tpnote_lib/
highlight.rs

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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
//! Syntax highlighting for (inline) source code blocks in Markdown input.

use crate::config::LIB_CFG;
use pulldown_cmark::{CodeBlockKind, Event, Tag, TagEnd};
use syntect::highlighting::ThemeSet;
use syntect::html::css_for_theme_with_class_style;
use syntect::html::{ClassStyle, ClassedHTMLGenerator};
use syntect::parsing::SyntaxSet;
use syntect::util::LinesWithEndings;

/// Get the viewer syntax highlighting CSS configuration.
pub(crate) fn get_viewer_highlighting_css() -> String {
    let lib_cfg = LIB_CFG.read_recursive();
    let ts = ThemeSet::load_defaults();

    let theme_name = &lib_cfg.tmpl_html.viewer_highlighting_theme;
    ts.themes
        .get(theme_name)
        .and_then(|theme| {
            css_for_theme_with_class_style(theme, syntect::html::ClassStyle::Spaced).ok()
        })
        .unwrap_or_default()
}

/// Get the exporter syntax highlighting CSS configuration.
pub(crate) fn get_exporter_highlighting_css() -> String {
    let lib_cfg = LIB_CFG.read_recursive();
    let ts = ThemeSet::load_defaults();

    let theme_name = &lib_cfg.tmpl_html.exporter_highlighting_theme;
    ts.themes
        .get(theme_name)
        .and_then(|theme| {
            css_for_theme_with_class_style(theme, syntect::html::ClassStyle::Spaced).ok()
        })
        .unwrap_or_default()
}

/// A wraper for a `pulldown_cmark` event iterator.
#[derive(Debug, Default)]
pub struct SyntaxPreprocessor<'a, I: Iterator<Item = Event<'a>>> {
    parent: I,
}

/// Constructor.
impl<'a, I: Iterator<Item = Event<'a>>> SyntaxPreprocessor<'a, I> {
    pub fn new(parent: I) -> Self {
        Self { parent }
    }
}

/// Implement `Iterator` for wrapper `SyntaxPreprocessor`.
impl<'a, I: Iterator<Item = Event<'a>>> Iterator for SyntaxPreprocessor<'a, I> {
    type Item = Event<'a>;

    fn next(&mut self) -> Option<Self::Item> {
        // Detect inline LaTeX.
        let lang = match self.parent.next()? {
            Event::Start(Tag::CodeBlock(CodeBlockKind::Fenced(lang))) if !lang.is_empty() => lang,
            // This is the deprecheated inline math syntax.
            // It is kept here for backwards compatibility.
            Event::Code(c) if c.len() > 1 && c.starts_with('$') && c.ends_with('$') => {
                return Some(Event::Html(
                    latex2mathml::latex_to_mathml(
                        &c[1..c.len() - 1],
                        latex2mathml::DisplayStyle::Inline,
                    )
                    .unwrap_or_else(|e| e.to_string())
                    .into(),
                ));
            }
            Event::InlineMath(c) => {
                return Some(Event::Html(
                    latex2mathml::latex_to_mathml(c.as_ref(), latex2mathml::DisplayStyle::Inline)
                        .unwrap_or_else(|e| e.to_string())
                        .into(),
                ));
            }
            Event::DisplayMath(c) => {
                return Some(Event::Html(
                    latex2mathml::latex_to_mathml(c.as_ref(), latex2mathml::DisplayStyle::Block)
                        .unwrap_or_else(|e| e.to_string())
                        .into(),
                ));
            }
            other => return Some(other),
        };

        let mut code = String::new();
        let mut event = self.parent.next();
        while let Some(Event::Text(ref code_block)) = event {
            code.push_str(code_block);
            event = self.parent.next();
        }

        debug_assert!(matches!(event, Some(Event::End(TagEnd::CodeBlock))));

        if lang.as_ref() == "math" {
            return Some(Event::Html(
                latex2mathml::latex_to_mathml(&code, latex2mathml::DisplayStyle::Block)
                    .unwrap_or_else(|e| e.to_string())
                    .into(),
            ));
        }

        let mut html = String::with_capacity(code.len() + code.len() * 3 / 2 + 20);

        // Use default syntax styling.
        let ss = SyntaxSet::load_defaults_newlines();
        let sr = match ss.find_syntax_by_token(lang.as_ref()) {
            Some(sr) => {
                html.push_str("<pre><code class=\"language-");
                html.push_str(lang.as_ref());
                html.push_str("\">");
                sr
            }
            None => {
                log::debug!(
                    "renderer: no syntax definition found for: `{}`",
                    lang.as_ref()
                );
                html.push_str("<pre><code>");
                ss.find_syntax_plain_text()
            }
        };
        let mut html_generator =
            ClassedHTMLGenerator::new_with_class_style(sr, &ss, ClassStyle::Spaced);
        for line in LinesWithEndings::from(&code) {
            html_generator
                .parse_html_for_line_which_includes_newline(line)
                .unwrap_or_default();
        }
        html.push_str(html_generator.finalize().as_str());

        html.push_str("</code></pre>");

        Some(Event::Html(html.into()))
    }
}

#[cfg(test)]
mod test {
    use crate::highlight::SyntaxPreprocessor;
    use pulldown_cmark::{html, Options, Parser};

    #[test]
    fn test_latex_math() {
        // Inline math.
        let input: &str = "casual $\\sum_{n=0}^\\infty \\frac{1}{n!}$ text";

        let expected = "<p>casual <math xmlns=";

        let options = Options::all();
        let parser = Parser::new_ext(input, options);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        println!("Rendered: {}", rendered);
        assert!(rendered.starts_with(expected));

        //
        // Deprecheated inline math.
        // This code might be removed later.
        let input: &str = "casual `$\\sum_{n=0}^\\infty \\frac{1}{n!}$` text";

        let expected = "<p>casual <math xmlns=";

        let options = Options::all();
        let parser = Parser::new_ext(input, options);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert!(rendered.starts_with(expected));

        //
        // Block math 1
        let input = "text\n$$\nR(X, Y)Z = \\nabla_X\\nabla_Y Z - \
            \\nabla_Y \\nabla_X Z - \\nabla_{[X, Y]} Z\n$$";

        let expected = "<p>text\n\
            <math xmlns=\"http://www.w3.org/1998/Math/MathML\" display=\"block\">\
            <mi>R</mi><mo>(</mo><mi>X</mi><mo>,</mo><mi>Y</mi><mo>)</mo>\
            <mi>Z</mi><mo>=</mo><msub><mo>∇</mo><mi>X</mi></msub><msub><mo>∇</mo>\
            <mi>Y</mi></msub><mi>Z</mi><mo>-</mo><msub><mo>∇</mo><mi>Y</mi></msub>\
            <msub><mo>∇</mo><mi>X</mi></msub><mi>Z</mi><mo>-</mo><msub><mo>∇</mo>\
            <mrow><mo>[</mo><mi>X</mi><mo>,</mo><mi>Y</mi><mo>]</mo></mrow></msub>\
            <mi>Z</mi></math></p>\n";

        let options = Options::all();
        let parser = Parser::new_ext(input, options);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert_eq!(rendered, expected);

        // Block math 2
        let input = "text\n```math\nR(X, Y)Z = \\nabla_X\\nabla_Y Z - \
            \\nabla_Y \\nabla_X Z - \\nabla_{[X, Y]} Z\n```";

        let expected = "<p>text</p>\n\
            <math xmlns=\"http://www.w3.org/1998/Math/MathML\" display=\"block\">\
            <mi>R</mi><mo>(</mo><mi>X</mi><mo>,</mo><mi>Y</mi><mo>)</mo>\
            <mi>Z</mi><mo>=</mo><msub><mo>∇</mo><mi>X</mi></msub><msub><mo>∇</mo>\
            <mi>Y</mi></msub><mi>Z</mi><mo>-</mo><msub><mo>∇</mo><mi>Y</mi></msub>\
            <msub><mo>∇</mo><mi>X</mi></msub><mi>Z</mi><mo>-</mo><msub><mo>∇</mo>\
            <mrow><mo>[</mo><mi>X</mi><mo>,</mo><mi>Y</mi><mo>]</mo></mrow></msub>\
            <mi>Z</mi></math>";

        let options = Options::all();
        let parser = Parser::new_ext(input, options);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert_eq!(rendered, expected);
    }

    #[test]
    fn test_rust_source() {
        let input: &str = "```rust\n\
            fn main() {\n\
                println!(\"Hello, world!\");\n\
            }\n\
            ```";

        let expected = "<pre><code class=\"language-rust\">\
            <span class=\"source rust\">";

        let parser = Parser::new(input);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert!(rendered.starts_with(expected));
    }

    #[test]
    fn test_plain_text() {
        let input: &str = "```\nSome\nText\n```";

        let expected = "<pre><code>\
            Some\nText\n</code></pre>\n";

        let parser = Parser::new(input);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert_eq!(rendered, expected);
    }

    #[test]
    fn test_unkown_source() {
        let input: &str = "```abc\n\
            fn main() {\n\
                println!(\"Hello, world!\");\n\
            }\n\
            ```";

        let expected = "<pre><code>\
            <span class=\"text plain\">fn main()";

        let parser = Parser::new(input);
        let processed = SyntaxPreprocessor::new(parser);

        let mut rendered = String::new();
        html::push_html(&mut rendered, processed);
        assert!(rendered.starts_with(expected));
    }

    #[test]
    fn test_md() {
        let markdown_input = "# Titel\n\nBody";
        let expected = "<h1>Titel</h1>\n<p>Body</p>\n";

        let options = Options::all();
        let parser = Parser::new_ext(markdown_input, options);
        let parser = SyntaxPreprocessor::new(parser);

        // Write to String buffer.
        let mut html_output: String = String::with_capacity(markdown_input.len() * 3 / 2);
        html::push_html(&mut html_output, parser);
        assert_eq!(html_output, expected);
    }

    #[test]
    fn test_indented() {
        let markdown_input = r#"
1. test

   ```bash
   wget getreu.net
   echo test
   ```
"#;

        let expected = "<ol>\n<li>\n<p>test</p>\n<pre>\
            <code class=\"language-bash\">\
            <span class=\"source shell bash\">\
            <span class=\"meta function-call shell\">\
            <span class=\"variable function shell\">wget</span></span>";
        let options = Options::all();
        let parser = Parser::new_ext(markdown_input, options);
        let parser = SyntaxPreprocessor::new(parser);

        // Write to String buffer.
        let mut html_output: String = String::with_capacity(markdown_input.len() * 3 / 2);
        html::push_html(&mut html_output, parser);
        assert!(html_output.starts_with(expected));
    }
}