/**
* This method returns a string representing a sequence of substring delimited by the
* specified string.
*
* @access public
* @static
* @param IString\Type $xs the delimiter
* @param ISeq\Type $ys a sequence of substrings
* @return IString\Type the string
*/
public static function join(IString\Type $xs, ISeq\Type $ys)
{
$zs = array_map(function (IString\Type $y) : bool {
return $y->unbox();
}, $ys->unbox());
return IString\Type::box(implode($xs->unbox(), $zs));
}
/**
* This method returns a formatted string using the specified sequence of objects.
*
* @access public
* @static
* @param IString\Type $xs the string to be formatted
* @param ISeq\Type $ys the objects to be incorporated
* @return IString\Type the newly formatted string
*/
public static function format(IString\Type $xs, ISeq\Type $ys) : IString\Type
{
$buffer = $xs->unbox();
$length = $ys->length();
for ($i = IInt32\Type::zero(); IInt32\Module::lt($i, $length)->unbox(); $i = IInt32\Module::increment($i)) {
$search = '{' . $i->__toString() . '}';
$buffer = str_replace($search, $ys->item($i)->__toString(), $buffer);
}
return IString\Type::box($buffer);
}
/**
* This method returns the sum of all items in the list.
*
* @access public
* @static
* @param ISeq\Type $xs the sequence to be processed
* @return IDouble\Type the result
*/
public static function sum(ISeq\Type $xs) : IDouble\Type
{
return $xs->foldLeft(function (IDouble\Type $c, INumber\Type $x) {
return IDouble\Module::add($c, $x->toDouble());
}, IDouble\Type::zero());
}
