Function llama_sampler_init_grammar_impl

smallthinker/src/llama-sampling.cpp:1517–1570

};

static struct llama_sampler * llama_sampler_init_grammar_impl(
        const struct llama_vocab * vocab,
                      const char * grammar_str,
                      const char * grammar_root,
                              bool lazy,
                     const char ** trigger_words,
                            size_t num_trigger_words,
               const llama_token * trigger_tokens,
                            size_t num_trigger_tokens,
                     const char ** trigger_patterns,
                            size_t num_trigger_patterns) {
    auto * ctx = new llama_sampler_grammar;

    if (grammar_str != nullptr && grammar_str[0] != '\0') {
        // TODO: remove trigger_words support.
        if (trigger_words != nullptr && num_trigger_words > 0) {
            GGML_ASSERT(trigger_patterns == nullptr && num_trigger_patterns == 0);
            std::string trigger_pattern("[\\s\\S]*?(");
            for (size_t i = 0; i < num_trigger_words; ++i) {
                static const std::regex special_chars("[.^$|()*+?\\[\\]{}\\\\]");
                if (i > 0) {
                    trigger_pattern += "|";
                }
                trigger_pattern += std::regex_replace(trigger_words[i], special_chars, "\\$0");
            }
            trigger_pattern += ")[\\s\\S]*";
            auto trigger_pattern_c = trigger_pattern.c_str();
            trigger_patterns = &trigger_pattern_c;
            num_trigger_patterns = 1;
        }
        *ctx = {
            /* .vocab        = */ vocab,
            /* .grammar_str  = */ grammar_str,
            /* .grammar_root = */ grammar_root,
            /* .grammar      = */ llama_grammar_init_impl(vocab, grammar_str, grammar_root, lazy, trigger_patterns, num_trigger_patterns, trigger_tokens, num_trigger_tokens),
        };
        if (!ctx->grammar) {
            delete ctx;
            return nullptr;
        }
    } else {
        *ctx = {
            /* .vocab        = */ vocab,
            /* .grammar_str  = */ {},
            /* .grammar_root = */ {},
            /* .grammar      = */ nullptr,
        };
    }

    return llama_sampler_init(
        /* .iface = */ &llama_sampler_grammar_i,
        /* .ctx   = */ ctx
    );
}

struct llama_sampler * llama_sampler_init_grammar(
        const struct llama_vocab * vocab,