Highlight C Library Code Examples

[wervin]

Hi everyone,

First of all, thank you for this library – it's amazing! 😄

Currently, I'm having difficulties using the highlight library in C... Do you have any examples?

Below is my non-working code 😭 . Any help is appreciated!

extern const TSLanguage *tree_sitter_json(void);

void _test(void)
{
    const char source_code[] = "[1, null]";
    
    const char highlight_query[] = "(pair\n"
                                   "key: (_) @string.special.key)\n"
                                   "(string) @string\n"
                                   "(number) @number\n"
                                   "[\n"
                                   "    (null)\n"
                                   "    (true)\n"
                                   "    (false)\n"
                                   "] @constant.builtin\n"
                                   "(escape_sequence) @escape\n"
                                   "(comment) @comment";

    const char regex[] = "{\n"
                         "  \"tree-sitter\": [\n"
                         "    {\n"
                         "      \"scope\": \"source.json\",\n"
                         "      \"file-types\": [\n"
                         "        \"json\"\n"
                         "      ]\n"
                         "    }\n"
                         "  ]\n"
                         "}\n";

    const char *highlight_names[] = {"number"};
    const char *attribute_strings[] = {"red"};

    TSHighlighter *highlighter = ts_highlighter_new(highlight_names, attribute_strings, 1);

    ts_highlighter_add_language(highlighter, "source.json", regex, tree_sitter_json(), highlight_query, NULL, NULL, sizeof(highlight_query), 0, 0);

    TSHighlightBuffer *buffer = ts_highlight_buffer_new();

    ts_highlighter_highlight(highlighter, "source.json", source_code, sizeof(source_code), buffer, 0);

    printf("buffer length: %u\n", ts_highlight_buffer_len(buffer));
    printf("%s\n", ts_highlight_buffer_content(buffer));

    ts_highlight_buffer_delete(buffer);
    ts_highlighter_delete(highlighter);
}

[wervin]

Okay, I should have verified whether ts_highlighter_add_language returned an error, that should provide the answer. And now, it works! 😄

extern const TSLanguage *tree_sitter_json(void);

void _test(void)
{
    const char source_code[] = "[1, null]";
    
    const char highlight_query[] = "(number) @number";

    const char *highlight_names[] = {"number"};
    const char *attribute_strings[] = {"red"};

    TSHighlighter *highlighter = ts_highlighter_new(highlight_names, attribute_strings, 1);

    ts_highlighter_add_language(highlighter, "source.json", NULL, tree_sitter_json(), highlight_query, NULL, NULL, sizeof(highlight_query) - 1, 0, 0);

    TSHighlightBuffer *buffer = ts_highlight_buffer_new();

    ts_highlighter_highlight(highlighter, "source.json", source_code, sizeof(source_code), buffer, 0);

    const uint8_t *raw = ts_highlight_buffer_content(buffer);
    printf("%s\n", raw);

    ts_highlight_buffer_delete(buffer);
    ts_highlighter_delete(highlighter);
}