Implemented complex expressions

examples/hello/hello.q

@@ -11,7 +11,10 @@ hello() {
 	address += 4194304
 	address += 1
 
-	length = 0
+	length = 0 + 1
+	length -= length
+	length += write + stdout
+	length -= length
 	length += 50
 	length -= 20
 	length *= 10

src/build/Assignment.go

@@ -1,9 +1,6 @@
 package build
 
 import (
-	"strconv"
-
-	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/expression"
 	"git.akyoto.dev/cli/q/src/errors"
 )
@@ -11,31 +8,21 @@ import (
 // CompileAssignment compiles an assignment.
 func (f *Function) CompileAssignment(expr *expression.Expression) error {
 	name := expr.Children[0].Token.Text()
-	register := f.Variables[name].Register
+	variable, exists := f.Variables[name]
 
-	switch expr.Token.Text() {
+	if !exists {
-	case "=":
+		return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, expr.Children[0].Token.Position)
-		f.ExpressionToRegister(expr.Children[1], register)
-
-	case "+=":
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		f.Assembler.RegisterNumber(asm.ADD, register, number)
-
-	case "-=":
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		f.Assembler.RegisterNumber(asm.SUB, register, number)
-
-	case "*=":
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		f.Assembler.RegisterNumber(asm.MUL, register, number)
-
-	case "/=":
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		f.Assembler.RegisterNumber(asm.DIV, register, number)
-
-	default:
-		return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
 	}
 
-	return nil
+	if expr.Token.Text() == "=" {
+		return f.ExpressionToRegister(expr.Children[1], variable.Register)
+	}
+
+	right := expr.Children[1]
+
+	if right.IsLeaf() {
+		return f.Calculate(variable.Register, expr.Token, right.Token)
+	}
+
+	return f.Execute(expr.Token, variable.Register, expr.Children[1])
 }

src/build/Calculate.go

@@ -0,0 +1,81 @@
+package build
+
+import (
+	"strconv"
+
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/token"
+	"git.akyoto.dev/cli/q/src/errors"
+)
+
+// Calculate performs an operation on a register with the given operand.
+func (f *Function) Calculate(register cpu.Register, operation token.Token, operand token.Token) error {
+	switch operand.Kind {
+	case token.Number:
+		value := operand.Text()
+		number, err := strconv.Atoi(value)
+
+		if err != nil {
+			return err
+		}
+
+		return f.CalculateRegisterNumber(operation, register, number)
+
+	case token.Identifier:
+		name := operand.Text()
+		variable, exists := f.Variables[name]
+
+		if !exists {
+			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, operand.Position)
+		}
+
+		return f.CalculateRegisterRegister(operation, register, variable.Register)
+	}
+
+	return errors.New(errors.NotImplemented, f.File, operation.Position)
+}
+
+// CalculateRegisterNumber performs an operation on a register and a number.
+func (f *Function) CalculateRegisterNumber(operation token.Token, register cpu.Register, number int) error {
+	switch operation.Text() {
+	case "+", "+=":
+		f.Assembler.RegisterNumber(asm.ADD, register, number)
+
+	case "-", "-=":
+		f.Assembler.RegisterNumber(asm.SUB, register, number)
+
+	case "*", "*=":
+		f.Assembler.RegisterNumber(asm.MUL, register, number)
+
+	case "/", "/=":
+		f.Assembler.RegisterNumber(asm.DIV, register, number)
+
+	default:
+		return errors.New(errors.NotImplemented, f.File, operation.Position)
+	}
+
+	return nil
+}
+
+// CalculateRegisterRegister performs an operation on two registers.
+func (f *Function) CalculateRegisterRegister(operation token.Token, destination cpu.Register, source cpu.Register) error {
+	switch operation.Text() {
+	case "+", "+=":
+		f.Assembler.RegisterRegister(asm.ADD, destination, source)
+
+	case "-", "-=":
+		f.Assembler.RegisterRegister(asm.SUB, destination, source)
+
+	case "*", "*=":
+		f.Assembler.RegisterRegister(asm.MUL, destination, source)
+
+	case "/", "/=":
+		f.Assembler.RegisterRegister(asm.DIV, destination, source)
+
+	default:
+		return errors.New(errors.NotImplemented, f.File, operation.Position)
+	}
+
+	return nil
+}

src/build/Function.go

@@ -122,60 +122,45 @@ func (f *Function) CompileInstruction(line token.List) error {
 
 // ExpressionToRegister moves the result of an expression into the given register.
 func (f *Function) ExpressionToRegister(root *expression.Expression, register cpu.Register) error {
+	operation := root.Token
+
 	if root.IsLeaf() {
-		return f.TokenToRegister(root.Token, register)
+		return f.TokenToRegister(operation, register)
 	}
 
 	left := root.Children[0]
 	right := root.Children[1]
 
-	f.ExpressionToRegister(left, register)
+	err := f.ExpressionToRegister(left, register)
 
-	if right.IsLeaf() {
+	if err != nil {
-		value := right.Token.Text()
+		return err
-		n, err := strconv.Atoi(value)
-
-		if err != nil {
-			return err
-		}
-
-		switch root.Token.Text() {
-		case "+":
-			f.Assembler.RegisterNumber(asm.ADD, register, n)
-
-		case "-":
-			f.Assembler.RegisterNumber(asm.SUB, register, n)
-
-		case "*":
-			f.Assembler.RegisterNumber(asm.MUL, register, n)
-
-		case "/":
-			f.Assembler.RegisterNumber(asm.DIV, register, n)
-		}
-
-		return nil
-	} else {
-		temporary, _ := f.CPU.FindFree(f.CPU.General)
-		f.CPU.Use(temporary)
-		f.ExpressionToRegister(right, temporary)
-		f.CPU.Free(temporary)
-
-		switch root.Token.Text() {
-		case "+":
-			f.Assembler.RegisterRegister(asm.ADD, register, temporary)
-
-		case "-":
-			f.Assembler.RegisterRegister(asm.SUB, register, temporary)
-
-		case "*":
-			f.Assembler.RegisterRegister(asm.MUL, register, temporary)
-
-		case "/":
-			f.Assembler.RegisterRegister(asm.DIV, register, temporary)
-		}
 	}
 
-	return errors.New(errors.NotImplemented, f.File, root.Token.Position)
+	return f.Execute(operation, register, right)
+}
+
+// Execute executes an operation on a register with a value operand.
+func (f *Function) Execute(operation token.Token, register cpu.Register, value *expression.Expression) error {
+	if value.IsLeaf() {
+		return f.Calculate(register, operation, value.Token)
+	}
+
+	temporary, found := f.CPU.FindFree(f.CPU.General)
+
+	if !found {
+		panic("no free registers")
+	}
+
+	f.CPU.Use(temporary)
+	defer f.CPU.Free(temporary)
+	err := f.ExpressionToRegister(value, temporary)
+
+	if err != nil {
+		return err
+	}
+
+	return f.CalculateRegisterRegister(operation, register, temporary)
 }
 
 // TokenToRegister moves a token into a register.
@@ -190,7 +175,7 @@ func (f *Function) TokenToRegister(t token.Token, register cpu.Register) error {
 			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, t.Position)
 		}
 
-		f.Assembler.MoveRegisterRegister(register, variable.Register)
+		f.Assembler.RegisterRegister(asm.MOVE, register, variable.Register)
 		return nil
 
 	case token.Number:

src/build/VariableDefinition.go

@@ -2,7 +2,6 @@ package build
 
 import (
 	"git.akyoto.dev/cli/q/src/build/expression"
-	"git.akyoto.dev/cli/q/src/build/token"
 	"git.akyoto.dev/cli/q/src/errors"
 )
 
@@ -18,27 +17,18 @@ func (f *Function) CompileVariableDefinition(expr *expression.Expression) error
 		return errors.New(&errors.VariableAlreadyExists{Name: name}, f.File, expr.Children[0].Token.Position)
 	}
 
-	value := expr.Children[1]
-
-	err := value.EachLeaf(func(leaf *expression.Expression) error {
-		if leaf.Token.Kind == token.Identifier && !f.identifierExists(leaf.Token.Text()) {
-			return errors.New(&errors.UnknownIdentifier{Name: leaf.Token.Text()}, f.File, leaf.Token.Position)
-		}
-
-		return nil
-	})
-
-	if err != nil {
-		return err
-	}
-
 	reg, exists := f.CPU.FindFree(f.CPU.General)
 
 	if !exists {
 		panic("no free registers")
 	}
 
-	f.ExpressionToRegister(value, reg)
+	err := f.ExpressionToRegister(expr.Children[1], reg)
+
+	if err != nil {
+		return err
+	}
+
 	f.CPU.Use(reg)
 
 	f.Variables[name] = &Variable{

src/build/asm/Instructions.go

@@ -24,17 +24,6 @@ func (a *Assembler) RegisterRegister(mnemonic Mnemonic, left cpu.Register, right
 	})
 }
 
-// MoveRegisterRegister moves a register value into another register.
-func (a *Assembler) MoveRegisterRegister(destination cpu.Register, source cpu.Register) {
-	a.Instructions = append(a.Instructions, Instruction{
-		Mnemonic: MOVE,
-		Data: &RegisterRegister{
-			Destination: destination,
-			Source:      source,
-		},
-	})
-}
-
 // Label adds a label at the current position.
 func (a *Assembler) Label(name string) {
 	a.Instructions = append(a.Instructions, Instruction{

src/build/asm/RegisterNumber.go

@@ -14,5 +14,5 @@ type RegisterNumber struct {
 
 // String returns a human readable version.
 func (data *RegisterNumber) String() string {
-	return fmt.Sprintf("%s, %Xₕ", data.Register, data.Number)
+	return fmt.Sprintf("%s, %d", data.Register, data.Number)
 }