How to override an unpluggable parent theme function?

I have a PHP template in my child theme that calls a function ale_filter(), via

        <div class="articles">
            <?php ale_filter($_POST);?>
        </div>

The function is defined in a parent theme file: /aletheme/functions.filter.php. I would like to copy this file to my child theme, make edits to the function, and ensure the PHP template in-question calls this function, and not the parent theme function. How do I do so?

I have already copied the parent theme file to my child theme, using the same file name and relative path (/aletheme/functions/filter.php).

A previous Stack Exchange question linked to a page with three methods. Those three methods were:

• Taking advantage of pluggable functions – This method applies only if the parent theme function is pluggable. Mine is not.
• Increase priority for child theme function – I’m not entirely sure how to do so in my case. The example given was for a parent theme function attached to a WordPress hook, and mine is not. The PHP man page on proc_nice wasn’t that clear either. I guess I could follow-up on that a bit though. Maybe someone here has ideas.
• Making use of hooks, actions and filters – This method applies only if the parent theme function is attached to a WordPress hook. I don’t believe that applies in my case.
  

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I found several other Stack Exchange questions, but the answers in all described methods that I do not think apply in my case:

• How to override parent theme function through the child theme
• Function in Child Theme not overriding Parent Theme function
• How to override function in child theme
• How to override the Parent theme Function into child themes functions.php
• How to override parent functions in child themes?

Thanks.

Since the function is used in your child theme’s template there’s nothing stopping you from using a function with a different name. So you don’t actually need to plug the function, you just need to create a function that does what you want and use that instead.

So copy ale_filter() to your child theme, rename it something like ale_child_filter(), change it however you like, and then just change your template to use that function.

You only need to plug a function if the function is used somewhere that you can’t overwrite with your child theme. Plugging it would allow you redefine a function when you don’t have access to change where the function is used. Since you do have the ability to change which function is used, plugging the function is unnecessary.