[Bugfix] remove fallback in guided_json (int range, patterns) (#16725)

Signed-off-by: csy1204 <josang1204@gmail.com>
Co-authored-by: 조상연[플레이스 AI] <sang-yeon.cho@navercorp.com>

vllm/model_executor/guided_decoding/__init__.py

@@ -65,7 +65,7 @@ def maybe_backend_fallback(
             fallback_or_error(
                 guided_params,
                 "xgrammar does not support advanced JSON schema features like "
-                "enums, patterns or numeric ranges.", "outlines")
+                "string length, item limits, or property bounds.", "outlines")
 
         # xgrammar only supports GBNF grammars, so we must convert Lark.
         # We must check if the grammar is likely Lark and if that

vllm/model_executor/guided_decoding/utils.py

@@ -10,16 +10,8 @@ def has_xgrammar_unsupported_json_features(schema: dict) -> bool:
         if not isinstance(obj, dict):
             return False
 
-        # Check for pattern restrictions
-        if "pattern" in obj:
-            return True
-
         # Check for numeric ranges
-        if obj.get("type") in ("integer", "number") and any(
-                key in obj for key in [
-                    "minimum", "maximum", "exclusiveMinimum",
-                    "exclusiveMaximum", "multipleOf"
-                ]):
+        if obj.get("type") in ("integer", "number") and ("multipleOf" in obj):
             return True
 
         # Check for array unsupported keywords