1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

use tree_sitter_highlight::{HighlightConfiguration, HighlightEvent, Highlighter};

/// The listo of supported languages
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum Language {
    Rust,
    Javascript,
    Python,
    Cpp,
    Java,
}

/// The recognized highlight names, map them to hex colors in a hashmap to create a theme.
pub static HIGHLIGHT_NAMES: &[&str] = &[
    "attribute",
    "label",
    "constant",
    "function.builtin",
    "function.macro",
    "function",
    "keyword",
    "operator",
    "property",
    "punctuation",
    "punctuation.bracket",
    "punctuation.delimiter",
    "string",
    "string.special",
    "tag",
    "escape",
    "type",
    "type.builtin",
    "constructor",
    "variable",
    "variable.builtin",
    "variable.parameter",
    "comment",
];

/// If prepend class is none, then glowtree will be used.
pub fn highlight_to_html(lang: Language, code: &str) -> String {
    let recognized_names: Vec<String> = HIGHLIGHT_NAMES.iter().cloned().map(String::from).collect();

    let mut highlighter = Highlighter::new();

    let mut config = {
        match lang {
            Language::Rust => HighlightConfiguration::new(
                tree_sitter_rust::language(),
                tree_sitter_rust::HIGHLIGHT_QUERY,
                "",
                "",
            )
            .unwrap(),
            Language::Java => HighlightConfiguration::new(
                tree_sitter_java::language(),
                tree_sitter_java::HIGHLIGHT_QUERY,
                "",
                "",
            )
            .unwrap(),
            Language::Javascript => HighlightConfiguration::new(
                tree_sitter_javascript::language(),
                tree_sitter_javascript::HIGHLIGHT_QUERY,
                tree_sitter_javascript::INJECTION_QUERY,
                "",
            )
            .unwrap(),
            Language::Python => HighlightConfiguration::new(
                tree_sitter_python::language(),
                tree_sitter_python::HIGHLIGHT_QUERY,
                "",
                "",
            )
            .unwrap(),
            Language::Cpp => HighlightConfiguration::new(
                tree_sitter_cpp::language(),
                tree_sitter_cpp::HIGHLIGHT_QUERY,
                "",
                "",
            )
            .unwrap(),
        }
    };

    config.configure(&recognized_names);

    let mut result = String::new();

    let highlights = highlighter
        .highlight(&config, code.as_bytes(), None, |_| None)
        .unwrap();

    for event in highlights {
        match event.unwrap() {
            HighlightEvent::Source { start, end } => {
                result.push_str(code.get(start..end).unwrap());
            }
            HighlightEvent::HighlightStart(s) => {
                let name = HIGHLIGHT_NAMES.get(s.0).unwrap().replace(".", "-");

                result.push_str(&format!("<span class='{}'>", name));
            }
            HighlightEvent::HighlightEnd => {
                result.push_str("</span>");
            }
        }
    }

    result
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn it_works() {
        let code = r#"
use tree_sitter::Parser;
use tree_sitter_highlight::{HighlightConfiguration, HighlightEvent, Highlighter};
use thiserror::Error;

#[derive(Error, Debug)]
pub enum ResponseError {
    /// A paypal api error.
    #[error("api error {0}")]
    ApiError(#[from] PaypalError),
    /// A http error.
    #[error("http error {0}")]
    HttpError(#[from] reqwest::Error)
}
"#;

        let result = highlight_to_html(Language::Rust, code);
        println!("{}", result);
    }
}