Function llama_grammar_validate

smallthinker/tests/test-gbnf-validator.cpp:11–37

#include <vector>

static bool llama_grammar_validate(struct llama_grammar * grammar, const std::string & input_str, size_t & error_pos, std::string & error_msg) {
    const auto cpts = unicode_cpts_from_utf8(input_str);

    auto & stacks_cur = llama_grammar_get_stacks(grammar);

    size_t pos = 0;
    for (const auto & cpt : cpts) {
        llama_grammar_accept(grammar, cpt);

        if (stacks_cur.empty()) {
            error_pos = pos;
            error_msg = "Unexpected character '" + unicode_cpt_to_utf8(cpt) + "'";
            return false;
        }
        ++pos;
    }

    for (const auto & stack : stacks_cur) {
        if (stack.empty()) {
            return true;
        }
    }

    error_pos = pos;
    error_msg = "Unexpected end of input";
    return false;
}

static void print_error_message(const std::string & input_str, size_t error_pos, const std::string & error_msg) {
    fprintf(stdout, "Input string is invalid according to the grammar.\n");