On Fri, Oct 28, 2016 at 7:37 PM, German Geek <geek.de@xxxxxxxxx> wrote:
> String functions are very fast. Regexes have to be compiled under the hood
> to take advantage of their speed.
A lover of assembly language could hand-code a routine to "count leading
whitespace of all known types" that would blow any other solution away.*
But every developer who came across it over the next decade would have to
learn it.**
Or you can write a function with unit tests so nobody ever has to read the
gory details again.***
/**
* Returns the leading whitespace from the given string or an empty
string for all else.
*
* @param string $input converted to string if needed
* @return string the leading whitespace or empty string if none
*/
function lspace($input) { // psuedably-cryptic c-style function name?
check!
if ($input && ($input = (str) $input)) { // micro-optimization
alert! no idea if this helps; totally defensive. kill?
if (preg_match('/^\s*/', $input, $matches)) { // ignore errors
like a boss (actually, this is fine here)
return $matches[0];
}
}
return ''; // Ask me a dumb question, get a dumb answer.
}
[Awesome unit tests here] [1]
Cheers!
David
* This could be baked into the regex library too.
** You'd wrap it in a function where most readers would never see it.
*** Did Unicode++ just drop? No problem, the PHP devs will fix preg_match
and "\s" before you could ever notice. Stay on top of updates!
**** Asterisk in regex is greedy so there's no need to find the end of the
whitespace nor capture a portion of the match. Simplify!
[1] http://ideone.com/PO2Xoq
