**Use case**
`SELECT POSITION('/' IN s) FROM (SELECT 'Hello/World' AS s);`

The same as `position(s, '/')`

"CROSS",
    "JOIN",
    "GLOBAL",
    "ANY",
    "ALL",
    "ASOF",
    "SEMI",
    "ANTI",
    "ONLY", 
    "ON",
    "USING",
    "PREWHERE",
    "WHERE",
    "GROUP",
    "WITH",
    "HAVING",
    "ORDER",
    "LIMIT",
    "OFFSET",
    "SETTINGS",
    "FORMAT",
    "UNION",
    "INTO",
    "NOT",
    "BETWEEN",
    "LIKE",
    "ILIKE",
    nullptr
};
bool ParserAlias::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)