Implemented assignments

src/build/Function.go

@@ -109,37 +109,32 @@ func (f *Function) CompileInstruction(line token.List) error {
 		return f.CompileVariableDefinition(expr)
 	}
 
+	if isAssignment(expr) {
+		return f.CompileAssignment(expr)
+	}
+
 	if isFunctionCall(expr) {
 		return f.CompileFunctionCall(expr)
 	}
 
-	if expr.Token.Kind == token.Operator {
-		name := expr.Children[0].Token.Text()
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		register := f.Variables[name].Register
-
-		switch expr.Token.Text() {
-		case "+=":
-			f.Assembler.RegisterNumber(asm.ADD, register, number)
-			return nil
-
-		case "-=":
-			f.Assembler.RegisterNumber(asm.SUB, register, number)
-			return nil
-
-		case "*=":
-			f.Assembler.RegisterNumber(asm.MUL, register, number)
-			return nil
-
-		case "/=":
-			f.Assembler.RegisterNumber(asm.DIV, register, number)
-			return nil
-		}
-	}
-
 	return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
 }
 
+// isAssignment returns true if the expression is an assignment.
+func isAssignment(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Bytes[len(expr.Token.Bytes)-1] == '='
+}
+
+// isFunctionCall returns true if the expression is a function call.
+func isFunctionCall(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == "λ"
+}
+
+// isVariableDefinition returns true if the expression is a variable definition.
+func isVariableDefinition(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == ":="
+}
+
 // 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() {