tree-sitter is blocking

[juli1]

Problem

Tree-sitter is blocking when iterating on the results of a rule for Java. This is happening only with some queries.

Added a fully reproducible example for Java.

Steps to reproduce

git clone https://github.com/juli1/tree-sitter-debug
cd tree-sitter-debug
cargo run

Expected behavior

The program should finish.

Tree-sitter version (tree-sitter --version)

tree-sitter 0.22.2

Operating system/version

macOS

[WillLillis]

Tree-sitter's playground becomes unresponsive after attempting to scroll the source code box (query box is fine, syntax tree stutters a bit but also scrolls up and down) past a certain point with the same code/ query:

EDIT: I ran the same query with the same source code overnight using the C API and it finished with a total of 307,383 matches iterated through. So it looks like there isn't a bug, but just a lot of matches?

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <tree_sitter/api.h>

const TSLanguage *tree_sitter_java(void);

int main() {
    // Create a parser.
    TSParser *parser = ts_parser_new();

    // Set the parser's language (JSON in this case).
    ts_parser_set_language(parser, tree_sitter_java());

    // Build a syntax tree based on source code stored in a string.
    const char *source_code =
                              "\n"
                              "/*\n"
                              " * Graphics2D Tester\n"
                              /** Rest of source code here... **/
                              "            this.single = single;\n"
                              "        }\n"
                              "    }\n"
                              "\n"
                              "}\n"
                              "";
    TSTree *tree =
        ts_parser_parse_string(parser, NULL, source_code, strlen(source_code));

    if (tree == NULL) {
        perror("tree is NULL\n");
    }

    // Get the root node of the syntax tree.
    TSNode root_node = ts_tree_root_node(tree);

    const char *query_source = "(block\n"
                               "    (local_variable_declaration\n"
                               "        type: (type_identifier) @type\n"
                               "        declarator: (variable_declarator\n"
                               "            name: (identifier) @varname\n"
                               "        )\n"
                               "\n"
                               "    ) @decl\n"
                               "    (_)*\n"
                               "    (expression_statement\n"
                               "        (method_invocation\n"
                               "            object: (identifier) @object1\n"
                               "            name: (identifier) @name1\n"
                               "        )\n"
                               "\n"
                               "    )? @defaulttyping\n"
                               "    (_)*\n"
                               "    (expression_statement\n"
                               "        (method_invocation\n"
                               "            object: (identifier) @object2\n"
                               "            name: (identifier) @name2\n"
                               "        )\n"
                               "\n"
                               "    )\n"
                               "    (#eq? @object1 @varname)\n"
                               "    (#eq? @name1 \"enableDefaultTyping\")\n"
                               "    (#eq? @type \"ObjectMapper\")\n"
                               "    (#eq? @object2 @varname)\n"
                               "    (#eq? @name2 \"readValue\")\n"
                               ")";

    uint32_t err_offset;
    TSQueryError err_type;
    TSQuery *query = ts_query_new(tree_sitter_java(), query_source,
                                  strlen(query_source), &err_offset, &err_type);
    if (query == NULL) {
        perror("query is NULL\n");
    }
    if (err_type != 0) {
        perror("query construction error\n");
    }
    TSQueryCursor *cursor = ts_query_cursor_new();
    if (cursor == NULL) {
        perror("cursor is NULL\n");
    }
    ts_query_cursor_exec(cursor, query, root_node);

    TSQueryMatch match;
    uintmax_t count = 0;
    while (ts_query_cursor_next_match(cursor, &match)) {
        // printf("%zu id: %u, pattern_index: %hu, capture_count: %hu\n", count++,
        //        match.id, match.pattern_index, match.capture_count);
        printf("Count: %zu\n", count++);
                
    }

    // Free all of the heap-allocated memory.
    ts_tree_delete(tree);
    ts_parser_delete(parser);
    ts_query_delete(query);
    return 0;
}