Added more tests

src/build/Function.go

@@ -156,29 +156,10 @@ func (f *Function) CompileFunctionCall(expr *expression.Expression) error {
 	parameters := expr.Children[1:]
 
 	for i, parameter := range parameters {
-		switch parameter.Token.Kind {
-		case token.Identifier:
-			name := parameter.Token.Text()
-			variable, exists := f.Variables[name]
+		err := f.ExpressionToRegister(parameter, f.CPU.Syscall[i])
 
-			if !exists {
-				panic("Unknown identifier " + name)
-			}
-
-			if !variable.IsConst {
-				panic("Not implemented yet")
-			}
-
-			n, _ := strconv.Atoi(variable.Value.Token.Text())
-			f.Assembler.MoveRegisterNumber(f.CPU.Syscall[i], uint64(n))
-
-		case token.Number:
-			value := parameter.Token.Text()
-			n, _ := strconv.Atoi(value)
-			f.Assembler.MoveRegisterNumber(f.CPU.Syscall[i], uint64(n))
-
-		default:
-			panic("Unknown expression")
+		if err != nil {
+			return err
 		}
 	}
 
@@ -191,6 +172,59 @@ func (f *Function) CompileFunctionCall(expr *expression.Expression) error {
 	return nil
 }
 
+// ExpressionToRegister moves the result of an expression into the given register.
+func (f *Function) ExpressionToRegister(root *expression.Expression, register cpu.Register) error {
+	if root.IsLeaf() {
+		return f.TokenToRegister(root.Token, register)
+	}
+
+	return errors.New(errors.NotImplemented, f.File, root.Token.Position)
+}
+
+// TokenToRegister moves a token into a register.
+// It only works with identifiers, numbers and strings.
+func (f *Function) TokenToRegister(t token.Token, register cpu.Register) error {
+	switch t.Kind {
+	case token.Identifier:
+		name := t.Text()
+		variable, exists := f.Variables[name]
+
+		if !exists {
+			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, t.Position)
+		}
+
+		if !variable.IsConst {
+			return errors.New(errors.NotImplemented, f.File, t.Position)
+		}
+
+		n, err := strconv.Atoi(variable.Value.Token.Text())
+
+		if err != nil {
+			return err
+		}
+
+		f.Assembler.MoveRegisterNumber(register, uint64(n))
+		return nil
+
+	case token.Number:
+		value := t.Text()
+		n, err := strconv.Atoi(value)
+
+		if err != nil {
+			return err
+		}
+
+		f.Assembler.MoveRegisterNumber(register, uint64(n))
+		return nil
+
+	case token.String:
+		return errors.New(errors.NotImplemented, f.File, t.Position)
+
+	default:
+		return errors.New(errors.InvalidExpression, f.File, t.Position)
+	}
+}
+
 // PrintAsm shows the assembly instructions.
 func (f *Function) PrintAsm() {
 	ansi.Bold.Println(f.Name)