further improvements

internal/vm/vm.go

@@ -12,6 +12,7 @@ import (
 	"monkey/internal/utils"
 	"os"
 	"path/filepath"
+	"sort"
 	"time"
 	"unicode"
 )
@@ -20,10 +21,6 @@ const StackSize = 2048
 const GlobalsSize = 65536
 const MaxFrames = 1024
 
-var Null = object.Null{}
-var True = object.Boolean{Value: true}
-var False = object.Boolean{Value: false}
-
 func isTruthy(obj object.Object) bool {
 	switch obj := obj.(type) {
 
@@ -114,6 +111,7 @@ func (s *VMState) ExportedHash() *object.Hash {
 
 type VM struct {
 	Debug bool
+	Trace bool
 
 	state *VMState
 
@@ -143,9 +141,9 @@ func (vm *VM) popFrame() Frame {
 
 // New constructs a new monkey-lang bytecode virtual machine
 func New(fn string, bytecode *compiler.Bytecode) *VM {
-	mainFn := &object.CompiledFunction{Instructions: bytecode.Instructions}
-	mainClosure := &object.Closure{Fn: mainFn}
-	mainFrame := NewFrame(mainClosure, 0)
+	mainFn := object.CompiledFunction{Instructions: bytecode.Instructions}
+	mainClosure := object.Closure{Fn: &mainFn}
+	mainFrame := NewFrame(&mainClosure, 0)
 
 	frames := make([]Frame, MaxFrames)
 	frames[0] = mainFrame
@@ -169,9 +167,9 @@ func New(fn string, bytecode *compiler.Bytecode) *VM {
 }
 
 func NewWithState(fn string, bytecode *compiler.Bytecode, state *VMState) *VM {
-	mainFn := &object.CompiledFunction{Instructions: bytecode.Instructions}
-	mainClosure := &object.Closure{Fn: mainFn}
-	mainFrame := NewFrame(mainClosure, 0)
+	mainFn := object.CompiledFunction{Instructions: bytecode.Instructions}
+	mainClosure := object.Closure{Fn: &mainFn}
+	mainFrame := NewFrame(&mainClosure, 0)
 
 	frames := make([]Frame, MaxFrames)
 	frames[0] = mainFrame
@@ -222,13 +220,13 @@ func (vm *VM) executeConstant() error {
 func (vm *VM) executeAssignGlobal() error {
 	globalIndex := vm.currentFrame().ReadUint16()
 	vm.state.Globals[globalIndex] = vm.pop()
-	return vm.push(Null)
+	return vm.push(object.NULL)
 }
 
 func (vm *VM) executeAssignLocal() error {
 	localIndex := vm.currentFrame().ReadUint8()
 	vm.stack[vm.currentFrame().basePointer+int(localIndex)] = vm.pop()
-	return vm.push(Null)
+	return vm.push(object.NULL)
 }
 
 func (vm *VM) executeSetGlobal() error {
@@ -241,7 +239,7 @@ func (vm *VM) executeSetGlobal() error {
 		vm.state.Globals[globalIndex] = ref
 	}
 
-	return vm.push(Null)
+	return vm.push(object.NULL)
 }
 
 func (vm *VM) executeGetGlobal() error {
@@ -259,7 +257,7 @@ func (vm *VM) executeSetLocal() error {
 		vm.stack[vm.currentFrame().basePointer+int(localIndex)] = ref
 	}
 
-	return vm.push(Null)
+	return vm.push(object.NULL)
 }
 
 func (vm *VM) executeGetLocal() error {
@@ -283,15 +281,15 @@ func (vm *VM) executeCurrentClosure() error {
 }
 
 func (vm *VM) executeTrue() error {
-	return vm.push(True)
+	return vm.push(object.TRUE)
 }
 
 func (vm *VM) executeFalse() error {
-	return vm.push(False)
+	return vm.push(object.FALSE)
 }
 
 func (vm *VM) executeNull() error {
-	return vm.push(Null)
+	return vm.push(object.NULL)
 }
 
 func (vm *VM) buildHash(startIndex, endIndex int) (object.Object, error) {
@@ -547,9 +545,9 @@ func (vm *VM) executeEqual() error {
 	if obj, ok := left.(object.Comparable); ok {
 		val := obj.Compare(right)
 		if val == 0 {
-			return vm.push(True)
+			return vm.push(object.TRUE)
 		}
-		return vm.push(False)
+		return vm.push(object.FALSE)
 	}
 
 	return object.NewBinaryOpError(left, right, "==")
@@ -562,9 +560,9 @@ func (vm *VM) executeNotEqual() error {
 	if obj, ok := left.(object.Comparable); ok {
 		val := obj.Compare(right)
 		if val != 0 {
-			return vm.push(True)
+			return vm.push(object.TRUE)
 		}
-		return vm.push(False)
+		return vm.push(object.FALSE)
 	}
 
 	return object.NewBinaryOpError(left, right, "!=")
@@ -577,9 +575,9 @@ func (vm *VM) executeGreaterThan() error {
 	if obj, ok := left.(object.Comparable); ok {
 		val := obj.Compare(right)
 		if val == 1 {
-			return vm.push(True)
+			return vm.push(object.TRUE)
 		}
-		return vm.push(False)
+		return vm.push(object.FALSE)
 	}
 
 	return object.NewBinaryOpError(left, right, ">")
@@ -592,9 +590,9 @@ func (vm *VM) executeGreaterThanOrEqual() error {
 	if obj, ok := left.(object.Comparable); ok {
 		val := obj.Compare(right)
 		if val >= 0 {
-			return vm.push(True)
+			return vm.push(object.TRUE)
 		}
-		return vm.push(False)
+		return vm.push(object.FALSE)
 	}
 
 	return object.NewBinaryOpError(left, right, ">")
@@ -630,7 +628,7 @@ func (vm *VM) executeSetItem() error {
 		if err != nil {
 			return err
 		}
-		return vm.push(Null)
+		return vm.push(object.NULL)
 	}
 
 	return fmt.Errorf(
@@ -664,7 +662,7 @@ func (vm *VM) executeCall() error {
 	switch callee := callee.(type) {
 	case *object.Closure:
 		return vm.callClosure(callee, args)
-	case *object.Builtin:
+	case object.Builtin:
 		return vm.callBuiltin(callee, args)
 	default:
 		return fmt.Errorf(
@@ -727,7 +725,7 @@ func (vm *VM) callClosure(cl *object.Closure, numArgs int) error {
 	return nil
 }
 
-func (vm *VM) callBuiltin(builtin *object.Builtin, numArgs int) error {
+func (vm *VM) callBuiltin(builtin object.Builtin, numArgs int) error {
 	args := vm.stack[vm.sp-numArgs : vm.sp]
 
 	result := builtin.Fn(args...)
@@ -739,7 +737,7 @@ func (vm *VM) callBuiltin(builtin *object.Builtin, numArgs int) error {
 			return err
 		}
 	} else {
-		err := vm.push(Null)
+		err := vm.push(object.NULL)
 		if err != nil {
 			return err
 		}
@@ -761,8 +759,8 @@ func (vm *VM) pushClosure(constIndex, numFree int) error {
 	}
 	vm.sp = vm.sp - numFree
 
-	closure := &object.Closure{Fn: function, Free: free}
-	return vm.push(closure)
+	closure := object.Closure{Fn: function, Free: free}
+	return vm.push(&closure)
 }
 
 func (vm *VM) loadModule(name object.Object) error {
@@ -788,20 +786,38 @@ func (vm *VM) LastPoppedStackElem() object.Object {
 }
 
 func (vm *VM) Run() (err error) {
-	var n int
+	var (
+		op          code.Opcode
+		opcodeFreqs = make(map[code.Opcode]int)
+	)
 
 	if vm.Debug {
 		start := time.Now()
 		defer func() {
-			log.Printf("%d instructions executeuted in %s", n, time.Now().Sub(start))
+			total := 0
+			opcodes := make([]code.Opcode, 0, len(opcodeFreqs))
+
+			for opcode := range opcodeFreqs {
+				opcodes = append(opcodes, opcode)
+			}
+
+			sort.SliceStable(opcodes, func(i, j int) bool {
+				return opcodeFreqs[opcodes[i]] > opcodeFreqs[opcodes[j]]
+			})
+
+			log.Printf("%d instructions executed in %s", total, time.Now().Sub(start))
+			log.Print("Top 10 instructions:")
+			for _, opcode := range opcodes[:10] {
+				log.Printf("%10d %s", opcodeFreqs[opcode], opcode)
+			}
 		}()
 	}
 
 	for err == nil {
-		op := vm.currentFrame().ReadNextOp()
+		op = vm.currentFrame().ReadNextOp()
 
 		if vm.Debug {
-			n++
+			opcodeFreqs[op]++
 			log.Printf(
 				"%-25s %-20s\n",
 				fmt.Sprintf("%04d %s", vm.currentFrame().ip, op),
@@ -949,7 +965,7 @@ func (vm *VM) Run() (err error) {
 			err = fmt.Errorf("unhandled opcode: %s", op)
 		}
 
-		if vm.Debug {
+		if vm.Trace {
 			log.Printf(
 				"%-25s [ip=%02d fp=%02d, sp=%02d]",
 				"", vm.currentFrame().ip, vm.fp-1, vm.sp,