Add option to disable any_whitespace for xgrammar and llguidance backends. (#8919)

Co-authored-by: Chang Su <chang.s.su@oracle.com>

python/sglang/srt/constrained/xgrammar_backend.py

@@ -167,6 +167,7 @@ class XGrammarGrammarBackend(BaseGrammarBackend):
         tokenizer,
         vocab_size: int,
         model_eos_token_ids: Optional[List[int]] = None,
+        any_whitespace: bool = True,
     ):
         super().__init__()
 
@@ -188,6 +189,7 @@ class XGrammarGrammarBackend(BaseGrammarBackend):
         self.grammar_compiler = GrammarCompiler(tokenizer_info=tokenizer_info)
         self.vocab_size = vocab_size
         self.override_stop_tokens = override_stop_tokens
+        self.any_whitespace = any_whitespace
 
     def _from_context(
         self, ctx: CompiledGrammar, key_string: str, grammar_stats: GrammarStats
@@ -212,7 +214,9 @@ class XGrammarGrammarBackend(BaseGrammarBackend):
                 # Note: This builtin JSON grammar includes *all* valid JSON (including, for example, arrays at the root)
                 ctx = self.grammar_compiler.compile_builtin_json_grammar()
             else:
-                ctx = self.grammar_compiler.compile_json_schema(schema=key_string)
+                ctx = self.grammar_compiler.compile_json_schema(
+                    schema=key_string, any_whitespace=self.any_whitespace
+                )
 
         except (RuntimeError, json.decoder.JSONDecodeError) as e:
             logging.error(f"Hit invalid json_schema: {key_string=}, {e=}")