Switched to pointer receivers for values

src/core/CompileAssign.go

@@ -36,9 +36,9 @@ func (f *Function) CompileAssign(node *ast.Assign) error {
 	operation := node.Expression.Token
 
 	switch leftValue := leftValue.(type) {
-	case eval.Register:
+	case *eval.Register:
 		f.Execute(operation, leftValue.Register, right)
-	case eval.Memory:
+	case *eval.Memory:
 		if operation.Kind == token.Assign {
 			rightValue, err := f.Evaluate(right)
 

src/core/CompileAssignDivision.go

@@ -75,11 +75,11 @@ func (f *Function) CompileAssignDivision(expr *expression.Expression) error {
 	divisor := division.Children[1]
 
 	switch dividend := dividend.(type) {
-	case eval.Number:
+	case *eval.Number:
 		f.SaveRegister(x86.RAX)
 		f.RegisterNumber(asm.MOVE, x86.RAX, dividend.Number)
 		err = f.Execute(division.Token, x86.RAX, divisor)
-	case eval.Register:
+	case *eval.Register:
 		if dividend.Register != quotientVariable.Value.Register && dividend.IsAlive() {
 			tmp := f.NewRegister()
 			f.RegisterRegister(asm.MOVE, tmp, dividend.Register)

src/core/CompileCondition.go

@@ -80,11 +80,11 @@ func (f *Function) CompileCondition(condition *expression.Expression, successLab
 		}
 
 		switch value := value.(type) {
-		case eval.Number:
+		case *eval.Number:
 			if value.Number == 0 {
 				f.Jump(asm.JUMP, failLabel)
 			}
-		case eval.Register:
+		case *eval.Register:
 			f.RegisterNumber(asm.COMPARE, value.Register, 0)
 			f.Jump(asm.JE, failLabel)
 		default:

src/core/CompileFor.go

@@ -75,10 +75,10 @@ func (f *Function) CompileFor(loop *ast.For) error {
 	}
 
 	switch value := value.(type) {
-	case eval.Number:
+	case *eval.Number:
 		f.AddLabel(label)
 		f.RegisterNumber(asm.COMPARE, counter, value.Number)
-	case eval.Register:
+	case *eval.Register:
 		if value.IsAlive() {
 			tmp := f.NewRegister()
 			f.RegisterRegister(asm.MOVE, tmp, value.Register)

src/core/CompileLen.go

@@ -35,9 +35,9 @@ func (f *Function) CompileLen(root *expression.Expression) error {
 	f.SaveRegister(output)
 
 	switch value := value.(type) {
-	case eval.Register:
+	case *eval.Register:
 		memory.Base = value.Register
-	case eval.Label:
+	case *eval.Label:
 		f.RegisterLabel(asm.MOVE, output, value.Label)
 		memory.Base = output
 	default:

src/core/Evaluate.go

@@ -10,7 +10,7 @@ import (
 // Evaluate evaluates an expression and returns a value.
 func (f *Function) Evaluate(expr *expression.Expression) (eval.Value, error) {
 	if expr.IsFolded {
-		value := eval.Number{
+		value := &eval.Number{
 			Typ:    types.AnyInt,
 			Number: expr.Value,
 		}
@@ -36,7 +36,7 @@ func (f *Function) Evaluate(expr *expression.Expression) (eval.Value, error) {
 	tmp := f.NewRegister()
 	typ, err := f.ExpressionToRegister(expr, tmp)
 
-	value := eval.Register{
+	value := &eval.Register{
 		Typ:      typ,
 		Register: tmp,
 	}

src/core/EvaluateArray.go

@@ -12,12 +12,12 @@ import (
 )
 
 // EvaluateArray evaluates an array access.
-func (f *Function) EvaluateArray(expr *expression.Expression) (eval.Memory, error) {
+func (f *Function) EvaluateArray(expr *expression.Expression) (*eval.Memory, error) {
 	name := expr.Children[0].Token.Text(f.File.Bytes)
 	base := f.VariableByName(name)
 
 	if base == nil {
-		return eval.Memory{}, errors.New(&errors.UnknownIdentifier{Name: name}, f.File, expr.Children[0].Token.Position)
+		return nil, errors.New(&errors.UnknownIdentifier{Name: name}, f.File, expr.Children[0].Token.Position)
 	}
 
 	defer f.UseVariable(base)
@@ -33,17 +33,17 @@ func (f *Function) EvaluateArray(expr *expression.Expression) (eval.Memory, erro
 	index, err := f.Evaluate(indexExpr)
 
 	if err != nil {
-		return eval.Memory{}, err
+		return nil, err
 	}
 
 	if !types.Is(index.Type(), types.AnyInt) {
-		return eval.Memory{}, errors.New(&errors.TypeMismatch{Encountered: index.Type().Name(), Expected: types.AnyInt.Name()}, f.File, indexExpr.Token.Position)
+		return nil, errors.New(&errors.TypeMismatch{Encountered: index.Type().Name(), Expected: types.AnyInt.Name()}, f.File, indexExpr.Token.Position)
 	}
 
 	switch index := index.(type) {
-	case eval.Number:
+	case *eval.Number:
 		memory.Offset = int8(index.Number)
-	case eval.Register:
+	case *eval.Register:
 		memory.OffsetRegister = index.Register
 	default:
 		panic(fmt.Errorf("%s: not implemented: %v", f.UniqueName, index))
@@ -52,7 +52,7 @@ func (f *Function) EvaluateArray(expr *expression.Expression) (eval.Memory, erro
 	array, isArray := base.Value.Typ.(*types.Array)
 
 	if isArray {
-		value := eval.Memory{
+		value := &eval.Memory{
 			Typ:    array.Of,
 			Memory: memory,
 		}
@@ -63,7 +63,7 @@ func (f *Function) EvaluateArray(expr *expression.Expression) (eval.Memory, erro
 	pointer, isPointer := base.Value.Typ.(*types.Pointer)
 
 	if isPointer {
-		value := eval.Memory{
+		value := &eval.Memory{
 			Typ:    pointer.To,
 			Memory: memory,
 		}

src/core/EvaluateCall.go

@@ -6,14 +6,14 @@ import (
 )
 
 // EvaluateCall evaluates a function call.
-func (f *Function) EvaluateCall(expr *expression.Expression) (eval.Register, error) {
+func (f *Function) EvaluateCall(expr *expression.Expression) (*eval.Register, error) {
 	typ, err := f.CompileCall(expr)
 
 	if err != nil {
-		return eval.Register{}, err
+		return nil, err
 	}
 
-	value := eval.Register{Register: f.CPU.Output[0]}
+	value := &eval.Register{Register: f.CPU.Output[0]}
 
 	if len(typ) > 0 {
 		value.Typ = typ[0]

src/core/EvaluateDot.go

@@ -29,7 +29,7 @@ func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error)
 			return nil, errors.New(&errors.UnknownStructField{StructName: structure.Name(), FieldName: rightText}, f.File, right.Token.Position)
 		}
 
-		value := eval.Memory{
+		value := &eval.Memory{
 			Typ: field.Type,
 			Memory: asm.Memory{
 				Base:           variable.Value.Register,
@@ -51,7 +51,7 @@ func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error)
 			return nil, err
 		}
 
-		value := eval.Number{
+		value := &eval.Number{
 			Typ:    types.AnyInt,
 			Number: number,
 		}
@@ -65,7 +65,7 @@ func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error)
 	if exists {
 		f.File.Imports[leftText].Used = true
 
-		value := eval.Label{
+		value := &eval.Label{
 			Typ:   types.AnyPointer,
 			Label: function.UniqueName,
 		}

src/core/EvaluateToken.go

@@ -16,7 +16,7 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 		name := t.Text(f.File.Bytes)
 
 		if name == "true" {
-			value := eval.Number{
+			value := &eval.Number{
 				Typ:    types.Bool,
 				Number: 1,
 			}
@@ -25,7 +25,7 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 		}
 
 		if name == "false" {
-			value := eval.Number{
+			value := &eval.Number{
 				Typ:    types.Bool,
 				Number: 0,
 			}
@@ -37,11 +37,11 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 
 		if variable != nil {
 			f.UseVariable(variable)
-			return variable.Value, nil
+			return &variable.Value, nil
 		}
 
 		if function != nil {
-			value := eval.Label{
+			value := &eval.Label{
 				Typ:   types.AnyPointer,
 				Label: function.UniqueName,
 			}
@@ -58,7 +58,7 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 			return nil, err
 		}
 
-		value := eval.Number{
+		value := &eval.Number{
 			Typ:    types.AnyInt,
 			Number: number,
 		}
@@ -74,7 +74,7 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 		copy(slice[8:], data)
 		label := f.AddBytes(slice)
 
-		value := eval.Label{
+		value := &eval.Label{
 			Typ:   types.String,
 			Label: label,
 		}

src/core/ValueToMemory.go

@@ -8,16 +8,16 @@ import (
 // ValueToMemory moves a value into a memory region.
 func (f *Function) ValueToMemory(value eval.Value, memory asm.Memory) {
 	switch value := value.(type) {
-	case eval.Number:
+	case *eval.Number:
 		f.MemoryNumber(asm.STORE, memory, value.Number)
-	case eval.Register:
+	case *eval.Register:
 		f.MemoryRegister(asm.STORE, memory, value.Register)
-	case eval.Memory:
+	case *eval.Memory:
 		tmp := f.NewRegister()
 		f.MemoryRegister(asm.LOAD, value.Memory, tmp)
 		f.MemoryRegister(asm.STORE, memory, tmp)
 		f.FreeRegister(tmp)
-	case eval.Label:
+	case *eval.Label:
 		f.MemoryLabel(asm.STORE, memory, value.Label)
 	}
 }

src/core/ValueToRegister.go

@@ -9,13 +9,13 @@ import (
 // ValueToRegister moves a value into a register.
 func (f *Function) ValueToRegister(value eval.Value, register cpu.Register) {
 	switch value := value.(type) {
-	case eval.Number:
+	case *eval.Number:
 		f.RegisterNumber(asm.MOVE, register, value.Number)
-	case eval.Register:
+	case *eval.Register:
 		f.RegisterRegister(asm.MOVE, register, value.Register)
-	case eval.Memory:
+	case *eval.Memory:
 		f.MemoryRegister(asm.LOAD, value.Memory, register)
-	case eval.Label:
+	case *eval.Label:
 		f.RegisterLabel(asm.MOVE, register, value.Label)
 	}
 }

src/eval/Label.go

@@ -8,10 +8,10 @@ type Label struct {
 	Label string
 }
 
-func (v Label) String() string {
+func (v *Label) String() string {
 	return "Label"
 }
 
-func (v Label) Type() types.Type {
+func (v *Label) Type() types.Type {
 	return v.Typ
 }

src/eval/Memory.go

@@ -11,10 +11,10 @@ type Memory struct {
 	Memory asm.Memory
 }
 
-func (v Memory) String() string {
+func (v *Memory) String() string {
 	return "Memory"
 }
 
-func (v Memory) Type() types.Type {
+func (v *Memory) Type() types.Type {
 	return v.Typ
 }

src/eval/Number.go

@@ -8,10 +8,10 @@ type Number struct {
 	Number int
 }
 
-func (v Number) String() string {
+func (v *Number) String() string {
 	return "Number"
 }
 
-func (v Number) Type() types.Type {
+func (v *Number) Type() types.Type {
 	return v.Typ
 }

src/eval/Register.go

@@ -12,10 +12,24 @@ type Register struct {
 	Register cpu.Register
 }
 
-func (v Register) String() string {
+func (v *Register) String() string {
 	return "Register"
 }
 
-func (v Register) Type() types.Type {
+func (v *Register) Type() types.Type {
 	return v.Typ
 }
+
+// IsAlive returns true if the register value is still alive.
+func (v *Register) IsAlive() bool {
+	return v.Alive > 0
+}
+
+// Use reduces the lifetime counter by one.
+func (v *Register) Use() {
+	if v.Alive == 0 {
+		panic("incorrect number of value use calls")
+	}
+
+	v.Alive--
+}

src/eval/Value.go

@@ -9,17 +9,3 @@ type Value interface {
 	String() string
 	Type() types.Type
 }
-
-// IsAlive returns true if the register value is still alive.
-func (v *Register) IsAlive() bool {
-	return v.Alive > 0
-}
-
-// Use reduces the lifetime counter by one.
-func (v *Register) Use() {
-	if v.Alive == 0 {
-		panic("incorrect number of value use calls")
-	}
-
-	v.Alive--
-}