chore: import upstream snapshot with attribution

decoding/GAD/fairseq/tasks/__init__.py

@@ -0,0 +1,128 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+"""isort:skip_file"""
+
+import argparse
+import importlib
+import os
+
+from fairseq.dataclass import FairseqDataclass
+from fairseq.dataclass.utils import merge_with_parent, populate_dataclass
+from hydra.core.config_store import ConfigStore
+
+from .fairseq_task import FairseqTask, LegacyFairseqTask  # noqa
+
+
+# register dataclass
+TASK_DATACLASS_REGISTRY = {}
+TASK_REGISTRY = {}
+TASK_CLASS_NAMES = set()
+
+
+def setup_task(cfg: FairseqDataclass, **kwargs):
+    task = None
+    task_name = getattr(cfg, "task", None)
+
+    if isinstance(task_name, str):
+        # legacy tasks
+        task = TASK_REGISTRY[task_name]
+        if task_name in TASK_DATACLASS_REGISTRY:
+            dc = TASK_DATACLASS_REGISTRY[task_name]
+            cfg = populate_dataclass(dc(), cfg)
+    else:
+        task_name = getattr(cfg, "_name", None)
+
+        if task_name and task_name in TASK_DATACLASS_REGISTRY:
+            dc = TASK_DATACLASS_REGISTRY[task_name]
+            cfg = merge_with_parent(dc(), cfg)
+            task = TASK_REGISTRY[task_name]
+
+    assert task is not None, f"Could not infer task type from {cfg}. Available tasks: {TASK_REGISTRY.keys()}"
+
+    return task.setup_task(cfg, **kwargs)
+
+
+def register_task(name, dataclass=None):
+    """
+    New tasks can be added to fairseq with the
+    :func:`~fairseq.tasks.register_task` function decorator.
+
+    For example::
+
+        @register_task('classification')
+        class ClassificationTask(FairseqTask):
+            (...)
+
+    .. note::
+
+        All Tasks must implement the :class:`~fairseq.tasks.FairseqTask`
+        interface.
+
+    Args:
+        name (str): the name of the task
+    """
+
+    def register_task_cls(cls):
+        if name in TASK_REGISTRY:
+            raise ValueError("Cannot register duplicate task ({})".format(name))
+        if not issubclass(cls, FairseqTask):
+            raise ValueError(
+                "Task ({}: {}) must extend FairseqTask".format(name, cls.__name__)
+            )
+        if cls.__name__ in TASK_CLASS_NAMES:
+            raise ValueError(
+                "Cannot register task with duplicate class name ({})".format(
+                    cls.__name__
+                )
+            )
+        TASK_REGISTRY[name] = cls
+        TASK_CLASS_NAMES.add(cls.__name__)
+
+        if dataclass is not None and not issubclass(dataclass, FairseqDataclass):
+            raise ValueError(
+                "Dataclass {} must extend FairseqDataclass".format(dataclass)
+            )
+
+        cls.__dataclass = dataclass
+        if dataclass is not None:
+            TASK_DATACLASS_REGISTRY[name] = dataclass
+
+            cs = ConfigStore.instance()
+            node = dataclass()
+            node._name = name
+            cs.store(name=name, group="task", node=node, provider="fairseq")
+
+        return cls
+
+    return register_task_cls
+
+
+def get_task(name):
+    return TASK_REGISTRY[name]
+
+
+# automatically import any Python files in the tasks/ directory
+tasks_dir = os.path.dirname(__file__)
+for file in os.listdir(tasks_dir):
+    path = os.path.join(tasks_dir, file)
+    if (
+        not file.startswith("_")
+        and not file.startswith(".")
+        and (file.endswith(".py") or os.path.isdir(path))
+    ):
+        task_name = file[: file.find(".py")] if file.endswith(".py") else file
+        module = importlib.import_module("fairseq.tasks." + task_name)
+
+        # expose `task_parser` for sphinx
+        if task_name in TASK_REGISTRY:
+            parser = argparse.ArgumentParser(add_help=False)
+            group_task = parser.add_argument_group("Task name")
+            # fmt: off
+            group_task.add_argument('--task', metavar=task_name,
+                                    help='Enable this task with: ``--task=' + task_name + '``')
+            # fmt: on
+            group_args = parser.add_argument_group("Additional command-line arguments")
+            TASK_REGISTRY[task_name].add_args(group_args)
+            globals()[task_name + "_parser"] = parser