Add functions that work with suffixes and prefixes

[carlos-granados]

Adds 6 new functions which can be used to work with string suffixes and prefixes:

function str_prefix_ensure(string $prefix, string $subject): string
function str_suffix_ensure(string $suffix, string $subject): string

Add a prefix or suffix to a string only if the string does not yet have it

function str_prefix_remove(string $prefix, string $subject): string
function str_suffix_remove(string $suffix, string $subject): string

Remove a prefix or suffix from a string if the string has it

function str_prefix_replace(string $prefix, string $replace, string $subject): string
function str_suffix_replace(string $suffix, string $replace, string $subject): string

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

[iluuu1994]

Hi @carlos-granados. Thanks for your proposal. I think the addition of new string functions is controversial enough to warrant an RFC. See https://wiki.php.net/rfc/howto. I'm foreseeing some disagreements on naming / namespacing, among other things. The add_{suffix,prefix} functions are also pretty much pointless, unless you're working with higher order functions I guess.

[carlos-granados]

Hi @carlos-granados. Thanks for your proposal. I think the addition of new string functions is controversial enough to warrant an RFC. See https://wiki.php.net/rfc/howto. I'm foreseeing some disagreements on naming / namespacing, among other things. The add_{suffix,prefix} functions are also pretty much pointless, unless you're working with higher order functions I guess.

Thank @iluuu1994 yes, I was planning to create an RFC and in fact I did not intend to create this PR. I wanted to first create it in my fork but it seems that somehow I made a mistake and created it here. Now that it is created I'll leave it here.