[Feature] New structural tag support (#10691)

python/sglang/srt/constrained/utils.py

@@ -0,0 +1,12 @@
+from typing import Dict
+
+
+def is_legacy_structural_tag(obj: Dict) -> bool:
+    # test whether an object is a legacy structural tag
+    # see `StructuralTagResponseFormat` at `sglang.srt.entrypoints.openai.protocol`
+    if obj.get("structures", None) is not None:
+        assert obj.get("triggers", None) is not None
+        return True
+    else:
+        assert obj.get("format", None) is not None
+        return False