✨ 支持流式回复与按行消息解析

nonebot_plugin_llmchat/output_protocol.py

@@ -0,0 +1,70 @@
+"""把模型的按行回复解析为聊天消息。"""
+
+NO_REPLY = "<<<LLMCHAT_NO_REPLY>>>"
+BLOCK_FENCE = "```"
+
+
+class ReplyLineParser:
+    """增量解析普通文本行，并把 fenced content block 保留为单条消息。"""
+
+    def __init__(self) -> None:
+        self._pending = ""
+        self._in_block = False
+        self._block_lines: list[str] = []
+
+    def feed(self, fragment: str) -> list[str]:
+        self._pending += fragment
+        messages: list[str] = []
+        while boundary := self._next_boundary():
+            index, marker = boundary
+            line = self._pending[:index]
+            self._pending = self._pending[index + len(marker) :]
+            messages.extend(self._consume_line(line))
+
+        # 内容块的结束标记无需等待下一个换行符。
+        if self._in_block and self._pending.strip() == BLOCK_FENCE:
+            self._pending = ""
+            messages.extend(self._consume_line(BLOCK_FENCE))
+        return messages
+
+    def finish(self) -> list[str]:
+        messages: list[str] = []
+        if self._pending:
+            messages.extend(self._consume_line(self._pending))
+            self._pending = ""
+        if self._in_block:
+            messages.extend(self._flush_block())
+        return messages
+
+    def _next_boundary(self) -> tuple[int, str] | None:
+        markers = ("\n",)
+        matches = [(index, marker) for marker in markers if (index := self._pending.find(marker)) >= 0]
+        return min(matches, key=lambda match: match[0]) if matches else None
+
+    def _consume_line(self, line: str) -> list[str]:
+        line = line.removesuffix("\r")
+        stripped = line.strip()
+        if self._in_block:
+            if stripped == BLOCK_FENCE:
+                return self._flush_block()
+            self._block_lines.append(line)
+            return []
+        if stripped.startswith(BLOCK_FENCE):
+            self._in_block = True
+            self._block_lines = []
+            return []
+        if not stripped or stripped == NO_REPLY:
+            return []
+        return [stripped]
+
+    def _flush_block(self) -> list[str]:
+        block = "\n".join(self._block_lines).strip("\n")
+        self._in_block = False
+        self._block_lines = []
+        return [block] if block else []
+
+
+def parse_reply_segments(content: str) -> list[str]:
+    """解析完整回复：普通行拆分，内容框保持为整体。"""
+    parser = ReplyLineParser()
+    return [*parser.feed(content), *parser.finish()]