grammar : restore llama_grammar_accept signature

ggml-ci

examples/gbnf-validator/gbnf-validator.cpp

@@ -12,24 +12,24 @@ static bool llama_grammar_validate(struct llama_grammar * grammar, const std::st
     const auto cpts = unicode_cpts_from_utf8(input_str);
 
     const llama_grammar_rules  & rules      = llama_grammar_get_rules (grammar);
-          llama_grammar_stacks & cur_stacks = llama_grammar_get_stacks(grammar);
+          llama_grammar_stacks & stacks_cur = llama_grammar_get_stacks(grammar);
 
     size_t pos = 0;
     for (const auto & cpt : cpts) {
-        const llama_grammar_stacks prev_stacks = llama_grammar_get_stacks(grammar); // copy
+        const llama_grammar_stacks stacks_prev = llama_grammar_get_stacks(grammar); // copy
 
-        cur_stacks = llama_grammar_accept(rules, prev_stacks, cpt);
+        llama_grammar_accept(rules, stacks_prev, cpt, stacks_cur);
 
-        if (cur_stacks.empty()) {
+        if (stacks_cur.empty()) {
             error_pos = pos;
             error_msg = "Unexpected character '" + unicode_cpt_to_utf8(cpt) + "'";
-            cur_stacks = prev_stacks;
+            stacks_cur = stacks_prev;
             return false;
         }
         ++pos;
     }
 
-    for (const auto & stack : cur_stacks) {
+    for (const auto & stack : stacks_cur) {
         if (stack.empty()) {
             return true;
         }

src/llama-grammar.cpp

@@ -822,12 +822,13 @@ llama_grammar_stacks & llama_grammar_get_stacks(struct llama_grammar * grammar)
     return grammar->stacks;
 }
 
-llama_grammar_stacks llama_grammar_accept(
+void llama_grammar_accept(
         const llama_grammar_rules  & rules,
         const llama_grammar_stacks & stacks,
-        const uint32_t               chr) {
-    llama_grammar_stacks result;
-    result.reserve(stacks.size());
+        const uint32_t               chr,
+              llama_grammar_stacks & stacks_new) {
+    stacks_new.clear();
+    stacks_new.reserve(stacks.size());
 
     for (const auto & stack : stacks) {
         if (stack.empty()) {
@@ -843,11 +844,9 @@ llama_grammar_stacks llama_grammar_accept(
             if (!llama_grammar_is_end_of_sequence(pos)) {
                 new_stack.push_back(pos);
             }
-            llama_grammar_advance_stack(rules, new_stack, result);
+            llama_grammar_advance_stack(rules, new_stack, stacks_new);
         }
     }
-
-    return result;
 }
 
 llama_grammar_candidates llama_grammar_reject_candidates_for_stack(
@@ -1127,9 +1126,11 @@ void llama_grammar_accept_impl(struct llama_grammar & grammar, llama_token token
     const auto   decoded     = decode_utf8(piece, grammar.partial_utf8);
     const auto & code_points = decoded.first;
 
+    llama_grammar_stacks stacks_new;
+
     for (auto it = code_points.begin(), end = code_points.end() - 1; it != end; ++it) {
-        llama_grammar_stacks new_stacks = llama_grammar_accept(grammar.rules, grammar.stacks, *it);
-        grammar.stacks = std::move(new_stacks);
+        llama_grammar_accept(grammar.rules, grammar.stacks, *it, stacks_new);
+        grammar.stacks = std::move(stacks_new);
     }
 
     grammar.partial_utf8 = decoded.second;

src/llama-grammar.h

@@ -65,10 +65,11 @@ const llama_grammar_rules  & llama_grammar_get_rules (const struct llama_grammar
 // be positioned at a character range (see `llama_grammar_advance_stack`), and
 // produces the N possible stacks if the given char is accepted at those
 // positions
-llama_grammar_stacks llama_grammar_accept(
+void llama_grammar_accept(
         const llama_grammar_rules  & rules,
         const llama_grammar_stacks & stacks,
-                          uint32_t   chr);
+                          uint32_t   chr,
+              llama_grammar_stacks & stacks_new);
 
 std::vector<llama_grammar_candidate> llama_grammar_reject_candidates_for_stack(
         const llama_grammar_rules      & rules,

tests/test-grammar-integration.cpp

@@ -33,20 +33,20 @@ static bool match_string(const std::string & input, llama_grammar * grammar) {
     const auto cpts = unicode_cpts_from_utf8(input);
 
     const llama_grammar_rules  & rules      = llama_grammar_get_rules (grammar);
-          llama_grammar_stacks & cur_stacks = llama_grammar_get_stacks(grammar);
+          llama_grammar_stacks & stacks_cur = llama_grammar_get_stacks(grammar);
 
     for (const auto & cpt : cpts) {
-        const llama_grammar_stacks prev_stacks = llama_grammar_get_stacks(grammar); // copy
+        const llama_grammar_stacks stacks_prev = llama_grammar_get_stacks(grammar); // copy
 
-        cur_stacks = llama_grammar_accept(rules, prev_stacks, cpt);
+        llama_grammar_accept(rules, stacks_prev, cpt, stacks_cur);
 
-        if (cur_stacks.empty()) {
+        if (stacks_cur.empty()) {
             // no stacks means that the grammar failed to match at this point
             return false;
         }
     }
 
-    for (const auto & stack : cur_stacks) {
+    for (const auto & stack : stacks_cur) {
         if (stack.empty()) {
             // An empty stack means that the grammar has been completed
             return true;
@@ -63,9 +63,9 @@ static void test(const std::string & test_desc, const std::string & grammar_str,
     auto * grammar = build_grammar(grammar_str);
 
     // Save the original grammar stacks so that we can reset after every new string we want to test
-    const llama_grammar_stacks original_stacks = llama_grammar_get_stacks(grammar);
+    const llama_grammar_stacks stacks_org = llama_grammar_get_stacks(grammar);
 
-    llama_grammar_stacks & cur_stacks = llama_grammar_get_stacks(grammar);
+    llama_grammar_stacks & stacks_cur = llama_grammar_get_stacks(grammar);
 
     fprintf(stderr, "  🔵 Valid strings:\n");
 
@@ -102,7 +102,7 @@ static void test(const std::string & test_desc, const std::string & grammar_str,
         assert(matched);
 
         // Reset the grammar stacks
-        cur_stacks = original_stacks;
+        stacks_cur = stacks_org;
     }
 
     fprintf(stderr, "  🟠 Invalid strings:\n");
@@ -122,7 +122,7 @@ static void test(const std::string & test_desc, const std::string & grammar_str,
         assert(!matched);
 
         // Reset the grammar stacks
-        cur_stacks = original_stacks;
+        stacks_cur = stacks_org;
     }
 
     // Clean up allocated memory