The code originates from the eZUTF8Codec class available in lib/ezi18n/classes/ezutf8codec.php
/**
* Compile a single source character definition into a plain UTF-8 character
*
* Handles the two formats from the possible character definitions:
* - U+xxxx : Unicode value in hexadecimal
* - xx: Ascii value in hexadecimal
*
* @param string $char
*
* @return string
*/
protected function compileCharacter($char)
{
switch (true) {
case preg_match('(^U\\+[0-9a-fA-F]{4}$)', $char):
return $this->converter->toUTF8Character(hexdec(substr($char, 2)));
case preg_match('(^[0-9a-fA-F]{2}$)', $char):
return chr(hexdec($char));
default:
throw new RuntimeException("Invalid character definition: {$char}");
}
}
