Proposal for functions that handle prefixes and suffixes

I don't recall ever needing to ensure prefixes or suffixes, but I have
wanted to prepend or append a string to an array of strings. Maybe there is
some demand for "ensuring" when working with phone numbers or product SKUs.
I don't know.

Whatever logic is required for a given scenario, does this need to be built
into the core? I once asked about adding array_transpose() to the core, and
the response boiled down to: PHP doesn't need a core function for every
possible data manipulation.

Topically, circa 2024-03-24, I proposed to modify substr_replace() which is
a solid go-to for prepending, but not appending. (Subject: "Proposal: Make
$offset of substr_replace null by default") This is because the offset
parameter does not accept null. Food for thought.

substr_replace(
array|string $string,
array|string $replace,
array|int $offset,
array|int|null $length = null
): string|array

Contextual usages:

• [Add prefix string to each value of a flat array][
  https://stackoverflow.com/a/78210830/2943403]

-[Fastest way to add a prefix to all array keys?][
https://stackoverflow.com/a/76196482/2943403]

• [Regex to Add a postfix to each item of a PHP array][
  https://stackoverflow.com/a/79083258/2943403]

Mick

Hi

Nevertheless, the idea is that in php code many times we have to deal
with
prefixes or suffixes of strings, this comes up a lot when you are dealing
with file names or urls. Some examples

From the back of my mind I seem to remember that this was previously
proposed with similar use cases, since I can remember saying the same
I'm saying here before:

Filenames and URLs are probably the worst possible use case for this
feature, since they are “structured” strings where naively performing
string operations at best just results in garbage and at worst result in
security issues.

• If the domain includes a initial www part, remove it

This just seems unsafe, since you are likely making assumptions about
URLs you don't own.

• If the filename includes the .png extension, remove it

basename($filename, ".png");

• If the URL does not include the http:// schema, add it

Simply adding a prefix will break URLs that already have a scheme. Use
PHP 8.5's URI extension instead.

• If the URL is missing a trailing slash, add it
• If the URL starts with http://, change it to https://

URI extension.

• If the filename ends in .jpeg, change it to .jpg

Here you probably want to have more than one mapping (e.g. .htm to
.html), so you would probably use a combination of pathinfo() and a
lookup table.

function replace_prefix(string $source, string $prefix, string $replace):
string
function replace_suffix(string $source, string $suffix, string $replace):
string

Replace a prefix or suffix in a string it the string has it

This parameter order is inconsistent with both str_replace and
preg_replace, which are likely the two closest existing functions we have.

Naming-wise these functions should definitely start with a
str_(pre|suf)fix_ prefix for proper grouping and autocompletion. Thus:

• str_prefix_add()
• str_prefix_remove()
• str_prefix_replace()
• str_suffix_add()
• str_suffix_remove()
• str_suffix_replace()

See also the corresponding policy:

https://github.com/php/policies/blob/main/coding-standards-and-naming.rst#functions

And of course Juris correctly pointed out that 'add' is misleading,
because the behavior is conditional.

I would like to know if the internals people think that the addition of
these functions would be interesting. If there is some interest I will
prepare a full RFC

For the reasons mentioned above, I don't see much value in the proposal.
Personally I've rarely needed the functionality in the past and the
cases where I needed it, it was a common enough operation that I could
just place it in a function myself.

Best regards
Tim Düsterhus