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, GenericDialect, dialect_from_str},
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 =
42            dialect_from_str(dialect).unwrap_or_else(|| Box::new(GenericDialect {}));
43        Self { dialect }
44    }
45}
46
47pub struct NoSyntaxHighlighter {}
48
49impl Highlighter for NoSyntaxHighlighter {}
50
51impl Highlighter for SyntaxHighlighter {
52    fn highlight<'l>(&self, line: &'l str, _: usize) -> Cow<'l, str> {
53        let mut out_line = String::new();
54
55        // `with_unescape(false)` since we want to rebuild the original string.
56        let mut tokenizer =
57            Tokenizer::new(self.dialect.as_ref(), line).with_unescape(false);
58        let tokens = tokenizer.tokenize();
59        match tokens {
60            Ok(tokens) => {
61                for token in tokens.iter() {
62                    match token {
63                        Token::Word(w) if w.keyword != Keyword::NoKeyword => {
64                            out_line.push_str(&Color::red(token));
65                        }
66                        Token::SingleQuotedString(_) => {
67                            out_line.push_str(&Color::green(token));
68                        }
69                        other => out_line.push_str(&format!("{other}")),
70                    }
71                }
72                out_line.into()
73            }
74            Err(_) => Borrowed(line),
75        }
76    }
77
78    fn highlight_char(&self, line: &str, _pos: usize, _cmd: CmdKind) -> bool {
79        !line.is_empty()
80    }
81}
82
83/// Convenient utility to return strings with [ANSI color](https://gist.github.com/JBlond/2fea43a3049b38287e5e9cefc87b2124).
84pub(crate) struct Color {}
85
86impl Color {
87    pub(crate) fn green(s: impl Display) -> String {
88        format!("\x1b[92m{s}\x1b[0m")
89    }
90
91    pub(crate) fn red(s: impl Display) -> String {
92        format!("\x1b[91m{s}\x1b[0m")
93    }
94
95    pub(crate) fn gray(s: impl Display) -> String {
96        format!("\x1b[90m{s}\x1b[0m")
97    }
98}
99
100#[cfg(test)]
101mod tests {
102    use super::SyntaxHighlighter;
103    use super::config::Dialect;
104    use rustyline::highlight::Highlighter;
105
106    #[test]
107    fn highlighter_valid() {
108        let s = "SElect col_a from tab_1;";
109        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
110        let out = highlighter.highlight(s, s.len());
111        assert_eq!(
112            "\u{1b}[91mSElect\u{1b}[0m col_a \u{1b}[91mfrom\u{1b}[0m tab_1;",
113            out
114        );
115    }
116
117    #[test]
118    fn highlighter_valid_with_new_line() {
119        let s = "SElect col_a from tab_1\n WHERE col_b = 'なにか';";
120        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
121        let out = highlighter.highlight(s, s.len());
122        assert_eq!(
123            "\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;",
124            out
125        );
126    }
127
128    #[test]
129    fn highlighter_invalid() {
130        let s = "SElect col_a from tab_1 WHERE col_b = ';";
131        let highlighter = SyntaxHighlighter::new(&Dialect::Generic);
132        let out = highlighter.highlight(s, s.len());
133        assert_eq!("SElect col_a from tab_1 WHERE col_b = ';", out);
134    }
135}
datafusion_cli/highlighter.rs

datafusion_cli/
highlighter.rs
