Oracle query parse error when using "WITH FUNCTION"

[graymcd]

sqlglot 30.8.0
Oracle dialect
"WITH FUNCTION" in a query causes parsing error Expecting (. Line 1, Col: 20.

Query:

WITH FUNCTION f_demo(v_in_ch IN CHAR) RETURN CHAR
IS
BEGIN
    RETURN v_in_ch;
END;

SELECT
    'C' || f_demo('d')
FROM dual;

Repo code:

import sqlglot

query = """WITH FUNCTION f_demo(v_in_ch IN CHAR) RETURN CHAR
IS
BEGIN
    RETURN v_in_ch;
END;

SELECT
    'C' || f_demo('d')
FROM dual;"""

try:
    ast = sqlglot.parse_one(query,read="oracle")
except sqlglot.ParseError as p:
    print('Parsing error!')
    print(p)
except Exception as e:
    print(type(e))
    print(e)

Results:

py .\withfunctionerror.py
Parsing error!
Expecting (. Line 1, Col: 20.
  WITH FUNCTION f_demo(v_in_ch IN CHAR) RETURN CHAR
IS
BEGIN
    RETURN v_in_ch;
END;

SELECT
    'C' || f_demo('d')
FROM 

Query runs fine producing output 'Cd' under Oracle 19c

[georgesittas]

Hey, thanks for the report, but this is low priority for the core team. Happy to accept a well-crafted, documented & tested PR. If you do tackle this, make sure to check other dialects and isolate it in Oracle if needed, IIRC Trino has a similar WITH FUNCTION syntax and we probably don't want the new logic to be used for it.

[graymcd]

Cool, I totally get that. Thanks for the update.