Marc Morera has a new post to his site wanting to help you defeat Symfony's expression language and perform the same functionality, just more on the code side (another option).

How beautiful Expression Language definitions are, right? I mean, inserting that complex expressions in a Dependency Injection configuration file is so nice and fast if you need to inject the result of a method in a service (one of the multiple examples we can see). [...] This is not a bad idea, really, but because we are engineers and we should have as much information as possible in order to be able to choose between the best option, always, I will show you another way of defining this piece of code.

He shows how to write some code using the Factory design pattern structure to reproduce a bit more complex piece of expression language. He shows the setup of the services.yml file to define the "managers" and classes/services to be injected. He also notes that this removes the need for the "symfony/expression-language" dependency and makes things more portable in the future.