How to namespace global function overrides?

One may question the utility of such function in the first place, with several aspects to take into account:

• Discoverability. That is, how I, working on your project, am expected to know that trim_also (or the modified trim) exists in the first place? How would I find it? Would my IDE, at some point, show it to me during autocompletion?

  Note that the answer to this question would guide you through the proper choice of the namespace.

• Scope. Is this something very local, with a narrow scope, or the opposite, something shared between many different projects or transcending one huge project?

  Here too, the choice of the namespace would strongly depend on the answer.

• Pertinence. Why would I need to use such function, as opposed to just having a string " \n\r\t\v\x00" stored somewhere in the code, that I can combine with my own set of characters to trim?

• Use cases. How many times do I need to extend the base set of characters? How often those base set of characters actually matter? Don't know the specifics of your project, but virtually every time I had to use trim in any language, I was rather trimming something very specific—either some very domain-specific characters (say square brackets, for instance) or a series of carefully crafted characters, such as everything that is a whitespace. It was never the list you quoted—the zero byte at the end of especially... curious.

The premise of the question seems to be that trim() is the right name, now we just need to find a good class name because Composer wants a class when autoloading files. Instead, I would like to consider the semantics behind the additional characters (or why '' is a better default). What do these default characters mean from your application's perspective? Why isn't plain old trim() good enough?

Find that reason why, and use that to give your trim a better name. Once you have a better name for your "trim override", then let that guide your choice of name for the class that contains it.

Some other design and naming considerations:

• If these functions are local utilities for a single application, consider omitting the namespace and just specify a class name or use some generic utils\ namespace.
• If this is a general purpose utility which you alone are writing, and the potential audience is the general public (i.e., you are working on open-source), then use your own specific username as the root namespace. The goal here is to be unique within some package repository like Composer.
• If this is a general purpose utility reusable by anyone at your organization, consider a namespace like myCompany\utils\. It should still be unique within your organization, even if you are using an internal package repository for Composer.