HH\Lib\Vec\diff

Returns a new vec containing only the elements of the first Traversable that do not appear in any of the other ones

namespace HH\Lib\Vec;

function diff<Tv1 as arraykey, Tv2 as arraykey>(
  Traversable<Tv1> $first,
  Traversable<Tv2> $second,
  Container<Tv2> ...$rest,
): vec<Tv1>;

For vecs that contain non-arraykey elements, see Vec\diff_by().

Time complexity: O(n + m), where n is size of $first and m is the combined size of $second plus all the ...$rest Space complexity: O(n + m), where n is size of $first and m is the combined size of $second plus all the ...$rest -- note that this is bigger than O(n)

Parameters

• Traversable<Tv1>$first
• Traversable<Tv2>$second
• Container<Tv2>...$rest

Returns

• vec<Tv1>

Examples

$example_vec1 = vec[1,2,3,4,5];
$example_vec2 = vec[1,3];

$diffed_vec = Vec\diff($example_vec1, $example_vec2);
print_r($diffed_vec);
// result: [2,4,5]

$example_vec3 = vec[6,7];

$diffed_vec = Vec\diff($example_vec1, $example_vec3);
print_r($diffed_vec);
// result: [1,2,3,4,5]