adding ai_economist for modding

ai_economist/foundation/base/registrar.py

@@ -0,0 +1,103 @@
+# Copyright (c) 2020, salesforce.com, inc.
+# All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+# For full license text, see the LICENSE file in the repo root
+# or https://opensource.org/licenses/BSD-3-Clause
+
+
+class Registry:
+    """Utility for registering sets of similar classes and looking them up by name.
+
+    Registries provide a simple API for getting classes used to build environment
+    instances. Their main purpose is to organize such "building block" classes (i.e.
+    Components, Scenarios, Agents) for easy reference as well as to ensure that all
+    classes within a particular registry inherit from the same Base Class.
+
+    Args:
+        base_class (class): The class that all entries in the registry must be a
+            subclass of.
+
+    Example:
+        class BaseClass:
+            pass
+
+        registry = Registry(BaseClass)
+
+        @registry.add
+        class ExampleSubclassA(BaseClass):
+            name = "ExampleA"
+            pass
+
+        @registry.add
+        class ExampleSubclassB(BaseClass):
+            name = "ExampleB"
+            pass
+
+        print(registry.entries)
+        # ["ExampleA", "ExampleB"]
+
+        assert registry.has("ExampleA")
+        assert registry.get("ExampleB") is ExampleSubclassB
+    """
+
+    def __init__(self, base_class=None):
+        self.base_class = base_class
+        self._entries = []
+        self._lookup = dict()
+
+    def add(self, cls):
+        """Add cls to this registry.
+
+        Args:
+            cls: The class to add to this registry. Must be a subclass of
+                self.base_class.
+
+        Returns:
+            cls (to allow decoration with @registry.add)
+
+        See Registry class docstring for example.
+        """
+        assert "." not in cls.name
+        if self.base_class:
+            assert issubclass(cls, self.base_class)
+        self._lookup[cls.name.lower()] = cls
+        if cls.name not in self._entries:
+            self._entries.append(cls.name)
+        return cls
+
+    def get(self, cls_name):
+        """Return registered class with name cls_name.
+
+        Args:
+            cls_name (str): Name of the registered class to get.
+
+        Returns:
+            Registered class cls, where cls.name matches cls_name (ignoring casing).
+
+        See Registry class docstring for example.
+        """
+        if cls_name.lower() not in self._lookup:
+            raise KeyError('"{}" is not a name of a registered class'.format(cls_name))
+        return self._lookup[cls_name.lower()]
+
+    def has(self, cls_name):
+        """Return True if a class with name cls_name is registered.
+
+        Args:
+            cls_name (str): Name of class to check.
+
+        See Registry class docstring for example.
+        """
+        return cls_name.lower() in self._lookup
+
+    @property
+    def entries(self):
+        """Names of classes in this registry.
+
+        Returns:
+            A list of strings corresponding to the names of classes registered in
+                this registry object.
+
+        See Registry class docstring for example.
+        """
+        return sorted(list(self._entries))