/**
* Takes an array of integers representing the Unicode characters and returns
* a UTF-8 string.
*
* @param array $unicode The array of Unicode code points
* @param bool $strict Should the function throw an error if something goes wrong
* @return string The UTF-8 encoded string or false on failure
*/
function utf8_from_unicode($unicode, $strict = false)
{
$rv = '';
$count = count($unicode);
for ($i = 0; $i < $count; $i++) {
$cp = $unicode[$i];
if (utf8_is_ascii($cp)) {
$rv .= chr($cp);
continue;
}
if (!unicode_is_valid($cp)) {
if ($strict) {
$msg = unicode_is_surrogate($cp) ? 'Illegal surrogate in UTF-8' : 'Codepoint out of Unicode range';
trigger_error(sprintf('utf8_from_unicode: %s at index: %d, value: 0x%X', $msg, $i, $cp));
return false;
}
continue;
}
$seqlen = utf8_sequence_length($cp);
$rv .= chr(utf8_encode_identifier($cp, $seqlen));
$offset = $seqlen - 2;
do {
$rv .= chr(utf8_encode_trail($cp, $offset));
} while ($offset--);
}
return $rv;
}
/**
* @dataProvider providerUnicodeIsValid
*/
public function testUnicodeIsValid($cp, $rv)
{
$this->assertEquals(unicode_is_valid($cp), $rv);
}
/**
* This function may return boolean false, but may also return a non-boolean 0
* which evaluates to false. Use the === operator for testing the return value
* of this function.
*
* @param string $str The UTF-8 encoded string
* @param int $i The current position of the string
* @param int $rcp If passed, this will be set to the Unicode code point
* for the character
* @return string The character or false on the start of the string
*/
function utf8_get_last_char($str, &$i = null, &$rcp = null)
{
if ($i === null) {
$i = strlen($str) - 1;
}
while (isset($str[$i])) {
$n = $i--;
// Save current position and move to the previous octet
$char = $str[$n++];
// Move to the next octet at once
$ord = ord($char);
if (utf8_is_ascii($ord)) {
$rcp = $ord;
return $char;
}
if (utf8_is_identifier($ord, $seqlen)) {
$cp = utf8_decode_identifier($ord, $seqlen);
$offset = $seqlen - 2;
// Check for exists the last octet of the sequence at once
if (!isset($str[$n + $offset])) {
continue;
}
do {
$ord = ord($str[$n]);
if (!utf8_is_trail($ord)) {
continue 2;
// Skip this sequence
}
$cp |= utf8_decode_trail($ord, $offset);
$char .= $str[$n++];
} while ($offset--);
if (unicode_is_valid($cp) && utf8_sequence_length($cp) == $seqlen) {
$rcp = $cp;
return $char;
}
}
}
return false;
}
