Function array_prepend 

fn array_prepend(
    left: Option<ScalarRefImpl<'_>>,
    right: Option<ListRef<'_>>,
    writer: &mut impl ListWrite,
)

Prepends a value as the front element of an array. The behavior is the same as PG.

Examples:

query T
select array_prepend(123, array[66]);
----
{123,66}

query T
select array_prepend(null::int, array[66]);
----
{NULL,66}

query T
select array_prepend(233, null::int[]);
----
{233}

query T
select array_prepend(null::int, null::int[]);
----
{NULL}