Function array_replace

fn array_replace(
    array: ListRef<'_>,
    elem_from: Option<ScalarRefImpl<'_>>,
    elem_to: Option<ScalarRefImpl<'_>>,
) -> ListValue

Replaces each array element equal to the second argument with the third argument.

Examples:

query T
select array_replace(array[7, null, 8, null], null, 0.5);
----
{7,0.5,8,0.5}

query T
select array_replace(null, 1, 5);
----
NULL

query T
select array_replace(null, null, null);
----
NULL

statement error
select array_replace(array[3, null, 4], true, false);

# Replacing `int` in multidimensional array is not supported yet. (OK in PostgreSQL)
statement error
select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], 3, 9);

# Unlike PostgreSQL, it is okay to replace `int[][]` inside `int[][][]`.
query T
select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], array[array[4, 5], array[6, 7]], array[array[2, 3], array[4, 5]]);
----
{{{0,1},{2,3}},{{2,3},{4,5}}}

# Replacing `int[]` inside `int[][][]` is not supported by either PostgreSQL or RisingWave.
# This may or may not be supported later, whichever makes the `int` support above simpler.
statement error
select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], array[4, 5], array[8, 9]);