llama-chat : Add Yandex instruct model template support (#12621)

* add yandex template

* update yandex chat template

* fix tests

* adjust chat template

* fix style

* fix tool macro in template

* add clarify comment

---------

Co-authored-by: Sergei Vorobev <serv01@yandex-team.ru>
Co-authored-by: Xuan-Son Nguyen <thichthat@gmail.com>

src/llama-chat.cpp

@@ -59,6 +59,7 @@ static const std::map<std::string, llm_chat_template> LLM_CHAT_TEMPLATES = {
     { "granite",           LLM_CHAT_TEMPLATE_GRANITE           },
     { "gigachat",          LLM_CHAT_TEMPLATE_GIGACHAT          },
     { "megrez",            LLM_CHAT_TEMPLATE_MEGREZ            },
+    { "yandex",            LLM_CHAT_TEMPLATE_YANDEX            },
 };
 
 llm_chat_template llm_chat_template_from_str(const std::string & name) {
@@ -168,6 +169,8 @@ llm_chat_template llm_chat_detect_template(const std::string & tmpl) {
         return LLM_CHAT_TEMPLATE_GIGACHAT;
     } else if (tmpl_contains("<|role_start|>")) {
         return LLM_CHAT_TEMPLATE_MEGREZ;
+    } else if (tmpl_contains(" Ассистент:")) {
+        return LLM_CHAT_TEMPLATE_YANDEX;
     }
     return LLM_CHAT_TEMPLATE_UNKNOWN;
 }
@@ -567,6 +570,24 @@ int32_t llm_chat_apply_template(
         if (add_ass) {
             ss << "<|role_start|>assistant<|role_end|>";
         }
+    } else if (tmpl == LLM_CHAT_TEMPLATE_YANDEX) {
+        // Yandex template ("\n\n" is defined as EOT token)
+
+        ss << "<s>";
+
+        for (size_t i = 0; i < chat.size(); i++) {
+            std::string role(chat[i]->role);
+            if (role == "user") {
+                ss << " Пользователь: " << chat[i]->content << "\n\n";
+            } else if (role == "assistant") {
+                ss << " Ассистент: " << chat[i]->content << "\n\n";
+            }
+        }
+
+        // Add generation prompt if needed
+        if (add_ass) {
+            ss << " Ассистент:[SEP]";
+        }
     } else {
         // template not supported
         return -1;
@@ -585,4 +606,3 @@ int32_t llama_chat_builtin_templates(const char ** output, size_t len) {
     }
     return (int32_t) LLM_CHAT_TEMPLATES.size();
 }
-

src/llama-chat.h

@@ -38,6 +38,7 @@ enum llm_chat_template {
     LLM_CHAT_TEMPLATE_GRANITE,
     LLM_CHAT_TEMPLATE_GIGACHAT,
     LLM_CHAT_TEMPLATE_MEGREZ,
+    LLM_CHAT_TEMPLATE_YANDEX,
     LLM_CHAT_TEMPLATE_UNKNOWN,
 };