diff --git a/code/code.go b/code/code.go
index 282a348..24d0e4b 100644
--- a/code/code.go
+++ b/code/code.go
@@ -26,6 +26,13 @@ const (
 	OpMul
 	OpDiv
 	OpMod
+	OpOr
+	OpAnd
+	OpNot
+	OpBitwiseOR
+	OpBitwiseXOR
+	OpBitwiseAND
+	OpBitwiseNOT
 	OpTrue
 	OpFalse
 	OpEqual
@@ -33,7 +40,6 @@ const (
 	OpGreaterThan
 	OpGreaterThanEqual
 	OpMinus
-	OpBang
 	OpJumpNotTruthy
 	OpJump
 	OpNull
@@ -71,6 +77,13 @@ var definitions = map[Opcode]*Definition{
 	OpMul:              {"OpMul", []int{}},
 	OpDiv:              {"OpDiv", []int{}},
 	OpMod:              {"OpMod", []int{}},
+	OpOr:               {"OpOr", []int{}},
+	OpAnd:              {"OpAnd", []int{}},
+	OpNot:              {"OpNot", []int{}},
+	OpBitwiseOR:        {"OpBitwiseOR", []int{}},
+	OpBitwiseXOR:       {"OpBitwiseXOR", []int{}},
+	OpBitwiseAND:       {"OpBitwiseAND", []int{}},
+	OpBitwiseNOT:       {"OpBitwiseNOT", []int{}},
 	OpTrue:             {"OpTrue", []int{}},
 	OpFalse:            {"OpFalse", []int{}},
 	OpEqual:            {"OpEqual", []int{}},
@@ -78,7 +91,6 @@ var definitions = map[Opcode]*Definition{
 	OpGreaterThan:      {"OpGreaterThan", []int{}},
 	OpGreaterThanEqual: {"OpGreaterThanEqual", []int{}},
 	OpMinus:            {"OpMinus", []int{}},
-	OpBang:             {"OpBang", []int{}},
 	OpJumpNotTruthy:    {"OpJumpNotTruthy", []int{2}},
 	OpJump:             {"OpJump", []int{2}},
 	OpNull:             {"OpNull", []int{}},
diff --git a/compiler/compiler.go b/compiler/compiler.go
index 240bf9f..1382f4f 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -141,6 +141,16 @@ func (c *Compiler) Compile(node ast.Node) error {
 			c.emit(code.OpDiv)
 		case "%":
 			c.emit(code.OpMod)
+		case "|":
+			c.emit(code.OpBitwiseOR)
+		case "^":
+			c.emit(code.OpBitwiseXOR)
+		case "&":
+			c.emit(code.OpBitwiseAND)
+		case "||":
+			c.emit(code.OpOr)
+		case "&&":
+			c.emit(code.OpAnd)
 		case ">":
 			c.emit(code.OpGreaterThan)
 		case ">=":
@@ -177,7 +187,9 @@ func (c *Compiler) Compile(node ast.Node) error {
 
 		switch node.Operator {
 		case "!":
-			c.emit(code.OpBang)
+			c.emit(code.OpNot)
+		case "~":
+			c.emit(code.OpBitwiseNOT)
 		case "-":
 			c.emit(code.OpMinus)
 		default:
diff --git a/compiler/compiler_test.go b/compiler/compiler_test.go
index 4c05314..771aa2f 100644
--- a/compiler/compiler_test.go
+++ b/compiler/compiler_test.go
@@ -96,6 +96,38 @@ func TestIntegerArithmetic(t *testing.T) {
 				code.Make(code.OpPop),
 			},
 		},
+		{
+			input:             "5 | 2",
+			expectedConstants: []interface{}{5, 2},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpBitwiseOR),
+				code.Make(code.OpPop),
+			},
+		},
+
+		{
+			input:             "5 ^ 2",
+			expectedConstants: []interface{}{5, 2},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpBitwiseXOR),
+				code.Make(code.OpPop),
+			},
+		},
+
+		{
+			input:             "5 & 2",
+			expectedConstants: []interface{}{5, 2},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpBitwiseAND),
+				code.Make(code.OpPop),
+			},
+		},
 	}
 
 	runCompilerTests(t, tests)
@@ -207,12 +239,32 @@ func TestBooleanExpressions(t *testing.T) {
 				code.Make(code.OpPop),
 			},
 		},
+		{
+			input:             "true && false",
+			expectedConstants: []interface{}{},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpTrue),
+				code.Make(code.OpFalse),
+				code.Make(code.OpAnd),
+				code.Make(code.OpPop),
+			},
+		},
+		{
+			input:             "true || false",
+			expectedConstants: []interface{}{},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpTrue),
+				code.Make(code.OpFalse),
+				code.Make(code.OpOr),
+				code.Make(code.OpPop),
+			},
+		},
 		{
 			input:             "!true",
 			expectedConstants: []interface{}{},
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpTrue),
-				code.Make(code.OpBang),
+				code.Make(code.OpNot),
 				code.Make(code.OpPop),
 			},
 		},
@@ -228,20 +280,20 @@ func TestConditionals(t *testing.T) {
 			if (true) { 10 }; 3333;
 			`,
 			constants:    []interface{}{10, 3333},
-			instructions: "0000 LoadTrue\n0001 JumpIfFalse 10\n0004 LoadConstant 0\n0007 Jump 11\n0010 LoadNull\n0011 Pop\n0012 LoadConstant 1\n0015 Pop\n",
+			instructions: "0000 OpTrue\n0001 OpJumpNotTruthy 10\n0004 OpConstant 0\n0007 OpJump 11\n0010 OpNull\n0011 OpPop\n0012 OpConstant 1\n0015 OpPop\n",
 		}, {
 			input: `
 			if (true) { 10 } else { 20 }; 3333;
 			`,
 			constants:    []interface{}{10, 20, 3333},
-			instructions: "0000 LoadTrue\n0001 JumpIfFalse 10\n0004 LoadConstant 0\n0007 Jump 13\n0010 LoadConstant 1\n0013 Pop\n0014 LoadConstant 2\n0017 Pop\n",
+			instructions: "0000 OpTrue\n0001 OpJumpNotTruthy 10\n0004 OpConstant 0\n0007 OpJump 13\n0010 OpConstant 1\n0013 OpPop\n0014 OpConstant 2\n0017 OpPop\n",
 		},
 		{
 			input: `
-			let x = 0; if (true) { x = 1; }; if (false) { x = 2; }
+			x := 0; if (true) { x = 1; }; if (false) { x = 2; }
             `,
 			constants:    []interface{}{0, 1, 2},
-			instructions: "0000 LoadConstant 0\n0003 BindGlobal 0\n0006 Pop\n0007 LoadTrue\n0008 JumpIfFalse 20\n0011 LoadConstant 1\n0014 AssignGlobal 0\n0017 Jump 21\n0020 LoadNull\n0021 Pop\n0022 LoadFalse\n0023 JumpIfFalse 35\n0026 LoadConstant 2\n0029 AssignGlobal 0\n0032 Jump 36\n0035 LoadNull\n0036 Pop\n",
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpTrue\n0008 OpJumpNotTruthy 20\n0011 OpConstant 1\n0014 OpAssignGlobal 0\n0017 OpJump 21\n0020 OpNull\n0021 OpPop\n0022 OpFalse\n0023 OpJumpNotTruthy 35\n0026 OpConstant 2\n0029 OpAssignGlobal 0\n0032 OpJump 36\n0035 OpNull\n0036 OpPop\n",
 		},
 	}
 
@@ -255,7 +307,8 @@ func TestGlobalBindExpressions(t *testing.T) {
             one := 1;
             two := 2;
             `,
-			instructions: "0000 LoadConstant 0\n0003 BindGlobal 0\n0006 Pop\n0007 LoadConstant 1\n0010 BindGlobal 1\n0013 Pop\n",
+			constants:    []interface{}{1, 2},
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpConstant 1\n0010 OpSetGlobal 1\n0013 OpPop\n",
 		},
 		{
 			input: `
@@ -263,7 +316,7 @@ func TestGlobalBindExpressions(t *testing.T) {
             one;
             `,
 			constants:    []interface{}{1},
-			instructions: "0000 LoadConstant 0\n0003 BindGlobal 0\n0006 Pop\n0007 LoadGlobal 0\n0010 Pop\n",
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpGetGlobal 0\n0010 OpPop\n",
 		},
 		{
 			input: `
@@ -272,7 +325,7 @@ func TestGlobalBindExpressions(t *testing.T) {
             two;
             `,
 			constants:    []interface{}{1},
-			instructions: "0000 LoadConstant 0\n0003 BindGlobal 0\n0006 Pop\n0007 LoadGlobal 0\n0010 BindGlobal 1\n0013 Pop\n0014 LoadGlobal 1\n0017 Pop\n",
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpGetGlobal 0\n0010 OpSetGlobal 1\n0013 OpPop\n0014 OpGetGlobal 1\n0017 OpPop\n",
 		},
 	}
 
@@ -490,31 +543,20 @@ func TestFunctionsWithoutReturn(t *testing.T) {
 }
 
 func TestClosures(t *testing.T) {
-	tests := []compilerTestCase{
+	tests := []compilerTestCase2{
 		{
-			input: `fn(a) { 
-				return fn(b) {
-					return a + b
-				}
-			}
-			`,
-			expectedConstants: []interface{}{
-				[]code.Instructions{
-					code.Make(code.OpGetFree, 0),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpAdd),
-					code.Make(code.OpReturn),
-				},
-				[]code.Instructions{
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpClosure, 0, 1),
-					code.Make(code.OpReturn),
-				},
-			},
-			expectedInstructions: []code.Instructions{
-				code.Make(code.OpClosure, 1, 0),
-				code.Make(code.OpPop),
+			input: `
+            fn(a) {
+                return fn(b) {
+                    return a + b
+                }
+            }
+            `,
+			constants: []interface{}{
+				Instructions("0000 OpGetFree 0\n0002 OpGetLocal 0\n0004 OpAdd\n0005 OpReturn\n"),
+				Instructions("0000 OpGetLocal 0\n0002 OpClosure 0 1\n0006 OpReturn\n"),
 			},
+			instructions: "0000 OpClosure 1 0\n0004 OpPop\n",
 		},
 		{
 			input: `
@@ -526,93 +568,45 @@ func TestClosures(t *testing.T) {
                 }
             };
             `,
-			expectedConstants: []interface{}{
-				[]code.Instructions{
-					code.Make(code.OpGetFree, 0),
-					code.Make(code.OpGetFree, 1),
-					code.Make(code.OpAdd),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpAdd),
-					code.Make(code.OpReturn),
-				},
-				[]code.Instructions{
-					code.Make(code.OpGetFree, 0),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpClosure, 0, 2),
-					code.Make(code.OpReturn),
-				},
-				[]code.Instructions{
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpClosure, 1, 1),
-					code.Make(code.OpReturn),
-				},
-			},
-			expectedInstructions: []code.Instructions{
-				code.Make(code.OpClosure, 2, 0),
-				code.Make(code.OpPop),
+			constants: []interface{}{
+				Instructions("0000 OpGetFree 0\n0002 OpGetFree 1\n0004 OpAdd\n0005 OpGetLocal 0\n0007 OpAdd\n0008 OpReturn\n"),
+				Instructions("0000 OpGetFree 0\n0002 OpGetLocal 0\n0004 OpClosure 0 2\n0008 OpReturn\n"),
+				Instructions("0000 OpGetLocal 0\n0002 OpClosure 1 1\n0006 OpReturn\n"),
 			},
+			instructions: "0000 OpClosure 2 0\n0004 OpPop\n",
 		},
 		{
 			input: `
-            let global = 55;
+			global := 55;
 
             fn() {
-                let a = 66;
+				a := 66;
 
                 return fn() {
-                    let b = 77;
+					b := 77;
 
                     return fn() {
-                        let c = 88;
+						c := 88;
 
                         return global + a + b + c;
                     }
                 }
             }
             `,
-			expectedConstants: []interface{}{
+			constants: []interface{}{
 				55,
 				66,
 				77,
 				88,
-				[]code.Instructions{
-					code.Make(code.OpConstant, 3),
-					code.Make(code.OpSetLocal, 0),
-					code.Make(code.OpGetGlobal, 0),
-					code.Make(code.OpGetFree, 0),
-					code.Make(code.OpAdd),
-					code.Make(code.OpGetFree, 1),
-					code.Make(code.OpAdd),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpAdd),
-					code.Make(code.OpReturn),
-				},
-				[]code.Instructions{
-					code.Make(code.OpConstant, 2),
-					code.Make(code.OpSetLocal, 0),
-					code.Make(code.OpGetFree, 0),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpClosure, 4, 2),
-					code.Make(code.OpReturn),
-				},
-				[]code.Instructions{
-					code.Make(code.OpConstant, 1),
-					code.Make(code.OpSetLocal, 0),
-					code.Make(code.OpGetLocal, 0),
-					code.Make(code.OpClosure, 5, 1),
-					code.Make(code.OpReturn),
-				},
-			},
-			expectedInstructions: []code.Instructions{
-				code.Make(code.OpConstant, 0),
-				code.Make(code.OpSetGlobal, 0),
-				code.Make(code.OpClosure, 6, 0),
-				code.Make(code.OpPop),
+				Instructions("0000 OpConstant 3\n0003 OpSetLocal 0\n0005 OpPop\n0006 OpGetGlobal 0\n0009 OpGetFree 0\n0011 OpAdd\n0012 OpGetFree 1\n0014 OpAdd\n0015 OpGetLocal 0\n0017 OpAdd\n0018 OpReturn\n"),
+				Instructions("0000 OpConstant 2\n0003 OpSetLocal 0\n0005 OpPop\n0006 OpGetFree 0\n0008 OpGetLocal 0\n0010 OpClosure 4 2\n0014 OpReturn\n"),
+				Instructions("0000 OpConstant 1\n0003 OpSetLocal 0\n0005 OpPop\n0006 OpGetLocal 0\n0008 OpClosure 5 1\n0012 OpReturn\n"),
 			},
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpClosure 6 0\n0011 OpPop\n",
 		},
 	}
 
-	runCompilerTests(t, tests)
+	runCompilerTests2(t, tests)
 }
 
 func TestCompilerScopes(t *testing.T) {
@@ -667,9 +661,9 @@ func TestFunctionCalls(t *testing.T) {
 			input: `fn() { return 24 }();`,
 			constants: []interface{}{
 				24,
-				Instructions("0000 LoadConstant 0\n0003 Return\n"),
+				Instructions("0000 OpConstant 0\n0003 OpReturn\n"),
 			},
-			instructions: "0000 MakeClosure 1 0\n0004 Call 0\n0006 Pop\n",
+			instructions: "0000 OpClosure 1 0\n0004 OpCall 0\n0006 OpPop\n",
 		},
 		{
 			input: `
@@ -678,9 +672,9 @@ func TestFunctionCalls(t *testing.T) {
             `,
 			constants: []interface{}{
 				24,
-				Instructions("0000 SetSelf 0\n0002 LoadConstant 0\n0005 Return\n"),
+				Instructions("0000 OpConstant 0\n0003 OpReturn\n"),
 			},
-			instructions: "0000 LoadGlobal 0\n0003 MakeClosure 1 1\n0007 BindGlobal 0\n0010 Pop\n0011 LoadGlobal 0\n0014 Call 0\n0016 Pop\n",
+			instructions: "0000 OpClosure 1 0\n0004 OpSetGlobal 0\n0007 OpPop\n0008 OpGetGlobal 0\n0011 OpCall 0\n0013 OpPop\n",
 		},
 		{
 			input: `
@@ -688,10 +682,10 @@ func TestFunctionCalls(t *testing.T) {
             oneArg(24);
             `,
 			constants: []interface{}{
-				Instructions("0000 SetSelf 0\n0002 LoadLocal 0\n0004 Return\n"),
+				Instructions("0000 OpGetLocal 0\n0002 OpReturn\n"),
 				24,
 			},
-			instructions: "0000 LoadGlobal 0\n0003 MakeClosure 0 1\n0007 BindGlobal 0\n0010 Pop\n0011 LoadGlobal 0\n0014 LoadConstant 1\n0017 Call 1\n0019 Pop\n",
+			instructions: "0000 OpClosure 0 0\n0004 OpSetGlobal 0\n0007 OpPop\n0008 OpGetGlobal 0\n0011 OpConstant 1\n0014 OpCall 1\n0016 OpPop\n",
 		},
 		{
 			input: `
@@ -699,12 +693,12 @@ func TestFunctionCalls(t *testing.T) {
             manyArg(24, 25, 26);
             `,
 			constants: []interface{}{
-				Instructions("0000 SetSelf 0\n0002 LoadLocal 0\n0004 Pop\n0005 LoadLocal 1\n0007 Pop\n0008 LoadLocal 2\n0010 Return\n"),
+				Instructions("0000 OpGetLocal 0\n0002 OpPop\n0003 OpGetLocal 1\n0005 OpPop\n0006 OpGetLocal 2\n0008 OpReturn\n"),
 				24,
 				25,
 				26,
 			},
-			instructions: "0000 LoadGlobal 0\n0003 MakeClosure 0 1\n0007 BindGlobal 0\n0010 Pop\n0011 LoadGlobal 0\n0014 LoadConstant 1\n0017 LoadConstant 2\n0020 LoadConstant 3\n0023 Call 3\n0025 Pop\n",
+			instructions: "0000 OpClosure 0 0\n0004 OpSetGlobal 0\n0007 OpPop\n0008 OpGetGlobal 0\n0011 OpConstant 1\n0014 OpConstant 2\n0017 OpConstant 3\n0020 OpCall 3\n0022 OpPop\n",
 		},
 	}
 
@@ -715,11 +709,11 @@ func TestAssignmentExpressions(t *testing.T) {
 	tests := []compilerTestCase2{
 		{
 			input: `
-			let x = 1
+			x := 1
 			x = 2
 			`,
 			constants:    []interface{}{1, 2},
-			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpConstant 1\n0009 OpAssignGlobal 0\n0012 OpPop\n",
+			instructions: "0000 OpConstant 0\n0003 OpSetGlobal 0\n0006 OpPop\n0007 OpConstant 1\n0010 OpAssignGlobal 0\n0013 OpPop\n",
 		},
 	}
 
@@ -730,7 +724,7 @@ func TestAssignmentStatementScopes(t *testing.T) {
 	tests := []compilerTestCase{
 		{
 			input: `
-            let num = 0;
+            num := 0;
             fn() { num  = 55; }
             `,
 			expectedConstants: []interface{}{
@@ -746,13 +740,14 @@ func TestAssignmentStatementScopes(t *testing.T) {
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpConstant, 0),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 				code.Make(code.OpClosure, 2, 0),
 				code.Make(code.OpPop),
 			},
 		},
 		{
 			input: `
-            fn() { let num = 0; num  = 55; }
+            fn() { num := 0; num  = 55; }
             `,
 			expectedConstants: []interface{}{
 				0,
@@ -760,6 +755,7 @@ func TestAssignmentStatementScopes(t *testing.T) {
 				[]code.Instructions{
 					code.Make(code.OpConstant, 0),
 					code.Make(code.OpSetLocal, 0),
+					code.Make(code.OpPop),
 					code.Make(code.OpConstant, 1),
 					code.Make(code.OpAssignLocal, 0),
 					code.Make(code.OpNull),
@@ -780,7 +776,7 @@ func TestLetStatementScopes(t *testing.T) {
 	tests := []compilerTestCase{
 		{
 			input: `
-            let num = 55;
+            num := 55;
             fn() { return num }
             `,
 			expectedConstants: []interface{}{
@@ -793,6 +789,7 @@ func TestLetStatementScopes(t *testing.T) {
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpConstant, 0),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 				code.Make(code.OpClosure, 1, 0),
 				code.Make(code.OpPop),
 			},
@@ -800,7 +797,7 @@ func TestLetStatementScopes(t *testing.T) {
 		{
 			input: `
             fn() {
-                let num = 55;
+                num := 55;
                 return num
             }
             `,
@@ -809,6 +806,7 @@ func TestLetStatementScopes(t *testing.T) {
 				[]code.Instructions{
 					code.Make(code.OpConstant, 0),
 					code.Make(code.OpSetLocal, 0),
+					code.Make(code.OpPop),
 					code.Make(code.OpGetLocal, 0),
 					code.Make(code.OpReturn),
 				},
@@ -821,8 +819,8 @@ func TestLetStatementScopes(t *testing.T) {
 		{
 			input: `
             fn() {
-                let a = 55;
-                let b = 77;
+                a := 55;
+                b := 77;
                 return a + b
             }
             `,
@@ -832,8 +830,10 @@ func TestLetStatementScopes(t *testing.T) {
 				[]code.Instructions{
 					code.Make(code.OpConstant, 0),
 					code.Make(code.OpSetLocal, 0),
+					code.Make(code.OpPop),
 					code.Make(code.OpConstant, 1),
 					code.Make(code.OpSetLocal, 1),
+					code.Make(code.OpPop),
 					code.Make(code.OpGetLocal, 0),
 					code.Make(code.OpGetLocal, 1),
 					code.Make(code.OpAdd),
@@ -847,8 +847,8 @@ func TestLetStatementScopes(t *testing.T) {
 		},
 		{
 			input: `
-			let a = 0;
-			let a = a + 1;
+			a := 0;
+			a := a + 1;
 			`,
 			expectedConstants: []interface{}{
 				0,
@@ -857,10 +857,12 @@ func TestLetStatementScopes(t *testing.T) {
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpConstant, 0),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 				code.Make(code.OpGetGlobal, 0),
 				code.Make(code.OpConstant, 1),
 				code.Make(code.OpAdd),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 			},
 		},
 	}
@@ -912,7 +914,7 @@ func TestRecursiveFunctions(t *testing.T) {
 	tests := []compilerTestCase{
 		{
 			input: `
-           let countDown = fn(x) { return countDown(x - 1); };
+           countDown := fn(x) { return countDown(x - 1); };
            countDown(1);
            `,
 			expectedConstants: []interface{}{
@@ -930,6 +932,7 @@ func TestRecursiveFunctions(t *testing.T) {
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpClosure, 1, 0),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 				code.Make(code.OpGetGlobal, 0),
 				code.Make(code.OpConstant, 2),
 				code.Make(code.OpCall, 1),
@@ -938,8 +941,8 @@ func TestRecursiveFunctions(t *testing.T) {
 		},
 		{
 			input: `
-           let wrapper = fn() {
-               let countDown = fn(x) { return countDown(x - 1); };
+           wrapper := fn() {
+               countDown := fn(x) { return countDown(x - 1); };
                return countDown(1);
            };
            wrapper();
@@ -958,6 +961,7 @@ func TestRecursiveFunctions(t *testing.T) {
 				[]code.Instructions{
 					code.Make(code.OpClosure, 1, 0),
 					code.Make(code.OpSetLocal, 0),
+					code.Make(code.OpPop),
 					code.Make(code.OpGetLocal, 0),
 					code.Make(code.OpConstant, 2),
 					code.Make(code.OpCall, 1),
@@ -967,6 +971,7 @@ func TestRecursiveFunctions(t *testing.T) {
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpClosure, 3, 0),
 				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpPop),
 				code.Make(code.OpGetGlobal, 0),
 				code.Make(code.OpCall, 0),
 				code.Make(code.OpPop),
diff --git a/evaluator/evaluator.go b/evaluator/evaluator.go
index abf9725..9e7aa37 100644
--- a/evaluator/evaluator.go
+++ b/evaluator/evaluator.go
@@ -256,15 +256,22 @@ func nativeBoolToBooleanObject(input bool) object.Object {
 func evalPrefixExpression(operator string, right object.Object) object.Object {
 	switch operator {
 	case "!":
-		return evalBangOperatorExpression(right)
-	case "-":
-		return evalMinusPrefixOperatorExpression(right)
+		if right.Type() == object.BOOLEAN_OBJ {
+			return evalBooleanPrefixOperatorExpression(operator, right)
+		}
+		return evalIntegerPrefixOperatorExpression(operator, right)
+	case "~", "-":
+		return evalIntegerPrefixOperatorExpression(operator, right)
 	default:
 		return newError("unknown operator: %s%s", operator, right.Type())
 	}
 }
 
-func evalBangOperatorExpression(right object.Object) object.Object {
+func evalBooleanPrefixOperatorExpression(operator string, right object.Object) object.Object {
+	if right.Type() != object.BOOLEAN_OBJ {
+		return newError("unknown operator: %s%s", operator, right.Type())
+	}
+
 	switch right {
 	case TRUE:
 		return FALSE
@@ -277,17 +284,28 @@ func evalBangOperatorExpression(right object.Object) object.Object {
 	}
 }
 
-func evalMinusPrefixOperatorExpression(right object.Object) object.Object {
+func evalIntegerPrefixOperatorExpression(operator string, right object.Object) object.Object {
 	if right.Type() != object.INTEGER_OBJ {
 		return newError("unknown operator: -%s", right.Type())
 	}
 
 	value := right.(*object.Integer).Value
-	return &object.Integer{Value: -value}
+	switch operator {
+	case "!":
+		return FALSE
+	case "~":
+		return &object.Integer{Value: ^value}
+	case "-":
+		return &object.Integer{Value: -value}
+	default:
+		return newError("unknown operator: %s", operator)
+	}
 }
 
 func evalInfixExpression(operator string, left, right object.Object) object.Object {
 	switch {
+	case left.Type() == object.BOOLEAN_OBJ && right.Type() == object.BOOLEAN_OBJ:
+		return evalBooleanInfixExpression(operator, left, right)
 	case left.Type() == object.INTEGER_OBJ && right.Type() == object.INTEGER_OBJ:
 		return evalIntegerInfixExpression(operator, left, right)
 	case left.Type() == object.STRING_OBJ && right.Type() == object.STRING_OBJ:
@@ -303,6 +321,24 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 	}
 }
 
+func evalBooleanInfixExpression(operator string, left, right object.Object) object.Object {
+	leftVal := left.(*object.Boolean).Value
+	rightVal := right.(*object.Boolean).Value
+
+	switch operator {
+	case "==":
+		return nativeBoolToBooleanObject(left == right)
+	case "!=":
+		return nativeBoolToBooleanObject(leftVal != rightVal)
+	case "&&":
+		return &object.Boolean{Value: leftVal && rightVal}
+	case "||":
+		return &object.Boolean{Value: leftVal || rightVal}
+	default:
+		return newError("unknown operator: %s %s %s", left.Type(), operator, right.Type())
+	}
+}
+
 func evalStringInfixExpression(operator string, left object.Object, right object.Object) object.Object {
 	leftVal := left.(*object.String).Value
 	rightVal := right.(*object.String).Value
@@ -338,6 +374,12 @@ func evalIntegerInfixExpression(operator string, left, right object.Object) obje
 		return &object.Integer{Value: leftVal / rightVal}
 	case "%":
 		return &object.Integer{Value: leftVal % rightVal}
+	case "|":
+		return &object.Integer{Value: leftVal | rightVal}
+	case "^":
+		return &object.Integer{Value: leftVal ^ rightVal}
+	case "&":
+		return &object.Integer{Value: leftVal & rightVal}
 	case "<":
 		return nativeBoolToBooleanObject(leftVal < rightVal)
 	case "<=":
diff --git a/evaluator/evaluator_test.go b/evaluator/evaluator_test.go
index a5fad86..c47767a 100644
--- a/evaluator/evaluator_test.go
+++ b/evaluator/evaluator_test.go
@@ -13,7 +13,7 @@ import (
 func TestEvalIntegerExpression(t *testing.T) {
 	tests := []struct {
 		input    string
-		expected int64
+		expected interface{}
 	}{
 		{"5", 5},
 		{"10", 10},
@@ -30,12 +30,21 @@ func TestEvalIntegerExpression(t *testing.T) {
 		{"3 * 3 * 3 + 10", 37},
 		{"3 * (3 * 3) + 10", 37},
 		{"(5 + 10 * 2 + 15 / 3) * 2 + -10", 50},
+		{"!1", false},
+		{"~1", -2},
 		{"5 % 2", 1},
+		{"1 | 2", 3},
+		{"2 ^ 4", 6},
+		{"3 & 6", 2},
 	}
 
 	for _, tt := range tests {
 		evaluated := testEval(tt.input)
-		testIntegerObject(t, evaluated, tt.expected)
+		if expected, ok := tt.expected.(int64); ok {
+			testIntegerObject(t, evaluated, expected)
+		} else if expected, ok := tt.expected.(bool); ok {
+			testBooleanObject(t, evaluated, expected)
+		}
 	}
 }
 
@@ -46,6 +55,16 @@ func TestEvalBooleanExpression(t *testing.T) {
 	}{
 		{"true", true},
 		{"false", false},
+		{"!true", false},
+		{"!false", true},
+		{"true && true", true},
+		{"false && true", false},
+		{"true && false", false},
+		{"false && false", false},
+		{"true || true", true},
+		{"false || true", true},
+		{"true || false", true},
+		{"false || false", false},
 		{"1 < 2", true},
 		{"1 > 2", false},
 		{"1 < 1", false},
@@ -78,25 +97,6 @@ func TestEvalBooleanExpression(t *testing.T) {
 	}
 }
 
-func TestBangOperator(t *testing.T) {
-	tests := []struct {
-		input    string
-		expected bool
-	}{
-		{"!true", false},
-		{"!false", true},
-		{"!5", false},
-		{"!!true", true},
-		{"!!false", false},
-		{"!!5", true},
-	}
-
-	for _, tt := range tests {
-		evaluated := testEval(tt.input)
-		testBooleanObject(t, evaluated, tt.expected)
-	}
-}
-
 func TestIfElseExpression(t *testing.T) {
 	tests := []struct {
 		input    string
diff --git a/examples/fizzbuzz.monkey b/examples/fizzbuzz.monkey
new file mode 100644
index 0000000..1218a91
--- /dev/null
+++ b/examples/fizzbuzz.monkey
@@ -0,0 +1,19 @@
+#!./monkey-lang
+
+test := fn(n) {
+  if (n % 15 == 0) {
+    return "FizzBuzz"
+  } else if (n % 5 == 0) {
+    return "Buzz"
+  } else if (n % 3 == 0) {
+    return "Fizz"
+  } else {
+    return str(n)
+  }
+}
+
+n := 1
+while (n <= 100) {
+  print(test(n))
+  n = n + 1
+}
\ No newline at end of file
diff --git a/lexer/lexer.go b/lexer/lexer.go
index 6ee2eca..80cb710 100644
--- a/lexer/lexer.go
+++ b/lexer/lexer.go
@@ -74,7 +74,7 @@ func (l *Lexer) NextToken() token.Token {
 				Literal: literal,
 			}
 		} else {
-			tok = newToken(token.BANG, l.ch)
+			tok = newToken(token.NOT, l.ch)
 		}
 
 	case '/':
@@ -83,12 +83,34 @@ func (l *Lexer) NextToken() token.Token {
 			tok.Type = token.COMMENT
 			tok.Literal = l.readLine()
 		} else {
-			tok = newToken(token.SLASH, l.ch)
+			tok = newToken(token.DIVIDE, l.ch)
 		}
 	case '*':
-		tok = newToken(token.ASTERISK, l.ch)
+		tok = newToken(token.MULTIPLY, l.ch)
 	case '%':
-		tok = newToken(token.PERCENT, l.ch)
+		tok = newToken(token.MODULO, l.ch)
+	case '&':
+		if l.peekChar() == '&' {
+			ch := l.ch
+			l.readChar()
+			literal := string(ch) + string(l.ch)
+			tok = token.Token{Type: token.AND, Literal: literal}
+		} else {
+			tok = newToken(token.BITWISE_AND, l.ch)
+		}
+	case '|':
+		if l.peekChar() == '|' {
+			ch := l.ch
+			l.readChar()
+			literal := string(ch) + string(l.ch)
+			tok = token.Token{Type: token.OR, Literal: literal}
+		} else {
+			tok = newToken(token.BITWISE_OR, l.ch)
+		}
+	case '^':
+		tok = newToken(token.BITWISE_XOR, l.ch)
+	case '~':
+		tok = newToken(token.BITWISE_NOT, l.ch)
 	case '<':
 		if l.peekChar() == '=' {
 			l.readChar()
diff --git a/lexer/lexer_test.go b/lexer/lexer_test.go
index 2283bc9..1be85df 100644
--- a/lexer/lexer_test.go
+++ b/lexer/lexer_test.go
@@ -33,6 +33,8 @@ func TestNextToken(t *testing.T) {
 				[1, 2];
 				{"foo": "bar"}
 				d.foo
+				&|^~
+				!&&||
 			`
 
 	tests := []struct {
@@ -74,10 +76,10 @@ func TestNextToken(t *testing.T) {
 		{token.RPAREN, ")"},
 		{token.SEMICOLON, ";"},
 
-		{token.BANG, "!"},
+		{token.NOT, "!"},
 		{token.MINUS, "-"},
-		{token.SLASH, "/"},
-		{token.ASTERISK, "*"},
+		{token.DIVIDE, "/"},
+		{token.MULTIPLY, "*"},
 		{token.INT, "5"},
 		{token.SEMICOLON, ";"},
 		{token.INT, "5"},
@@ -137,6 +139,13 @@ func TestNextToken(t *testing.T) {
 		{token.IDENT, "d"},
 		{token.DOT, "."},
 		{token.IDENT, "foo"},
+		{token.BitwiseAND, "&"},
+		{token.BitwiseOR, "|"},
+		{token.BitwiseXOR, "^"},
+		{token.BitwiseNOT, "~"},
+		{token.NOT, "!"},
+		{token.AND, "&&"},
+		{token.OR, "||"},
 		{token.EOF, ""},
 	}
 
diff --git a/parser/parser.go b/parser/parser.go
index d09a804..52f6d01 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -11,9 +11,15 @@ import (
 const (
 	_ int = iota
 	LOWEST
+	OR
+	AND
+	NOT
 	ASSIGN      // := or =
 	EQUALS      // ==
 	LESSGREATER // > or <
+	BITWISE_OR  // |
+	BITWISE_XOR // ^
+	BITWISE_AND // &
 	SUM         // + or -
 	PRODUCT     // * or / or %
 	PREFIX      // -X or !X
@@ -22,22 +28,28 @@ const (
 )
 
 var precedences = map[token.TokenType]int{
-	token.BIND:     ASSIGN,
-	token.ASSIGN:   ASSIGN,
-	token.EQ:       EQUALS,
-	token.NOT_EQ:   EQUALS,
-	token.LT:       LESSGREATER,
-	token.GT:       LESSGREATER,
-	token.LTE:      LESSGREATER,
-	token.GTE:      LESSGREATER,
-	token.PLUS:     SUM,
-	token.MINUS:    SUM,
-	token.SLASH:    PRODUCT,
-	token.ASTERISK: PRODUCT,
-	token.PERCENT:  PRODUCT,
-	token.LPAREN:   CALL,
-	token.LBRACKET: INDEX,
-	token.DOT:      INDEX,
+	token.OR:          OR,
+	token.AND:         AND,
+	token.NOT:         NOT,
+	token.BIND:        ASSIGN,
+	token.ASSIGN:      ASSIGN,
+	token.EQ:          EQUALS,
+	token.NOT_EQ:      EQUALS,
+	token.LT:          LESSGREATER,
+	token.GT:          LESSGREATER,
+	token.LTE:         LESSGREATER,
+	token.GTE:         LESSGREATER,
+	token.BITWISE_OR:  BITWISE_OR,
+	token.BITWISE_XOR: BITWISE_XOR,
+	token.BITWISE_AND: BITWISE_AND,
+	token.PLUS:        SUM,
+	token.MINUS:       SUM,
+	token.DIVIDE:      PRODUCT,
+	token.MULTIPLY:    PRODUCT,
+	token.MODULO:      PRODUCT,
+	token.LPAREN:      CALL,
+	token.LBRACKET:    INDEX,
+	token.DOT:         INDEX,
 }
 
 type (
@@ -65,7 +77,6 @@ func New(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.BANG, p.parsePrefixExpression)
 	p.registerPrefix(token.MINUS, p.parsePrefixExpression)
 	p.registerPrefix(token.TRUE, p.parseBoolean)
 	p.registerPrefix(token.FALSE, p.parseBoolean)
@@ -81,9 +92,9 @@ func New(l *lexer.Lexer) *Parser {
 	p.infixParseFns = make(map[token.TokenType]infixParseFn)
 	p.registerInfix(token.PLUS, p.parseInfixExpression)
 	p.registerInfix(token.MINUS, p.parseInfixExpression)
-	p.registerInfix(token.SLASH, p.parseInfixExpression)
-	p.registerInfix(token.ASTERISK, p.parseInfixExpression)
-	p.registerInfix(token.PERCENT, p.parseInfixExpression)
+	p.registerInfix(token.DIVIDE, p.parseInfixExpression)
+	p.registerInfix(token.MULTIPLY, p.parseInfixExpression)
+	p.registerInfix(token.MODULO, p.parseInfixExpression)
 	p.registerInfix(token.EQ, p.parseInfixExpression)
 	p.registerInfix(token.NOT_EQ, p.parseInfixExpression)
 	p.registerInfix(token.LT, p.parseInfixExpression)
@@ -96,6 +107,15 @@ func New(l *lexer.Lexer) *Parser {
 	p.registerInfix(token.ASSIGN, p.parseAssignmentExpression)
 	p.registerInfix(token.DOT, p.parseSelectorExpression)
 
+	p.registerPrefix(token.BITWISE_NOT, p.parsePrefixExpression)
+	p.registerInfix(token.BITWISE_OR, p.parseInfixExpression)
+	p.registerInfix(token.BITWISE_XOR, p.parseInfixExpression)
+	p.registerInfix(token.BITWISE_AND, p.parseInfixExpression)
+
+	p.registerPrefix(token.NOT, p.parsePrefixExpression)
+	p.registerInfix(token.OR, p.parseInfixExpression)
+	p.registerInfix(token.AND, p.parseInfixExpression)
+
 	// Read two tokens, so curToken and peekToken are both set
 	p.nextToken()
 	p.nextToken()
diff --git a/parser/parser_test.go b/parser/parser_test.go
index da05cb5..9e5f60c 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -138,6 +138,7 @@ func TestParsingPrefixExpressions(t *testing.T) {
 		{"-foobar;", "-", "foobar"},
 		{"!true;", "!", true},
 		{"!false;", "!", false},
+		{"~5;", "~", 5},
 	}
 
 	for _, tt := range prefixTests {
diff --git a/token/token.go b/token/token.go
index f5f269f..4b36d9f 100644
--- a/token/token.go
+++ b/token/token.go
@@ -24,10 +24,31 @@ const (
 	ASSIGN   = "="
 	PLUS     = "+"
 	MINUS    = "-"
-	BANG     = "!"
-	ASTERISK = "*"
-	SLASH    = "/"
-	PERCENT  = "%"
+	MULTIPLY = "*"
+	DIVIDE   = "/"
+	MODULO   = "%"
+
+	// Bitwise / Logical operators
+
+	// BITWISE_AND AND
+	BITWISE_AND = "&"
+	// BITWISE_OR OR
+	BITWISE_OR = "|"
+	// BITWISE_XOR XOR
+	BITWISE_XOR = "^"
+	// BITWISE_NOT NOT
+	BITWISE_NOT = "~"
+
+	//
+	// Comparision operators
+	//
+
+	// NOT the not operator
+	NOT = "!"
+	// AND the and operator
+	AND = "&&"
+	// OR the or operator
+	OR = "||"
 
 	LT  = "<"
 	LTE = "<="
diff --git a/vm/vm.go b/vm/vm.go
index 5e01216..8828bcb 100644
--- a/vm/vm.go
+++ b/vm/vm.go
@@ -112,7 +112,8 @@ func (vm *VM) Run() error {
 				return err
 			}
 
-		case code.OpAdd, code.OpSub, code.OpMul, code.OpDiv, code.OpMod:
+		case code.OpAdd, code.OpSub, code.OpMul, code.OpDiv, code.OpMod, code.OpOr,
+			code.OpAnd, code.OpBitwiseOR, code.OpBitwiseXOR, code.OpBitwiseAND:
 			err := vm.executeBinaryOperation(op)
 			if err != nil {
 				return err
@@ -139,8 +140,14 @@ func (vm *VM) Run() error {
 				return err
 			}
 
-		case code.OpBang:
-			err := vm.executeBangOperator()
+		case code.OpNot:
+			err := vm.executeNotOperator()
+			if err != nil {
+				return err
+			}
+
+		case code.OpBitwiseNOT:
+			err := vm.executeBitwiseNotOperator()
 			if err != nil {
 				return err
 			}
@@ -516,18 +523,38 @@ func (vm *VM) executeBinaryOperation(op code.Opcode) error {
 	left := vm.pop()
 
 	leftType := left.Type()
-	rightRight := right.Type()
+	rightType := right.Type()
 
 	switch {
-	case leftType == object.INTEGER_OBJ && rightRight == object.INTEGER_OBJ:
+	case leftType == object.BOOLEAN_OBJ && rightType == object.BOOLEAN_OBJ:
+		return vm.executeBinaryBooleanOperation(op, left, right)
+	case leftType == object.INTEGER_OBJ && rightType == object.INTEGER_OBJ:
 		return vm.executeBinaryIntegerOperation(op, left, right)
-	case leftType == object.STRING_OBJ && rightRight == object.STRING_OBJ:
+	case leftType == object.STRING_OBJ && rightType == object.STRING_OBJ:
 		return vm.executeBinaryStringOperation(op, left, right)
 	default:
-		return fmt.Errorf("unsupported types for binary operation: %s %s", leftType, rightRight)
+		return fmt.Errorf("unsupported types for binary operation: %s %s", leftType, rightType)
 	}
 }
 
+func (vm *VM) executeBinaryBooleanOperation(op code.Opcode, left, right object.Object) error {
+	leftValue := left.(*object.Boolean).Value
+	rightValue := right.(*object.Boolean).Value
+
+	var result bool
+
+	switch op {
+	case code.OpOr:
+		result = leftValue || rightValue
+	case code.OpAnd:
+		result = leftValue && rightValue
+	default:
+		return fmt.Errorf("unknown boolean operator: %d", op)
+	}
+
+	return vm.push(&object.Boolean{Value: result})
+}
+
 func (vm *VM) executeBinaryIntegerOperation(op code.Opcode, left, right object.Object) error {
 	leftValue := left.(*object.Integer).Value
 	rightValue := right.(*object.Integer).Value
@@ -545,6 +572,12 @@ func (vm *VM) executeBinaryIntegerOperation(op code.Opcode, left, right object.O
 		result = leftValue / rightValue
 	case code.OpMod:
 		result = leftValue % rightValue
+	case code.OpBitwiseOR:
+		result = leftValue | rightValue
+	case code.OpBitwiseXOR:
+		result = leftValue ^ rightValue
+	case code.OpBitwiseAND:
+		result = leftValue & rightValue
 
 	default:
 		return fmt.Errorf("unknown integer operator: %d", op)
@@ -604,7 +637,15 @@ func (vm *VM) executeIntegerComparison(op code.Opcode, left, right object.Object
 	}
 }
 
-func (vm *VM) executeBangOperator() error {
+func (vm *VM) executeBitwiseNotOperator() error {
+	operand := vm.pop()
+	if i, ok := operand.(*object.Integer); ok {
+		return vm.push(&object.Integer{Value: ^i.Value})
+	}
+	return fmt.Errorf("expected int got=%T", operand)
+}
+
+func (vm *VM) executeNotOperator() error {
 	operand := vm.pop()
 
 	switch operand {
@@ -622,12 +663,11 @@ func (vm *VM) executeBangOperator() error {
 func (vm *VM) executeMinusOperator() error {
 	operand := vm.pop()
 
-	if operand.Type() != object.INTEGER_OBJ {
-		return fmt.Errorf("unsupported type for negation: %s", operand.Type())
+	if i, ok := operand.(*object.Integer); ok {
+		return vm.push(&object.Integer{Value: -i.Value})
 	}
 
-	value := operand.(*object.Integer).Value
-	return vm.push(&object.Integer{Value: -value})
+	return fmt.Errorf("expected int got=%T", operand)
 }
 
 func (vm *VM) executeCall(numArgs int) error {
diff --git a/vm/vm_test.go b/vm/vm_test.go
index b992267..831972a 100644
--- a/vm/vm_test.go
+++ b/vm/vm_test.go
@@ -224,7 +224,12 @@ func TestIntegerArithmetic(t *testing.T) {
 		{"-10", -10},
 		{"-50 + 100 + -50", 0},
 		{"(5 + 10 * 2 + 15 / 3) * 2 + -10", 50},
+		{"!1", false},
+		{"~1", -2},
 		{"5 % 2", 1},
+		{"1 | 2", 3},
+		{"2 ^ 4", 6},
+		{"3 & 6", 2},
 	}
 
 	runVmTests(t, tests)
@@ -237,6 +242,37 @@ func TestBooleanExpressions(t *testing.T) {
 		{"null", nil},
 		{"!true", false},
 		{"!false", true},
+		{"true && true", true},
+		{"false && true", false},
+		{"true && false", false},
+		{"false && false", false},
+		{"true || true", true},
+		{"false || true", true},
+		{"true || false", true},
+		{"false || false", false},
+		{"1 < 2", true},
+		{"1 > 2", false},
+		{"1 < 1", false},
+		{"1 > 1", false},
+		{"1 == 1", true},
+		{"1 != 1", false},
+		{"1 == 2", false},
+		{"1 != 2", true},
+		{"true == true", true},
+		{"false == false", true},
+		{"true == false", false},
+		{"true != false", true},
+		{"false != true", true},
+		{"(1 < 2) == true", true},
+		{"(1 < 2) == false", false},
+		{"(1 > 2) == true", false},
+		{"(1 > 2) == false", true},
+		{"(1 <= 2) == true", true},
+		{"(1 <= 2) == false", false},
+		{"(1 >= 2) == true", false},
+		{"(1 >= 2) == false", true},
+		{"!true", false},
+		{"!false", true},
 		{"!5", false},
 		{"!!true", true},
 		{"!!false", false},