[PG Dialect] `SELECT ARRAY(SELECT 1)` fails to parse

[e-dard]

Whilst working on a project that uses sqlparser to parse some real SQL queries from a common PG client (PGAdmin 6.1) I found that the following query emitted by PGAdmin at startup fails to parse correctly:

SELECT
    roles.oid as id, roles.rolname as name,
    roles.rolsuper as is_superuser,
    CASE WHEN roles.rolsuper THEN true ELSE roles.rolcreaterole END as
    can_create_role,
    CASE WHEN roles.rolsuper THEN true
    ELSE roles.rolcreatedb END as can_create_db,
    CASE WHEN 'pg_signal_backend'=ANY(ARRAY(WITH RECURSIVE cte AS (
    SELECT pg_roles.oid,pg_roles.rolname FROM pg_roles
        WHERE pg_roles.oid = roles.oid
    UNION ALL
    SELECT m.roleid,pgr.rolname FROM cte cte_1
        JOIN pg_auth_members m ON m.member = cte_1.oid
        JOIN pg_roles pgr ON pgr.oid = m.roleid)
    SELECT rolname  FROM cte)) THEN True
    ELSE False END as can_signal_backend
FROM
    pg_catalog.pg_roles as roles
WHERE
    rolname = current_user

I poked around a bit and managed to reduce the failing query to:

SELECT ARRAY(SELECT 1))

which against PG 13 produces the following results:

edd=# SELECT ARRAY(SELECT 1);
 array 
-------
 {1}
(1 row)

However, the following program panics:

use sqlparser;

let q = "SELECT ARRAY(SELECT 1)";
let dialect = sqlparser::dialect::PostgreSqlDialect {};
let ast = sqlparser::parser::Parser::parse_sql(&dialect, &q).unwrap();    

with the following panic (due to an error being returned)

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ParserError("Expected ), found: 1")

Finally, if I change the query to something that is invalid in PG:

SELECT ARRAY(1);

then whilst this query fails against PG 13 it actually gets parsed by sqlparser:

[2022-01-06T18:38:38Z DEBUG sqlparser::parser] Parsing sql 'SELECT ARRAY(1)'...
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] parsing expr
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] parsing expr
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] prefix: Value(Number("1", false))
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] get_next_precedence() RParen
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] next precedence: 0
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] prefix: Function(Function { name: ObjectName([Ident { value: "ARRAY", quote_style: None }]), args: [Unnamed(Value(Number("1", false)))], over: None, distinct: false })
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] get_next_precedence() EOF
[2022-01-06T18:38:38Z DEBUG sqlparser::parser] next precedence: 0