Move sgl.Runtime under sglang/lang (#2990)

python/sglang/srt/constrained/__init__.py

@@ -1,16 +0,0 @@
-# Copyright 2023-2024 SGLang Team
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ==============================================================================
-
-# TODO(lmzheng): make this an optional dependency
-from sglang.srt.constrained.outlines_backend import build_regex_from_object

python/sglang/srt/constrained/base_grammar_backend.py

@@ -18,6 +18,8 @@ from dataclasses import dataclass
 from threading import Event, Lock
 from typing import Any, Optional, Tuple
 
+from sglang.srt.server_args import ServerArgs
+
 
 @dataclass
 class CacheEntry:
@@ -69,3 +71,22 @@ class BaseGrammarBackend:
     def reset(self):
         with self.cache_lock:
             self.cache.clear()
+
+
+def create_grammar_backend(server_args: ServerArgs, tokenizer, vocab_size):
+    if server_args.grammar_backend == "outlines":
+        from sglang.srt.constrained.outlines_backend import OutlinesGrammarBackend
+
+        grammar_backend = OutlinesGrammarBackend(
+            tokenizer,
+            whitespace_pattern=server_args.constrained_json_whitespace_pattern,
+            allow_jump_forward=not server_args.disable_jump_forward,
+        )
+    elif server_args.grammar_backend == "xgrammar":
+        from sglang.srt.constrained.xgrammar_backend import XGrammarGrammarBackend
+
+        grammar_backend = XGrammarGrammarBackend(tokenizer, vocab_size=vocab_size)
+    else:
+        raise ValueError(f"Invalid grammar backend: {server_args.grammar_backend}")
+
+    return grammar_backend