlatformFsProvider
 import gay.pizza.pork.ast.gen.Symbol
 import gay.pizza.pork.compiler.Compiler
 import gay.pizza.pork.minimal.FileTool
-import gay.pizza.pork.vm.VirtualMachine
 
 class CompileCommand : CliktCommand(help = "Compile Pork to Bytecode", name = "compile") {
   val path by argument("file")
@@ -32,7 +31,5 @@ class CompileCommand : CliktCommand(help = "Compile Pork to Bytecode", name = "c
         println("  ${symbol.offset + index.toUInt()} ${op}${annotation}")
       }
     }
-    val vm = VirtualMachine(compiledWorld)
-    vm.execute()
   }
 }

tool/src/main/kotlin/gay/pizza/pork/tool/RunCommand.kt

@@ -2,33 +2,33 @@ package gay.pizza.pork.tool
 
 import com.github.ajalt.clikt.core.CliktCommand
 import com.github.ajalt.clikt.parameters.arguments.argument
+import com.github.ajalt.clikt.parameters.options.default
 import com.github.ajalt.clikt.parameters.options.flag
 import com.github.ajalt.clikt.parameters.options.option
+import com.github.ajalt.clikt.parameters.types.enum
 import gay.pizza.dough.fs.PlatformFsProvider
-import gay.pizza.pork.evaluator.*
+import gay.pizza.pork.ast.gen.Symbol
+import gay.pizza.pork.execution.InternalNativeProvider
+import gay.pizza.pork.execution.NativeRegistry
+import gay.pizza.pork.minimal.ExecutionType
 import gay.pizza.pork.minimal.FileTool
 
 class RunCommand : CliktCommand(help = "Run Program", name = "run") {
   val loop by option("--loop", help = "Loop Program").flag()
   val measure by option("--measure", help = "Measure Time").flag()
   val quiet by option("--quiet", help = "Silence Prints").flag()
-  val dumpScope by option("--dump-scope", help = "Dump Scope").flag()
+  val executionType by option("--execution-type", "-E")
+    .enum<ExecutionType> { it.id }
+    .default(ExecutionType.VirtualMachine)
   val path by argument("file")
 
   override fun run() {
     val tool = FileTool(PlatformFsProvider.resolve(path))
-    val main = tool.loadMainFunctionStandard(quiet = quiet)
-
-    if (dumpScope) {
-      val functionContext = main as FunctionContext
-      val internalScope = functionContext.slabContext.internalScope
-      internalScope.crawlScopePath { key, path ->
-        println("[scope] $key [${path.joinToString(" -> ")}]")
-      }
-    }
-
+    val nativeRegistry = NativeRegistry()
+    nativeRegistry.add("internal", InternalNativeProvider(quiet = quiet))
+    val main = tool.createExecutionContext(executionType, Symbol("main"), nativeRegistry)
     maybeLoopAndMeasure(loop, measure) {
-      main.call(emptyList(), CallStack())
+      main.execute()
     }
   }
 }

vm/src/main/kotlin/gay/pizza/pork/vm/InternalMachine.kt

@@ -2,8 +2,9 @@ package gay.pizza.pork.vm
 
 import gay.pizza.pork.bytecode.CompiledWorld
 import gay.pizza.pork.bytecode.ConstantTag
+import gay.pizza.pork.execution.NativeRegistry
 
-class InternalMachine(val world: CompiledWorld, val handlers: List<OpHandler>) {
+class InternalMachine(val world: CompiledWorld, val nativeRegistry: NativeRegistry, val handlers: List<OpHandler>) {
   private val inlined = world.code.map { op ->
     val handler = handlers.firstOrNull { it.code == op.code } ?:
       throw VirtualMachineException("Opcode ${op.code.name} does not have a handler.")

vm/src/main/kotlin/gay/pizza/pork/vm/StandardOpHandlers.kt

@@ -0,0 +1,56 @@
+package gay.pizza.pork.vm
+
+import gay.pizza.pork.vm.ops.*
+
+val StandardOpHandlers: List<OpHandler> = listOf(
+  IntegerOpHandler,
+  ConstantOpHandler,
+
+  TrueOpHandler,
+  FalseOpHandler,
+
+  NoneOpHandler,
+
+  ListMakeOpHandler,
+  ListSizeOpHandler,
+
+  IndexOpHandler,
+
+  AndOpHandler,
+  OrOpHandler,
+  NotOpHandler,
+
+  CompareEqualOpHandler,
+  CompareLesserOpHandler,
+  CompareGreaterOpHandler,
+  CompareLesserEqualOpHandler,
+  CompareGreaterEqualOpHandler,
+
+  AddOpHandler,
+  SubtractOpHandler,
+  MultiplyOpHandler,
+
+  UnaryMinusOpHandler,
+  UnaryPlusOpHandler,
+
+  BinaryAndOpHandler,
+  BinaryOrOpHandler,
+  BinaryNotOpHandler,
+
+  JumpOpHandler,
+  JumpIfOpHandler,
+
+  LoadLocalOpHandler,
+  StoreLocalOpHandler,
+
+  ReturnAddressOpHandler,
+  CallOpHandler,
+  ReturnOpHandler,
+
+  NativeOpHandler,
+
+  ScopeInOpHandler,
+  ScopeOutOpHandler,
+
+  EndOpHandler
+)

vm/src/main/kotlin/gay/pizza/pork/vm/VirtualMachine.kt

@@ -2,57 +2,21 @@ package gay.pizza.pork.vm
 
 import gay.pizza.pork.bytecode.CompiledWorld
 import gay.pizza.pork.execution.ExecutionContext
-import gay.pizza.pork.vm.ops.*
+import gay.pizza.pork.execution.NativeRegistry
 
-class VirtualMachine(world: CompiledWorld) : ExecutionContext {
-  private val internal = InternalMachine(world, listOf(
-    IntegerOpHandler,
-    ConstantOpHandler,
-
-    TrueOpHandler,
-    FalseOpHandler,
-
-    NoneOpHandler,
-
-    ListMakeOpHandler,
-    ListSizeOpHandler,
-
-    IndexOpHandler,
-
-    AndOpHandler,
-    OrOpHandler,
-    NotOpHandler,
-
-    CompareEqualOpHandler,
-    CompareLesserEqualOpHandler,
-    CompareGreaterEqualOpHandler,
-
-    AddOpHandler,
-
-    JumpOpHandler,
-    JumpIfOpHandler,
-
-    LoadLocalOpHandler,
-    StoreLocalOpHandler,
-
-    ReturnAddressOpHandler,
-    CallOpHandler,
-    ReturnOpHandler,
-
-    NativeOpHandler,
-
-    ScopeInOpHandler,
-    ScopeOutOpHandler,
-
-    EndOpHandler
-  ))
+class VirtualMachine(world: CompiledWorld, nativeRegistry: NativeRegistry) : ExecutionContext {
+  private val internal = InternalMachine(
+    world = world,
+    nativeRegistry = nativeRegistry,
+    handlers = StandardOpHandlers
+  )
 
   override fun execute() {
+    internal.reset()
     while (true) {
       if (!internal.step()) {
         break
       }
     }
-    internal.reset()
   }
 }

vm/src/main/kotlin/gay/pizza/pork/vm/VirtualMachineProvider.kt

@@ -4,17 +4,18 @@ import gay.pizza.pork.ast.gen.Symbol
 import gay.pizza.pork.compiler.Compiler
 import gay.pizza.pork.execution.ExecutionContext
 import gay.pizza.pork.execution.ExecutionContextProvider
+import gay.pizza.pork.execution.NativeRegistry
 import gay.pizza.pork.frontend.ImportLocator
 import gay.pizza.pork.frontend.World
 
 class VirtualMachineProvider(val world: World) : ExecutionContextProvider {
-  override fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol): ExecutionContext {
+  override fun prepare(importLocator: ImportLocator, entryPointSymbol: Symbol, nativeRegistry: NativeRegistry): ExecutionContext {
     val compiler = Compiler()
     val slab = world.load(importLocator)
     val compilableSlab = compiler.compilableSlabs.of(slab)
     val compilableSymbol = compilableSlab.resolve(entryPointSymbol) ?:
       throw RuntimeException("Unable to find compilable symbol for entry point '${entryPointSymbol.id}'")
     val compiledWorld = compiler.compile(compilableSymbol)
-    return VirtualMachine(compiledWorld)
+    return VirtualMachine(compiledWorld, nativeRegistry)
   }
 }

vm/src/main/kotlin/gay/pizza/pork/vm/ops/BinaryAndOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object BinaryAndOpHandler : OpHandler(Opcode.BinaryAnd) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val right = machine.pop<Int>()
+    val left = machine.pop<Int>()
+    machine.push(left and right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/BinaryNotOpHandler.kt

@@ -0,0 +1,13 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object BinaryNotOpHandler : OpHandler(Opcode.BinaryNot) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val value = machine.pop<Int>()
+    machine.push(value.inv())
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/BinaryOrOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object BinaryOrOpHandler : OpHandler(Opcode.BinaryOr) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val right = machine.pop<Int>()
+    val left = machine.pop<Int>()
+    machine.push(left or right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/CompareGreaterOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object CompareGreaterOpHandler : OpHandler(Opcode.CompareGreater) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val right = machine.pop<Int>()
+    val left = machine.pop<Int>()
+    machine.push(left > right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/CompareLesserOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object CompareLesserOpHandler : OpHandler(Opcode.CompareLesser) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val right = machine.pop<Int>()
+    val left = machine.pop<Int>()
+    machine.push(left < right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/MultiplyOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object MultiplyOpHandler : OpHandler(Opcode.Multiply) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val left = machine.pop<Int>()
+    val right = machine.pop<Int>()
+    machine.push(left * right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/NativeOpHandler.kt

@@ -7,10 +7,21 @@ import gay.pizza.pork.vm.OpHandler
 
 object NativeOpHandler : OpHandler(Opcode.Native) {
   override fun handle(machine: InternalMachine, op: Op) {
-    val countOfNativeDefs = op.args[1].toInt()
-    val defs = mutableListOf<Any>()
-    for (i in 0 until countOfNativeDefs) {
-      defs.add(machine.pop() as String)
+    val argumentCount = op.args[2]
+    val arguments = mutableListOf<Any>()
+    for (i in 0u until argumentCount) {
+      machine.loadLocal(i)
+      arguments.add(machine.popAnyValue())
     }
+    val formConstant = machine.world.constantPool.read(op.args[0])
+    val form = formConstant.readAsString()
+    val provider = machine.nativeRegistry.of(form)
+    val countOfNativeDefs = op.args[1].toInt()
+    val defs = mutableListOf<String>()
+    for (i in 0 until countOfNativeDefs) {
+      defs.add(machine.pop())
+    }
+    val function = provider.provideNativeFunction(defs)
+    function.invoke(arguments)
   }
 }

vm/src/main/kotlin/gay/pizza/pork/vm/ops/SubtractOpHandler.kt

@@ -0,0 +1,14 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object SubtractOpHandler : OpHandler(Opcode.Subtract) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val left = machine.pop<Int>()
+    val right = machine.pop<Int>()
+    machine.push(left - right)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/UnaryMinusOpHandler.kt

@@ -0,0 +1,13 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object UnaryMinusOpHandler : OpHandler(Opcode.UnaryMinus) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val value = machine.pop<Int>()
+    machine.push(-value)
+  }
+}

vm/src/main/kotlin/gay/pizza/pork/vm/ops/UnaryPlusOpHandler.kt

@@ -0,0 +1,13 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object UnaryPlusOpHandler : OpHandler(Opcode.UnaryPlus) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val value = machine.pop<Int>()
+    machine.push(+value)
+  }
+}