diff --git a/common/chat.cpp b/common/chat.cpp
index e129581fd2f..a2ef6a22ce2 100644
--- a/common/chat.cpp
+++ b/common/chat.cpp
@@ -1758,23 +1758,12 @@ common_chat_msg common_chat_peg_parse(const common_peg_arena & src_pars
auto result = parser.parse(ctx);
if (result.fail()) {
- // During partial parsing, return partial results if any AST nodes were captured
- // This allows streaming to work correctly for formats like FUNC_MARKDOWN_CODE_BLOCK
- if (is_partial && result.end > 0) {
- // Try to extract any partial results from what was successfully parsed
- common_chat_msg msg;
- msg.role = "assistant";
- auto mapper = common_chat_peg_mapper(msg);
- mapper.from_ast(ctx.ast, result);
-
- if (ctx.is_debug()) {
- fprintf(stderr, "\nAST for partial parse (fail):\n%s\n", ctx.ast.dump().c_str());
- fflush(stderr);
- }
- return msg;
+ if (result.end == 0) {
+ throw std::runtime_error(std::string("Failed to parse input at pos ") + std::to_string(result.end) + ": " +
+ effective_input.substr(result.end));
}
- throw std::runtime_error(std::string("Failed to parse input at pos ") + std::to_string(result.end) + ": " +
- input.substr(result.end));
+ LOG_WRN("%s: parser failed at pos %zu, returning partial result. Unparsed: %s\n",
+ __func__, result.end, effective_input.substr(result.end).c_str());
}
common_chat_msg msg;
diff --git a/models/templates/Qwen-Qwen3.5-0.8B.jinja b/models/templates/Qwen-Qwen3.5-0.8B.jinja
new file mode 100644
index 00000000000..0ef09f214ea
--- /dev/null
+++ b/models/templates/Qwen-Qwen3.5-0.8B.jinja
@@ -0,0 +1,154 @@
+{%- set image_count = namespace(value=0) %}
+{%- set video_count = namespace(value=0) %}
+{%- macro render_content(content, do_vision_count, is_system_content=false) %}
+ {%- if content is string %}
+ {{- content }}
+ {%- elif content is iterable and content is not mapping %}
+ {%- for item in content %}
+ {%- if 'image' in item or 'image_url' in item or item.type == 'image' %}
+ {%- if is_system_content %}
+ {{- raise_exception('System message cannot contain images.') }}
+ {%- endif %}
+ {%- if do_vision_count %}
+ {%- set image_count.value = image_count.value + 1 %}
+ {%- endif %}
+ {%- if add_vision_id %}
+ {{- 'Picture ' ~ image_count.value ~ ': ' }}
+ {%- endif %}
+ {{- '<|vision_start|><|image_pad|><|vision_end|>' }}
+ {%- elif 'video' in item or item.type == 'video' %}
+ {%- if is_system_content %}
+ {{- raise_exception('System message cannot contain videos.') }}
+ {%- endif %}
+ {%- if do_vision_count %}
+ {%- set video_count.value = video_count.value + 1 %}
+ {%- endif %}
+ {%- if add_vision_id %}
+ {{- 'Video ' ~ video_count.value ~ ': ' }}
+ {%- endif %}
+ {{- '<|vision_start|><|video_pad|><|vision_end|>' }}
+ {%- elif 'text' in item %}
+ {{- item.text }}
+ {%- else %}
+ {{- raise_exception('Unexpected item type in content.') }}
+ {%- endif %}
+ {%- endfor %}
+ {%- elif content is none or content is undefined %}
+ {{- '' }}
+ {%- else %}
+ {{- raise_exception('Unexpected content type.') }}
+ {%- endif %}
+{%- endmacro %}
+{%- if not messages %}
+ {{- raise_exception('No messages provided.') }}
+{%- endif %}
+{%- if tools and tools is iterable and tools is not mapping %}
+ {{- '<|im_start|>system\n' }}
+ {{- "# Tools\n\nYou have access to the following functions:\n\n" }}
+ {%- for tool in tools %}
+ {{- "\n" }}
+ {{- tool | tojson }}
+ {%- endfor %}
+ {{- "\n" }}
+ {{- '\n\nIf you choose to call a function ONLY reply in the following format with NO suffix:\n\n\n\n\nvalue_1\n\n\nThis is the value for the second parameter\nthat can span\nmultiple lines\n\n\n\n\n\nReminder:\n- Function calls MUST follow the specified format: an inner block must be nested within XML tags\n- Required parameters MUST be specified\n- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n' }}
+ {%- if messages[0].role == 'system' %}
+ {%- set content = render_content(messages[0].content, false, true)|trim %}
+ {%- if content %}
+ {{- '\n\n' + content }}
+ {%- endif %}
+ {%- endif %}
+ {{- '<|im_end|>\n' }}
+{%- else %}
+ {%- if messages[0].role == 'system' %}
+ {%- set content = render_content(messages[0].content, false, true)|trim %}
+ {{- '<|im_start|>system\n' + content + '<|im_end|>\n' }}
+ {%- endif %}
+{%- endif %}
+{%- set ns = namespace(multi_step_tool=true, last_query_index=messages|length - 1) %}
+{%- for message in messages[::-1] %}
+ {%- set index = (messages|length - 1) - loop.index0 %}
+ {%- if ns.multi_step_tool and message.role == "user" %}
+ {%- set content = render_content(message.content, false)|trim %}
+ {%- if not(content.startswith('') and content.endswith('')) %}
+ {%- set ns.multi_step_tool = false %}
+ {%- set ns.last_query_index = index %}
+ {%- endif %}
+ {%- endif %}
+{%- endfor %}
+{%- if ns.multi_step_tool %}
+ {{- raise_exception('No user query found in messages.') }}
+{%- endif %}
+{%- for message in messages %}
+ {%- set content = render_content(message.content, true)|trim %}
+ {%- if message.role == "system" %}
+ {%- if not loop.first %}
+ {{- raise_exception('System message must be at the beginning.') }}
+ {%- endif %}
+ {%- elif message.role == "user" %}
+ {{- '<|im_start|>' + message.role + '\n' + content + '<|im_end|>' + '\n' }}
+ {%- elif message.role == "assistant" %}
+ {%- set reasoning_content = '' %}
+ {%- if message.reasoning_content is string %}
+ {%- set reasoning_content = message.reasoning_content %}
+ {%- else %}
+ {%- if '' in content %}
+ {%- set reasoning_content = content.split('')[0].rstrip('\n').split('')[-1].lstrip('\n') %}
+ {%- set content = content.split('')[-1].lstrip('\n') %}
+ {%- endif %}
+ {%- endif %}
+ {%- set reasoning_content = reasoning_content|trim %}
+ {%- if loop.index0 > ns.last_query_index %}
+ {{- '<|im_start|>' + message.role + '\n\n' + reasoning_content + '\n\n\n' + content }}
+ {%- else %}
+ {{- '<|im_start|>' + message.role + '\n' + content }}
+ {%- endif %}
+ {%- if message.tool_calls and message.tool_calls is iterable and message.tool_calls is not mapping %}
+ {%- for tool_call in message.tool_calls %}
+ {%- if tool_call.function is defined %}
+ {%- set tool_call = tool_call.function %}
+ {%- endif %}
+ {%- if loop.first %}
+ {%- if content|trim %}
+ {{- '\n\n\n\n' }}
+ {%- else %}
+ {{- '\n\n' }}
+ {%- endif %}
+ {%- else %}
+ {{- '\n\n\n' }}
+ {%- endif %}
+ {%- if tool_call.arguments is defined %}
+ {%- for args_name, args_value in tool_call.arguments|items %}
+ {{- '\n' }}
+ {%- set args_value = args_value | tojson | safe if args_value is mapping or (args_value is sequence and args_value is not string) else args_value | string %}
+ {{- args_value }}
+ {{- '\n\n' }}
+ {%- endfor %}
+ {%- endif %}
+ {{- '\n' }}
+ {%- endfor %}
+ {%- endif %}
+ {{- '<|im_end|>\n' }}
+ {%- elif message.role == "tool" %}
+ {%- if loop.previtem and loop.previtem.role != "tool" %}
+ {{- '<|im_start|>user' }}
+ {%- endif %}
+ {{- '\n\n' }}
+ {{- content }}
+ {{- '\n' }}
+ {%- if not loop.last and loop.nextitem.role != "tool" %}
+ {{- '<|im_end|>\n' }}
+ {%- elif loop.last %}
+ {{- '<|im_end|>\n' }}
+ {%- endif %}
+ {%- else %}
+ {{- raise_exception('Unexpected message role.') }}
+ {%- endif %}
+{%- endfor %}
+{%- if add_generation_prompt %}
+ {{- '<|im_start|>assistant\n' }}
+ {%- if enable_thinking is defined and enable_thinking is true %}
+ {{- '\n' }}
+ {%- else %}
+ {{- '\n\n\n\n' }}
+ {%- endif %}
+{%- endif %}
\ No newline at end of file
diff --git a/tests/test-chat.cpp b/tests/test-chat.cpp
index 58fef8e99c7..5067f28808d 100644
--- a/tests/test-chat.cpp
+++ b/tests/test-chat.cpp
@@ -806,6 +806,7 @@ struct peg_test_case {
std::string input;
common_chat_msg expect;
bool is_partial = false;
+ bool expect_partial_rollback = false;
};
struct make_peg_parser {
@@ -889,41 +890,45 @@ static void test_peg_parser(common_chat_templates * tmpls,
std::string prefix = tc.input.substr(0, safe_len);
common_chat_msg msg_current = parser.parse(prefix, is_partial);
- for (const auto & diff : common_chat_msg_diff::compute_diffs(msg_prev, msg_current)) {
- if (!diff.reasoning_content_delta.empty()) {
- msg_accum.reasoning_content += diff.reasoning_content_delta;
- }
- if (!diff.content_delta.empty()) {
- msg_accum.content += diff.content_delta;
- }
- if (diff.tool_call_index != std::string::npos) {
- // During partial parsing, a new tool call may appear with empty name initially
- // The name gets filled in as more input is parsed
- while (msg_accum.tool_calls.size() <= diff.tool_call_index) {
- msg_accum.tool_calls.push_back({ "", "", "" });
- }
- // Always update name and id from diff (may change during incremental parsing), but only if the delta
- // actually contains them
- if (!diff.tool_call_delta.name.empty()) {
- msg_accum.tool_calls[diff.tool_call_index].name = diff.tool_call_delta.name;
+ try {
+ for (const auto & diff : common_chat_msg_diff::compute_diffs(msg_prev, msg_current)) {
+ if (!diff.reasoning_content_delta.empty()) {
+ msg_accum.reasoning_content += diff.reasoning_content_delta;
}
- if (!diff.tool_call_delta.id.empty()) {
- msg_accum.tool_calls[diff.tool_call_index].id = diff.tool_call_delta.id;
+ if (!diff.content_delta.empty()) {
+ msg_accum.content += diff.content_delta;
}
- if (!diff.tool_call_delta.arguments.empty()) {
- msg_accum.tool_calls[diff.tool_call_index].arguments += diff.tool_call_delta.arguments;
+ if (diff.tool_call_index != std::string::npos) {
+ while (msg_accum.tool_calls.size() <= diff.tool_call_index) {
+ msg_accum.tool_calls.push_back({ "", "", "" });
+ }
+ if (!diff.tool_call_delta.name.empty()) {
+ msg_accum.tool_calls[diff.tool_call_index].name = diff.tool_call_delta.name;
+ }
+ if (!diff.tool_call_delta.id.empty()) {
+ msg_accum.tool_calls[diff.tool_call_index].id = diff.tool_call_delta.id;
+ }
+ if (!diff.tool_call_delta.arguments.empty()) {
+ msg_accum.tool_calls[diff.tool_call_index].arguments += diff.tool_call_delta.arguments;
+ }
}
}
- }
- try {
assert_msg_equals(msg_current, msg_accum, true);
} catch (std::exception & e) {
- throw std::runtime_error((std::string("Error comparing accumulated message to current: ") + e.what()).c_str());
+ if (tc.expect_partial_rollback) {
+ return;
+ }
+ throw std::runtime_error((std::string("Error in incremental parse: ") + e.what()).c_str());
}
msg_prev = msg_current;
}
+ if (tc.expect_partial_rollback) {
+ throw std::runtime_error("Partial rollback was expected but did not occur. "
+ "If grammar coverage improved, update this test to expect the extracted content instead.");
+ }
+
if (!tc.is_partial) {
assert_msg_equals(tc.expect, parser.parse(tc.input, false), true);
}
@@ -1098,6 +1103,10 @@ class peg_test_builder {
tc_.is_partial = val;
return *this;
}
+ peg_test_builder & expect_partial_rollback(bool val = true) {
+ tc_.expect_partial_rollback = val;
+ return *this;
+ }
// Expect setters
peg_test_builder & expect(const common_chat_msg & msg) {
@@ -1807,6 +1816,78 @@ static void test_template_output_peg_parsers(bool detailed_debug) {
})
.run();
}
+
+ // Qwen3.5-0.8B: template + basic tool calling + malformed JSON regression
+ {
+ auto tst = peg_tester("models/templates/Qwen-Qwen3.5-0.8B.jinja", /*detailed_debug=*/false);
+
+ static common_chat_tool flashcards_tool{
+ "flashcards", "Flashcards for studying",
+ R"({"type":"object","properties":{"flashcards":{"type":"array","items":{"type":"object","properties":{"query":{"type":"string"},"recall":{"type":"string"}},"required":["recall","query"]}}},"required":["flashcards"]})",
+ };
+
+ tst.test("Hello, world!\nWhat's up?")
+ .enable_thinking(true)
+ .reasoning_format(COMMON_REASONING_FORMAT_DEEPSEEK)
+ .expect(message_assist)
+ .run();
+
+ tst.test(
+ ""
+ "\n"
+ "\n"
+ "\n"
+ "1\n"
+ "\n"
+ "\n"
+ "")
+ .enable_thinking(true)
+ .reasoning_format(COMMON_REASONING_FORMAT_DEEPSEEK)
+ .tools({ special_function_tool })
+ .expect(message_assist_call)
+ .run();
+
+ tst.test(
+ "The user wants flashcards about California.\n"
+ "\n"
+ "\n"
+ "\n"
+ "\n"
+ "\n"
+ "1\n"
+ "\n"
+ "\n"
+ "")
+ .tools({ special_function_tool })
+ .enable_thinking(true)
+ .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
+ .expect_reasoning("The user wants flashcards about California.\n")
+ .expect_tool_calls({
+ { "special_function", R"({"arg1": 1})", {} },
+ })
+ .run();
+
+ // Well-formed JSON: no regression
+ tst.test(
+ "Making cards.\n"
+ "\n\n"
+ "\n"
+ "\n"
+ "\n"
+ "[{\"query\": \"CA\", \"recall\": \"LA\"}]\n"
+ "\n"
+ "\n"
+ "")
+ .tools({ flashcards_tool })
+ .enable_thinking(true)
+ .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
+ .expect_reasoning("Making cards.\n")
+ .expect_tool_calls({
+ { "flashcards", R"({"flashcards": [{"query": "CA", "recall": "LA"}]})", {} },
+ })
+ .run();
+ }
+
{
auto tst = peg_tester("models/templates/deepseek-ai-DeepSeek-V3.1.jinja", detailed_debug);
tst.test(
@@ -1954,6 +2035,39 @@ static void test_template_output_peg_parsers(bool detailed_debug) {
}
}
+ // Qwen3.5 TAG_WITH_TAGGED: trailing newline after .
+ //
+ // This is not canonical inference output. It was observed during inference, but
+ // grammar constraints and/or parallel_tool_calls settings now prevent the model
+ // from generating this exact output at runtime. It exists solely as a regression
+ // test: the trailing \n causes result.fail() with result.end > 0 on the full
+ // parse. On unpatched code this throws std::runtime_error and discards all parsed
+ // content. With the fix, reasoning and tool calls are recovered.
+ {
+ auto tst = peg_tester("models/templates/Qwen-Qwen3.5-0.8B.jinja", /*detailed_debug=*/false);
+
+ static common_chat_tool flashcards_tool{
+ "flashcards", "Flashcards for studying",
+ R"({"type":"object","properties":{"flashcards":{"type":"array","items":{"type":"object","properties":{"query":{"type":"string"},"recall":{"type":"string"}},"required":["recall","query"]}}},"required":["flashcards"]})",
+ };
+
+ tst.test(
+ "Making cards.\n"
+ "\n\n"
+ "\n"
+ "\n"
+ "\n"
+ "[{\"query\": \"CA\", \"recall\": \"LA\"}]\n"
+ "\n"
+ "\n"
+ "\n")
+ .tools({ flashcards_tool })
+ .enable_thinking(true)
+ .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
+ .expect_partial_rollback()
+ .run();
+ }
+
// Kimi-K2-Thinking tests - custom parser
// Unique feature: tool call ID embeds function name as functions.:
{