datafusion_cli/
highlighter.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18//! The syntax highlighter.
19
20use std::{
21    borrow::Cow::{self, Borrowed},
22    fmt::Display,
23};
24
25use datafusion::sql::sqlparser::{
26    dialect::{dialect_from_str, Dialect, GenericDialect},
27    keywords::Keyword,
28    tokenizer::{Token, Tokenizer},
29};
30use datafusion_common::config;
31use rustyline::highlight::{CmdKind, Highlighter};
32
33/// The syntax highlighter.
34#[derive(Debug)]
35pub struct SyntaxHighlighter {
36    dialect: Box<dyn Dialect>,
37}
38
39impl SyntaxHighlighter {
40    pub fn new(dialect: &config::Dialect) -> Self {
41        let dialect = dialect_from_str(dialect).unwrap_or(Box::new(GenericDialect {}));
42        Self { dialect }
43    }
44}
45
46pub struct NoSyntaxHighlighter {}
47
48impl Highlighter for NoSyntaxHighlighter {}
49
50impl Highlighter for SyntaxHighlighter {
51    fn highlight<'l>(&self, line: &'l str, _: usize) -> Cow<'l, str> {
52        let mut out_line = String::new();
53
54        // `with_unescape(false)` since we want to rebuild the original string.
55        let mut tokenizer =
56            Tokenizer::new(self.dialect.as_ref(), line).with_unescape(false);
57        let tokens = tokenizer.tokenize();
58        match tokens {
59            Ok(tokens) => {
60                for token in tokens.iter() {
61                    match token {
62                        Token::Word(w) if w.keyword != Keyword::NoKeyword => {
63                            out_line.push_str(&Color::red(token));
64                        }
65                        Token::SingleQuotedString(_) => {
66                            out_line.push_str(&Color::green(token));
67                        }
68                        other => out_line.push_str(&format!("{other}")),
69                    }
70                }
71                out_line.into()
72            }
73            Err(_) => Borrowed(line),
74        }
75    }
76
77    fn highlight_char(&self, line: &str, _pos: usize, _cmd: CmdKind) -> bool {
78        !line.is_empty()
79    }
80}
81
82/// Convenient utility to return strings with [ANSI color](https://gist.github.com/JBlond/2fea43a3049b38287e5e9cefc87b2124).
83struct Color {}
84
85impl Color {
86    fn green(s: impl Display) -> String {
87        format!("\x1b[92m{s}\x1b[0m")
88    }
89
90    fn red(s: impl Display) -> String {
91        format!("\x1b[91m{s}\x1b[0m")
92    }
93}
94
95#[cfg(test)]
96mod tests {
97    use super::config::Dialect;
98    use super::SyntaxHighlighter;
99    use rustyline::highlight::Highlighter;
100
101    #[test]
102    fn highlighter_valid() {
103        let s = "SElect col_a from tab_1;";
104        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
105        let out = highlighter.highlight(s, s.len());
106        assert_eq!(
107            "\u{1b}[91mSElect\u{1b}[0m col_a \u{1b}[91mfrom\u{1b}[0m tab_1;",
108            out
109        );
110    }
111
112    #[test]
113    fn highlighter_valid_with_new_line() {
114        let s = "SElect col_a from tab_1\n WHERE col_b = 'なにか';";
115        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
116        let out = highlighter.highlight(s, s.len());
117        assert_eq!(
118            "\u{1b}[91mSElect\u{1b}[0m col_a \u{1b}[91mfrom\u{1b}[0m tab_1\n \u{1b}[91mWHERE\u{1b}[0m col_b = \u{1b}[92m'なにか'\u{1b}[0m;",
119            out
120        );
121    }
122
123    #[test]
124    fn highlighter_invalid() {
125        let s = "SElect col_a from tab_1 WHERE col_b = ';";
126        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
127        let out = highlighter.highlight(s, s.len());
128        assert_eq!("SElect col_a from tab_1 WHERE col_b = ';", out);
129    }
130}
datafusion_cli/highlighter.rs

datafusion_cli/
highlighter.rs
