1 files changed, 19 insertions, 0 deletions
diff --git a/llama.cpp b/llama.cpp
index b9485df0..edf3b4ea 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -3850,6 +3850,25 @@ void llama_grammar_free(struct llama_grammar * grammar) {
     delete grammar;
 }
 
+struct llama_grammar * llama_grammar_copy(const struct llama_grammar * grammar) {
+    llama_grammar * result = new llama_grammar{ grammar->rules, grammar->stacks, grammar->partial_utf8 };
+
+    // redirect elements in stacks to point to new rules
+    for (size_t is = 0; is < result->stacks.size(); is++) {
+        for (size_t ie = 0; ie < result->stacks[is].size(); ie++) {
+            for (size_t ir0 = 0; ir0 < grammar->rules.size(); ir0++) {
+                for (size_t ir1 = 0; ir1 < grammar->rules[ir0].size(); ir1++) {
+                    if (grammar->stacks[is][ie] == &grammar->rules[ir0][ir1]) {
+                         result->stacks[is][ie]  =  &result->rules[ir0][ir1];
+                    }
+                }
+            }
+        }
+    }
+
+    return result;
+}
+
 //
 // sampling
 //