This is bugging me:
Why preg_match('/pattern/', $haystack)
instead of preg_match('pattern', $haystack)
? Everything I've seen just states as a fact that they're necessary, and mentions that you can use alternate delimiters.
But, it's a function that defines its own interface outside of the string. It has a flags argument. Adding intra-string syntax seems capricious.
Is it something inherited from pcre that the authors were just not interested in working around? Yet another perverse fact of PHP? Or is there a justification?