risingwave_expr_impl/table_function/
pg_get_keywords.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use risingwave_expr::function;
16use risingwave_sqlparser::keywords::{
17    ALL_KEYWORDS_INDEX, RESERVED_FOR_COLUMN_ALIAS, RESERVED_FOR_COLUMN_OR_TABLE_NAME,
18};
19
20/// Returns a set of records describing the SQL keywords recognized by the server.
21///
22/// The word column contains the keyword.
23///
24/// The catcode column contains a category code:
25/// - U for an unreserved keyword
26/// - C for a keyword that can be a column name
27/// - T for a keyword that can be a type or function name
28/// - R for a fully reserved keyword.
29///
30/// The catdesc column contains a possibly-localized string describing the keyword's category.
31///
32/// ```slt
33/// query TTT
34/// select * from pg_get_keywords() where word = 'add';
35/// ----
36/// add U unreserved
37/// ```
38#[function("pg_get_keywords() -> setof struct<word varchar, catcode varchar, catdesc varchar>")]
39fn pg_get_keywords() -> impl Iterator<Item = (Box<str>, &'static str, &'static str)> {
40    ALL_KEYWORDS_INDEX.iter().map(|keyword| {
41        // FIXME: The current category is not correct. Many are different from the PostgreSQL.
42        let catcode = if !RESERVED_FOR_COLUMN_OR_TABLE_NAME.contains(keyword) {
43            "U"
44        } else if !RESERVED_FOR_COLUMN_ALIAS.contains(keyword) {
45            "C"
46        } else {
47            "R"
48        };
49        let catdesc = match catcode {
50            "U" => "unreserved",
51            "C" => "unreserved (cannot be function or type name)",
52            "T" => "reserved (can be function or type name)",
53            "R" => "reserved",
54            _ => unreachable!(),
55        };
56        (keyword.to_string().to_lowercase().into(), catcode, catdesc)
57    })
58}
risingwave_expr_impl/table_function/pg_get_keywords.rs

risingwave_expr_impl/table_function/
pg_get_keywords.rs
