Add back spacy.TransitionBasedParser.v2

spacy/errors.py

@@ -213,6 +213,8 @@ class Warnings(metaclass=ErrorsWithCodes):
     W122 = ("Couldn't trace method '{method}' in pipe '{pipe}'. This can happen if the pipe class "
             "is a Cython extension type.")
 
+    W400 = ("`use_upper=False` is ignored, the upper layer is always enabled")
+
 
 class Errors(metaclass=ErrorsWithCodes):
     E001 = ("No component '{name}' found in pipeline. Available names: {opts}")

spacy/ml/models/parser.py

@@ -1,8 +1,9 @@
 from typing import Optional, List, Tuple, Any
 from thinc.types import Floats2d
 from thinc.api import Model
+import warnings
 
-from ...errors import Errors
+from ...errors import Errors, Warnings
 from ...compat import Literal
 from ...util import registry
 from ..tb_framework import TransitionModel
@@ -12,6 +13,29 @@ TransitionSystem = Any  # TODO
 State = Any  # TODO
 
 
+@registry.architectures.register("spacy.TransitionBasedParser.v2")
+def transition_parser_v2(
+    tok2vec: Model[List[Doc], List[Floats2d]],
+    state_type: Literal["parser", "ner"],
+    extra_state_tokens: bool,
+    hidden_width: int,
+    maxout_pieces: int,
+    use_upper: bool,
+    nO: Optional[int] = None,
+) -> Model:
+    if not use_upper:
+        warnings.warn(Warnings.W400)
+
+    return build_tb_parser_model(
+        tok2vec,
+        state_type,
+        extra_state_tokens,
+        hidden_width,
+        maxout_pieces,
+        nO=nO,
+    )
+
+
 @registry.architectures.register("spacy.TransitionBasedParser.v3")
 def transition_parser_v3(
     tok2vec: Model[List[Doc], List[Floats2d]],

spacy/tests/parser/test_parse.py

@@ -459,6 +459,8 @@ def test_overfitting_IO(pipe_name):
 @pytest.mark.parametrize(
     "parser_config",
     [
+        ({"@architectures": "spacy.TransitionBasedParser.v2", "tok2vec": DEFAULT_TOK2VEC_MODEL, "state_type": "parser", "extra_state_tokens": False, "hidden_width": 64, "maxout_pieces": 2, "use_upper": True}),
+        ({"@architectures": "spacy.TransitionBasedParser.v2", "tok2vec": DEFAULT_TOK2VEC_MODEL, "state_type": "parser", "extra_state_tokens": False, "hidden_width": 64, "maxout_pieces": 2, "use_upper": False}),
         ({"@architectures": "spacy.TransitionBasedParser.v3", "tok2vec": DEFAULT_TOK2VEC_MODEL, "state_type": "parser", "extra_state_tokens": False, "hidden_width": 64, "maxout_pieces": 2}),
     ],
 )