56 throw new UnexpectedValueException(
"Alphabet must be < 4096 items" );
62 $this->puaSubset = [];
64 for ( $i = 0; $i < $len; $i++ ) {
65 $this->puaSubset[] =
"\xF3\xB3" . chr( floor( $i / 64 ) + 128 ) . chr( ( $i % 64 ) + 128 );
70 $lengths = array_map(
'mb_strlen', $this->alphabet );
71 array_multisort( $lengths, SORT_DESC, $this->firstLetters, $this->alphabet, $this->puaSubset );
73 parent::__construct(
$lang );
77 return str_replace( $this->alphabet, $this->puaSubset, $string );
81 return $this->
convertToPua( parent::getSortKey( $string ) );
90 $index = array_search( substr( $sortkey, 0, 4 ), $this->puaSubset );
91 if ( $index !==
false ) {
92 return $this->firstLetters[ $index ];
96 return parent::getFirstLetter( $string );