optimizations

internal/ast/ast.go

@@ -127,6 +127,7 @@ func (b *Boolean) expressionNode()      {}
 func (b *Boolean) TokenLiteral() string { return b.Token.Literal }
 func (b *Boolean) String() string       { return b.Token.Literal }
 
+// IntegerLiteral represents a literal integer number and holds an int64 value
 type IntegerLiteral struct {
 	Token token.Token
 	Value int64
@@ -136,6 +137,20 @@ func (il *IntegerLiteral) expressionNode()      {}
 func (il *IntegerLiteral) TokenLiteral() string { return il.Token.Literal }
 func (il *IntegerLiteral) String() string       { return il.Token.Literal }
 
+// FloatLiteral represents a literal floating point number and holds an float64 value
+type FloatLiteral struct {
+	Token token.Token
+	Value float64
+}
+
+func (fl *FloatLiteral) expressionNode() {}
+
+// TokenLiteral prints the literal value of the token associated with this node
+func (fl *FloatLiteral) TokenLiteral() string { return fl.Token.Literal }
+
+// String returns a stringified version of the AST for debugging
+func (fl *FloatLiteral) String() string { return fl.Token.Literal }
+
 type PrefixExpression struct {
 	Token    token.Token // The prefix token, e.g. !
 	Operator string

internal/builtins/len.go

@@ -23,6 +23,9 @@ func Len(ctx context.Context, args ...object.Object) object.Object {
 	case *object.Hash:
 		return object.Integer{Value: int64(obj.Len())}
 	default:
+		if obj == nil {
+			return newError("TypeError: object is nil")
+		}
 		return newError("TypeError: object of type '%s' has no len()", args[0].Type())
 	}
 }

internal/compiler/compiler.go

@@ -173,8 +173,12 @@ func (c *Compiler) Compile(node ast.Node) error {
 		}
 
 	case *ast.IntegerLiteral:
-		integer := object.Integer{Value: node.Value}
-		c.emit(code.OpConstant, c.addConstant(integer))
+		i := object.Integer{Value: node.Value}
+		c.emit(code.OpConstant, c.addConstant(i))
+
+	case *ast.FloatLiteral:
+		f := object.Float{Value: node.Value}
+		c.emit(code.OpConstant, c.addConstant(f))
 
 	case *ast.Null:
 		c.emit(code.OpNull)

internal/compiler/compiler_test.go

@@ -165,6 +165,78 @@ func TestIntegerArithmetic(t *testing.T) {
 	runCompilerTests(t, tests)
 }
 
+func TestFloatingPointArithmetic(t *testing.T) {
+	tests := []compilerTestCase{
+		{
+			input:             "1.2 + 2.3",
+			expectedConstants: []interface{}{1.2, 2.3},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpAdd),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+		{
+			input:             "1.2; 2.3",
+			expectedConstants: []interface{}{1.2, 2.3},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpPop),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+		{
+			input:             "2.5 - 0.5",
+			expectedConstants: []interface{}{2.5, 0.5},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpSub),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+		{
+			input:             "1.2 * 2.3",
+			expectedConstants: []interface{}{1.2, 2.3},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpMul),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+		{
+			input:             "5.0 / 2.0",
+			expectedConstants: []interface{}{5.0, 2.0},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpDiv),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+		{
+			input:             "-2.5",
+			expectedConstants: []interface{}{2.5},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpMinus),
+				code.Make(code.OpPop),
+				code.Make(code.OpHalt),
+			},
+		},
+	}
+
+	runCompilerTests(t, tests)
+}
+
 func TestBooleanExpressions(t *testing.T) {
 	tests := []compilerTestCase{
 		{

internal/evaluator/evaluator.go

@@ -133,6 +133,9 @@ func Eval(ctx context.Context, node ast.Node, env *object.Environment) object.Ob
 	case *ast.IntegerLiteral:
 		return object.Integer{Value: node.Value}
 
+	case *ast.FloatLiteral:
+		return object.Float{Value: node.Value}
+
 	case *ast.Boolean:
 		return nativeBoolToBooleanObject(node.Value)
 
@@ -401,6 +404,8 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 		return evalBooleanInfixExpression(operator, left, right)
 	case left.Type() == object.IntegerType && right.Type() == object.IntegerType:
 		return evalIntegerInfixExpression(operator, left, right)
+	case left.Type() == right.Type() && left.Type() == object.FloatType:
+		return evalFloatInfixExpression(operator, left, right)
 	case left.Type() == object.StringType && right.Type() == object.StringType:
 		return evalStringInfixExpression(operator, left, right)
 
@@ -409,6 +414,36 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 	}
 }
 
+func evalFloatInfixExpression(operator string, left, right object.Object) object.Object {
+	leftVal := left.(object.Float).Value
+	rightVal := right.(object.Float).Value
+
+	switch operator {
+	case "+":
+		return object.Float{Value: leftVal + rightVal}
+	case "-":
+		return object.Float{Value: leftVal - rightVal}
+	case "*":
+		return object.Float{Value: leftVal * rightVal}
+	case "/":
+		return object.Float{Value: leftVal / rightVal}
+	case "<":
+		return nativeBoolToBooleanObject(leftVal < rightVal)
+	case "<=":
+		return nativeBoolToBooleanObject(leftVal <= rightVal)
+	case ">":
+		return nativeBoolToBooleanObject(leftVal > rightVal)
+	case ">=":
+		return nativeBoolToBooleanObject(leftVal >= rightVal)
+	case "==":
+		return nativeBoolToBooleanObject(leftVal == rightVal)
+	case "!=":
+		return nativeBoolToBooleanObject(leftVal != rightVal)
+	default:
+		return NULL
+	}
+}
+
 func evalBooleanInfixExpression(operator string, left, right object.Object) object.Object {
 	leftVal := left.(object.Boolean).Value
 	rightVal := right.(object.Boolean).Value

internal/evaluator/evaluator_test.go

@@ -57,7 +57,7 @@ func assertEvaluated(t *testing.T, expected interface{}, actual object.Object) {
 func TestEvalExpressions(t *testing.T) {
 	tests := []struct {
 		input    string
-		expected interface{}
+		expected any
 	}{
 		{"5", 5},
 		{"10", 10},
@@ -84,12 +84,15 @@ func TestEvalExpressions(t *testing.T) {
 		{`4 * " "`, "    "},
 		{"1 << 2", 4},
 		{"4 >> 2", 1},
+		{"5.0 / 2.0", 2.5},
 	}
 
 	for _, tt := range tests {
 		evaluated := testEval(tt.input)
 		if expected, ok := tt.expected.(int64); ok {
 			testIntegerObject(t, evaluated, expected)
+		} else if expected, ok := tt.expected.(float64); ok {
+			testFloatObject(t, evaluated, expected)
 		} else if expected, ok := tt.expected.(bool); ok {
 			testBooleanObject(t, evaluated, expected)
 		}
@@ -405,17 +408,45 @@ func TestClosures(t *testing.T) {
 	testIntegerObject(t, testEval(input), 4)
 }
 
+func TestIntegerLiteral(t *testing.T) {
+	input := `2`
+
+	evaluated := testEval(input)
+	obj, ok := evaluated.(object.Integer)
+	if !ok {
+		t.Fatalf("object is not Integer. got=%T (%+v)", evaluated, evaluated)
+	}
+
+	if obj.Value != 2 {
+		t.Errorf("Integer has wrong value. got=%q", obj.Value)
+	}
+}
+
+func TestFloatLiteral(t *testing.T) {
+	input := `2.5`
+
+	evaluated := testEval(input)
+	obj, ok := evaluated.(object.Float)
+	if !ok {
+		t.Fatalf("object is not Float. got=%T (%+v)", evaluated, evaluated)
+	}
+
+	if obj.Value != 2.5 {
+		t.Errorf("Float has wrong value. got=%f", obj.Value)
+	}
+}
+
 func TestStringLiteral(t *testing.T) {
 	input := `"Hello World!"`
 
 	evaluated := testEval(input)
-	str, ok := evaluated.(object.String)
+	obj, ok := evaluated.(object.String)
 	if !ok {
 		t.Fatalf("object is not String. got=%T (+%v)", evaluated, evaluated)
 	}
 
-	if str.Value != "Hello World!" {
-		t.Errorf("String has wrong value. got=%q", str.Value)
+	if obj.Value != "Hello World!" {
+		t.Errorf("String has wrong value. got=%q", obj.Value)
 	}
 }
 
@@ -803,6 +834,20 @@ func testEval(input string) object.Object {
 	return Eval(context.New(), program, env)
 }
 
+func testFloatObject(t *testing.T, obj object.Object, expected float64) bool {
+	result, ok := obj.(object.Float)
+	if !ok {
+		t.Errorf("object is not Float. got=%T (%+v)", obj, obj)
+		return false
+	}
+	if result.Value != expected {
+		t.Errorf("object has wrong value. got=%f, want=%f",
+			result.Value, expected)
+		return false
+	}
+	return true
+}
+
 func testIntegerObject(t *testing.T, obj object.Object, expected int64) bool {
 	result, ok := obj.(object.Integer)
 	if !ok {

internal/lexer/lexer.go

@@ -182,9 +182,7 @@ func (l *Lexer) NextToken() token.Token {
 			tok.Type = token.LookupIdent(tok.Literal)
 			return tok
 		} else if isDigit(l.ch) {
-			tok.Type = token.INT
-			tok.Literal = l.readNumber()
-			return tok
+			return l.readNumber()
 		} else {
 			tok = newToken(token.ILLEGAL, l.ch)
 		}
@@ -209,12 +207,22 @@ func (l *Lexer) readIdentifier() string {
 	return l.input[position:l.position]
 }
 
-func (l *Lexer) readNumber() string {
+func (l *Lexer) readNumber() token.Token {
 	position := l.position
 	for isDigit(l.ch) {
 		l.readChar()
 	}
-	return l.input[position:l.position]
+	intPart := l.input[position:l.position]
+	if l.ch == '.' {
+		l.readChar()
+		position := l.position
+		for isDigit(l.ch) {
+			l.readChar()
+		}
+		fracPart := l.input[position:l.position]
+		return token.Token{Type: token.FLOAT, Literal: intPart + "." + fracPart}
+	}
+	return token.Token{Type: token.INT, Literal: intPart}
 }
 
 func isLetter(ch byte) bool {

internal/lexer/lexer_test.go

@@ -210,3 +210,35 @@ c := "\r\n\t"
 	}
 
 }
+
+func TestFloats(t *testing.T) {
+	input := `2.5
+3.14
+`
+
+	tests := []struct {
+		expectedType    token.TokenType
+		expectedLiteral string
+	}{
+		{token.FLOAT, "2.5"},
+		{token.FLOAT, "3.14"},
+		{token.EOF, ""},
+	}
+
+	lexer := New(input)
+
+	for i, test := range tests {
+		token := lexer.NextToken()
+
+		if token.Type != test.expectedType {
+			t.Fatalf("tests[%d] - token type wrong. expected=%q, got=%q",
+				i, test.expectedType, token.Type)
+		}
+
+		if token.Literal != test.expectedLiteral {
+			t.Fatalf("tests[%d] - literal wrong. expected=%q, got=%q",
+				i, test.expectedLiteral, token.Literal)
+		}
+	}
+
+}

internal/object/float.go

@@ -0,0 +1,111 @@
+package object
+
+import (
+	"fmt"
+	"math"
+)
+
+// Float is the floating-point number type used to represent float literals and holds
+// an internal float64 value
+type Float struct {
+	Value float64
+}
+
+func (f Float) Bool() bool {
+	return f.Value != 0
+}
+
+func (f Float) Add(other Object) (Object, error) {
+	switch obj := other.(type) {
+	case Float:
+		return Float{f.Value + obj.Value}, nil
+	default:
+		return nil, NewBinaryOpError(f, other, "+")
+	}
+}
+
+func (f Float) Sub(other Object) (Object, error) {
+	switch obj := other.(type) {
+	case Float:
+		return Float{f.Value - obj.Value}, nil
+	default:
+		return nil, NewBinaryOpError(f, other, "-")
+	}
+}
+
+func (f Float) Mul(other Object) (Object, error) {
+	switch obj := other.(type) {
+	case Float:
+		return Float{f.Value * obj.Value}, nil
+	case String:
+		return obj.Mul(f)
+	case *Array:
+		return obj.Mul(f)
+	default:
+		return nil, NewBinaryOpError(f, other, "*")
+	}
+}
+
+func (f Float) Div(other Object) (Object, error) {
+	switch obj := other.(type) {
+	case Float:
+		if obj.Value == 0 {
+			return nil, NewDivisionByZeroError(f)
+		}
+		return Float{f.Value / obj.Value}, nil
+	default:
+		return nil, NewBinaryOpError(f, other, "/")
+	}
+}
+
+func (f Float) Mod(other Object) (Object, error) {
+	switch obj := other.(type) {
+	case Float:
+		return Float{math.Mod(f.Value, obj.Value)}, nil
+	default:
+		return nil, NewBinaryOpError(f, other, "%")
+	}
+}
+
+func (f Float) LogicalNot() Object {
+	return Boolean{!f.Bool()}
+}
+
+func (f Float) Negate() Object {
+	return Float{-f.Value}
+}
+
+func (f Float) Compare(other Object) int {
+	switch obj := other.(type) {
+	case Float:
+		if f.Value < obj.Value {
+			return -1
+		}
+		if f.Value > obj.Value {
+			return 1
+		}
+		return 0
+	default:
+		return -1
+	}
+}
+
+func (f Float) String() string {
+	return f.Inspect()
+}
+
+// Copy implements the Copyable interface
+func (i Float) Copy() Object {
+	return Float{Value: i.Value}
+}
+
+// Hash implements the Hasher interface
+func (i Float) Hash() HashKey {
+	return HashKey{Type: i.Type(), Value: uint64(i.Value)}
+}
+
+// Type returns the type of the object
+func (i Float) Type() Type { return FloatType }
+
+// Inspect returns a stringified version of the object for debugging
+func (i Float) Inspect() string { return fmt.Sprintf("%f", i.Value) }

internal/object/object.go

@@ -11,6 +11,7 @@ type Type int
 const (
 	NullType = iota
 	IntegerType
+	FloatType
 	StringType
 	BooleanType
 	ReturnType
@@ -30,6 +31,8 @@ func (t Type) String() string {
 		return "null"
 	case IntegerType:
 		return "int"
+	case FloatType:
+		return "float"
 	case StringType:
 		return "str"
 	case BooleanType:

internal/parser/parser.go

@@ -82,6 +82,7 @@ func New(fn string, l *lexer.Lexer) *Parser {
 	p.prefixParseFns = make(map[token.TokenType]prefixParseFn)
 	p.registerPrefix(token.IDENT, p.parseIdentifier)
 	p.registerPrefix(token.INT, p.parseIntegerLiteral)
+	p.registerPrefix(token.FLOAT, p.parseFloatLiteral)
 	p.registerPrefix(token.MINUS, p.parsePrefixExpression)
 	p.registerPrefix(token.TRUE, p.parseBoolean)
 	p.registerPrefix(token.FALSE, p.parseBoolean)
@@ -622,6 +623,21 @@ func (p *Parser) parseImportExpression() ast.Expression {
 	return expression
 }
 
+func (p *Parser) parseFloatLiteral() ast.Expression {
+	lit := &ast.FloatLiteral{Token: p.curToken}
+
+	value, err := strconv.ParseFloat(p.curToken.Literal, 64)
+	if err != nil {
+		msg := fmt.Sprintf("could not parse %q as float", p.curToken.Literal)
+		p.errors = append(p.errors, msg)
+		return nil
+	}
+
+	lit.Value = value
+
+	return lit
+}
+
 // Parse parses the input source into a top-level AST for either evaluation
 // or compilation to bytecode. The parameter fn denotes the filename the source
 // originated from.

internal/parser/parser_test.go

@@ -126,6 +126,37 @@ func TestIntegerLiteralExpression(t *testing.T) {
 	}
 }
 
+func TestFloatLiteralExpression(t *testing.T) {
+	input := "2.5;"
+
+	l := lexer.New(input)
+	p := New("<test>", l)
+	program := p.ParseProgram()
+	checkParserErrors(t, p)
+
+	if len(program.Statements) != 1 {
+		t.Fatalf("program has not enough statements. got=%d",
+			len(program.Statements))
+	}
+	stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+	if !ok {
+		t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+			program.Statements[0])
+	}
+
+	literal, ok := stmt.Expression.(*ast.FloatLiteral)
+	if !ok {
+		t.Fatalf("exp not *ast.FloatLiteral. got=%T", stmt.Expression)
+	}
+	if literal.Value != 2.5 {
+		t.Errorf("literal.Value not %f. got=%f", 2.5, literal.Value)
+	}
+	if literal.TokenLiteral() != "2.5" {
+		t.Errorf("literal.TokenLiteral not %s. got=%s", "2.5",
+			literal.TokenLiteral())
+	}
+}
+
 func TestParsingPrefixExpressions(t *testing.T) {
 	prefixTests := []struct {
 		input    string

internal/token/token.go

@@ -17,6 +17,8 @@ const (
 	// Identifiers + literals
 	IDENT = "IDENT" // add, foobar, x, y
 	INT   = "INT"   // 123456
+	// FLOAT is a floating point, e.g: 1.24
+	FLOAT  = "FLOAT"
 	STRING = "STRING"
 
 	// Operators

internal/vm/frame.go

@@ -55,7 +55,3 @@ func (f *frame) ReadUint16() uint16 {
 	f.ip += 2
 	return n
 }
-
-func (f frame) Instructions() code.Instructions {
-	return f.cl.Fn.Instructions
-}

internal/vm/vm.go

@@ -2,6 +2,7 @@ package vm
 
 import (
 	"fmt"
+	"log"
 	"monkey/internal/builtins"
 	"monkey/internal/code"
 	"monkey/internal/compiler"
@@ -12,6 +13,8 @@ import (
 	"monkey/internal/utils"
 	"os"
 	"path/filepath"
+	"sort"
+	"time"
 	"unicode"
 )
 
@@ -335,6 +338,12 @@ func (vm *VM) executeAdd() error {
 			return err
 		}
 		return vm.push(val)
+	case object.Float:
+		val, err := obj.Add(right)
+		if err != nil {
+			return err
+		}
+		return vm.push(val)
 	case object.String:
 		val, err := obj.Add(right)
 		if err != nil {
@@ -368,6 +377,12 @@ func (vm *VM) executeSub() error {
 			return err
 		}
 		return vm.push(val)
+	case object.Float:
+		val, err := obj.Sub(right)
+		if err != nil {
+			return err
+		}
+		return vm.push(val)
 	default:
 		return fmt.Errorf("unsupported types for unary operation: -%s", left.Type())
 	}
@@ -389,6 +404,12 @@ func (vm *VM) executeMul() error {
 			return err
 		}
 		return vm.push(val)
+	case object.Float:
+		val, err := obj.Mul(right)
+		if err != nil {
+			return err
+		}
+		return vm.push(val)
 	case object.String:
 		val, err := obj.Mul(right)
 		if err != nil {
@@ -410,6 +431,12 @@ func (vm *VM) executeDiv() error {
 			return err
 		}
 		return vm.push(val)
+	case object.Float:
+		val, err := obj.Div(right)
+		if err != nil {
+			return err
+		}
+		return vm.push(val)
 	default:
 		return object.NewBinaryOpError(left, right, "/")
 	}
@@ -591,6 +618,8 @@ func (vm *VM) executeNot() error {
 		return vm.push(obj.LogicalNot())
 	case object.Integer:
 		return vm.push(obj.LogicalNot())
+	case object.Float:
+		return vm.push(obj.LogicalNot())
 	case object.Null:
 		return vm.push(obj.LogicalNot())
 	default:
@@ -604,6 +633,8 @@ func (vm *VM) executeMinus() error {
 	switch obj := left.(type) {
 	case object.Integer:
 		return vm.push(obj.Negate())
+	case object.Float:
+		return vm.push(obj.Negate())
 	default:
 		return fmt.Errorf("unsupported types for unary operation: -%s", left.Type())
 	}
@@ -714,6 +745,7 @@ func (vm *VM) callClosure(cl *object.Closure, numArgs int) error {
 func (vm *VM) callBuiltin(builtin object.Builtin, numArgs int) error {
 	args := vm.stack[vm.sp-numArgs : vm.sp]
 
+	log.Printf("args: %+v", args)
 	result := builtin.Fn(vm.ctx, args...)
 	vm.sp = vm.sp - numArgs - 1
 
@@ -764,10 +796,29 @@ func (vm *VM) LastPoppedStackElem() object.Object {
 }
 
 func (vm *VM) Run() (err error) {
+	start := time.Now()
+	freqs := make([]int, 255)
 
 	for err == nil {
 		op := vm.currentFrame().ReadNextOp()
 
+		if vm.debug {
+			freqs[op]++
+		}
+
+		if vm.trace {
+			log.Printf(
+				"%-25s M:%-20s\n",
+				fmt.Sprintf(
+					"%04d %s", vm.currentFrame().ip, op,
+				),
+				fmt.Sprintf(
+					"[ip=%02d fp=%02d, sp=%02d]",
+					vm.currentFrame().ip, vm.fp-1, vm.sp,
+				),
+			)
+		}
+
 		switch op {
 		case code.OpConstant:
 			constIndex := vm.currentFrame().ReadUint16()
@@ -925,6 +976,45 @@ func (vm *VM) Run() (err error) {
 		default:
 			err = fmt.Errorf("unhandled opcode: %s", op)
 		}
+
+		if vm.trace {
+			log.Printf(
+				"%-25s [ip=%02d fp=%02d, sp=%02d]",
+				"", vm.currentFrame().ip, vm.fp-1, vm.sp,
+			)
+			var globals []object.Object
+			for _, obj := range vm.state.Globals {
+				if obj != nil {
+					globals = append(globals, obj)
+				}
+			}
+			log.Printf("%-25s G:%+v", "", globals)
+			log.Printf("%-25s S:%+v", "", vm.stack[:vm.sp])
+			log.Printf("%-25s E:%+v", "", err)
+		}
+	}
+
+	if vm.debug {
+		end := time.Now().Sub(start)
+
+		total := 0
+		opcodes := make([]code.Opcode, 0, len(freqs))
+
+		for i, count := range freqs {
+			opcode := code.Opcode(i)
+			opcodes = append(opcodes, opcode)
+			total += count
+		}
+
+		sort.SliceStable(opcodes, func(i, j int) bool {
+			return freqs[opcodes[i]] > freqs[opcodes[j]]
+		})
+
+		log.Printf("%d instructions executed in %s %d/µs", total, end, total/int(end.Microseconds()))
+		log.Print("Top Instructions:")
+		for _, opcode := range opcodes[:min(len(opcodes), 10)] {
+			log.Printf("%10d %s", freqs[opcode], opcode)
+		}
 	}
 
 	return

internal/vm/vm_test.go

@@ -242,6 +242,21 @@ func TestIntegerArithmetic(t *testing.T) {
 	runVmTests(t, tests)
 }
 
+func TestFloatingPointArithmetic(t *testing.T) {
+	tests := []vmTestCase{
+		{"1.2", 1.2},
+		{"2.3", 2.3},
+		{"1.2 + 2.3", 3.5},
+		{"1.2 - 2.4", -1.2},
+		{"1.2 * 2.4", 2.88},
+		{"5.0 / 2.0", 2.5},
+		{"-2.5", -2.5},
+		{"!1.0", false},
+	}
+
+	runVmTests(t, tests)
+}
+
 func TestBooleanExpressions(t *testing.T) {
 	tests := []vmTestCase{
 		{"true", true},

profile.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"log"
 	"monkey/internal/compiler"
-	"monkey/internal/object"
 	"monkey/internal/parser"
 	"monkey/internal/vm"
 	"os"
@@ -24,7 +23,7 @@ fib := fn(n) {
 	return fib(n-1) + fib(n-2)
 }
 
-print(fib(%d))`
+println(fib(%d))`
 
 func checkErr(err error) {
 	if err != nil {
@@ -39,13 +38,12 @@ func readFile(path string) string {
 	return string(b)
 }
 
-func fileOrDefault() string {
+func fileOrDefault() (string, []string) {
 	if flag.NArg() > 0 {
 		log.Printf("Using %s as program input...", flag.Arg(0))
-		object.Args = flag.Args()[1:]
-		return readFile(flag.Arg(0))
+		return readFile(flag.Arg(0)), flag.Args()[1:]
 	}
-	return defaultCode
+	return defaultCode, flag.Args()[:]
 }
 
 func main() {
@@ -60,7 +58,7 @@ func main() {
 
 	log.Printf("Using %d as n", *n)
 
-	code := fileOrDefault()
+	code, args := fileOrDefault()
 	if strings.Count(code, "%d") > 0 {
 		code = fmt.Sprintf(code, *n)
 	}
@@ -78,7 +76,7 @@ func main() {
 	checkErr(c.Compile(tree))
 	checkErr(pprof.StartCPUProfile(cpuf))
 	defer pprof.StopCPUProfile()
-	mvm := vm.New("<profiler>", c.Bytecode())
+	mvm := vm.New("<profiler>", c.Bytecode(), vm.WithContext(context.New(context.WithArgs(args))))
 	checkErr(mvm.Run())
 	runtime.GC()
 	checkErr(pprof.WriteHeapProfile(heapf))

repl.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"log"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	"golang.org/x/term"
@@ -32,10 +33,11 @@ func REPL(opts *Options) error {
 		return fmt.Errorf("error opening terminal: %w", err)
 	}
 	defer func() {
-		if err := recover(); err != nil {
-			log.Printf("recovered from panic: %s", err)
-		}
 		term.Restore(0, initState)
+		if err := recover(); err != nil {
+			log.Printf("recovered from panic: %s\n", err)
+			log.Printf("stack trace:\n%s", debug.Stack())
+		}
 	}()
 	atexit.Register(func() {
 		term.Restore(0, initState)
@@ -83,7 +85,7 @@ func REPL(opts *Options) error {
 			log.Printf("Bytecode:\n%s\n", c.Bytecode())
 		}
 
-		mvm := vm.New("<stdin>", c.Bytecode(), opts.ToVMOptions()...)
+		mvm := vm.New("<stdin>", c.Bytecode(), append(opts.ToVMOptions(), vm.WithState(state))...)
 
 		if err := mvm.Run(); err != nil {
 			fmt.Fprintf(t, "runtime error: %v\n", err)
@@ -151,7 +153,8 @@ func SimpleREPL(opts *Options) {
 
 	defer func() {
 		if err := recover(); err != nil {
-			log.Printf("recovered from panic: %s", err)
+			log.Printf("recovered from panic: %s\n", err)
+			log.Printf("stack trace: %s\n", debug.Stack())
 		}
 	}()
 
@@ -196,7 +199,7 @@ func SimpleREPL(opts *Options) {
 			log.Printf("Bytecode:\n%s\n", c.Bytecode())
 		}
 
-		mvm := vm.New("<stdin>", c.Bytecode(), opts.ToVMOptions()...)
+		mvm := vm.New("<stdin>", c.Bytecode(), append(opts.ToVMOptions(), vm.WithState(state))...)
 
 		if err := mvm.Run(); err != nil {
 			fmt.Printf("runtime error: %v\n", err)