[V1][Core] Support for Structured Outputs (#12388)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>
Signed-off-by: Russell Bryant <rbryant@redhat.com>
Co-authored-by: Russell Bryant <rbryant@redhat.com>
Co-authored-by: Michael Goin <mgoin64@gmail.com>
Co-authored-by: Nick Hill <nhill@redhat.com>

tests/v1/entrypoints/conftest.py

@@ -29,6 +29,7 @@ def sample_regex():
             r"(25[0-5]|(2[0-4]|1\d|[1-9]|)\d)")
 
 
+# Note: Ensure this only uses attributes compatible with xgrammar
 @pytest.fixture
 def sample_json_schema():
     return {
@@ -44,9 +45,7 @@ def sample_json_schema():
                 "type": "array",
                 "items": {
                     "type": "string",
-                    "maxLength": 10
-                },
-                "minItems": 3
+                }
             },
             "work_history": {
                 "type": "array",
@@ -71,8 +70,9 @@ def sample_json_schema():
     }
 
 
+# A schema unsupported by xgrammar
 @pytest.fixture
-def sample_complex_json_schema():
+def unsupported_json_schema():
     return {
         "type": "object",
         "properties": {
@@ -150,7 +150,19 @@ def sample_guided_choice():
 
 
 @pytest.fixture
-def sample_sql_statements():
+def sample_sql_ebnf():
+    return """
+root ::= select_statement
+select_statement ::= "SELECT" column "from" table "where" condition
+column ::= "col_1" | "col_2"
+table ::= "table_1" | "table_2"
+condition ::= column "=" number
+number ::= "1" | "2"
+"""
+
+
+@pytest.fixture
+def sample_sql_lark():
     return ("""
 start: select_statement
 select_statement: "SELECT" column "from" table "where" condition