php function for unpack arrays

index.php

<?php

$array = [
	"Complimenti",
	"ora",
	"puoi",
	[
		"inviare",
		[
			"la tua",
			"candidatura!"
		]
	]
];

function compute($curr, ...$arr){
	$result = "";
	switch(gettype($curr)){
		case "string":
			$result .= $curr;
			break;
		case "array":
			$result .= compute(...$curr);
			break;
		default:
	}
	if(count($arr) == 0){
		return $result;
	}
	return $result . " " . compute(...$arr);
}

echo compute(...$array);