enh: make env and dyn provide the Mapping API

Author: Technologicat

unpythonic/collections.py

@@ -17,6 +17,8 @@
 
 from .llist import cons
 from .misc import getattrrec
+from .env import env
+from .dynassign import _Env
 
 def get_abcs(cls):
     """Return a set of the collections.abc superclasses of cls (virtuals too)."""
@@ -100,7 +102,9 @@ def doit(x):
         # immutable containers
         elif isinstance(x, cons):
             return cons(doit(x.car), doit(x.cdr))
-        elif isinstance(x, Mapping):
+        # env and dyn provide the Mapping API, but shouldn't get the general Mapping treatment here.
+        # (This is important for the curry and lazify macros.)
+        elif isinstance(x, Mapping) and not isinstance(x, (env, _Env)):
             ctor = type(x)
             return ctor({k: doit(v) for k, v in x.items()})
         elif isinstance(x, Sequence) and not isinstance(x, (str, bytes, range)):

unpythonic/dynassign.py

@@ -5,6 +5,7 @@
 
 import threading
 from collections import ChainMap
+from collections.abc import Container, Sized, Iterable, Mapping
 
 # Each new thread, when spawned, inherits the contents of the main thread's
 # dynamic scope stack.
@@ -148,14 +149,23 @@ def asdict(self):
         """
         return _DynLiveView()
 
-    def items(self):
-        """Abbreviation for asdict().items()."""
-        return self.asdict().items()
-
     def __iter__(self):
         return iter(self.asdict())
     # no __next__, iterating over dict.
 
+    # Mapping
+    def items(self):
+        """Abbreviation for asdict().items()."""
+        return self.asdict().items()
+    def keys(self):
+        return self.asdict().keys()
+    def values(self):
+        return self.asdict().values()
+    def get(self, k, default=None):
+        return self[k] if k in self else default
+    def __eq__(self, other):  # dyn is a singleton, but its contents can be compared to another mapping.
+        return other == self.asdict()
+
     def __len__(self):
         return len(self.asdict())
 
@@ -199,3 +209,8 @@ def make_dynvar(**bindings):
         _global_dynvars[name] = bindings[name]
 
 dyn = _Env()
+
+# register virtual base classes
+for abscls in (Container, Sized, Iterable, Mapping):
+    abscls.register(_Env)
+del abscls

unpythonic/env.py

@@ -3,6 +3,8 @@
 
 __all__ = ["env"]
 
+from collections.abc import Container, Sized, Iterable, Mapping
+
 class env:
     """Environment for let-like constructs.
 
@@ -90,9 +92,18 @@ def __iter__(self):
         return self._env.__iter__()
     # no __next__, iterating over dict.
 
+    # Mapping
     def items(self):
         """Like dict.items()."""
         return self._env.items()
+    def keys(self):
+        return self._env.keys()
+    def values(self):
+        return self._env.values()
+    def get(self, k, default=None):
+        return self[k] if k in self else default
+    def __eq__(self, other):
+        return other == self._env
 
     def __len__(self):
         return len(self._env)
@@ -193,3 +204,8 @@ def finalize(self):
 #                    return cls(obj)  # copy-construct obj without wrapper
 #            assert False, "wrapped value missing in {} {}".format(type(obj), obj)
 #        return _assignonce_wrapper(obj)  # copy-construct obj with wrapper
+
+# register virtual base classes
+for abscls in (Container, Sized, Iterable, Mapping):
+    abscls.register(env)
+del abscls

unpythonic/llist.py

@@ -5,6 +5,7 @@
 """
 
 from abc import ABCMeta, abstractmethod
+from collections.abc import Iterable, Iterator
 from itertools import zip_longest
 
 from .fun import composer1i
@@ -71,6 +72,8 @@ def __iter__(self):
         return self
     def __next__(self):
         return next(self.walker)
+Iterable.register(ConsIterator)
+Iterator.register(ConsIterator)
 
 class LinkedListIterator(ConsIterator):
     """Iterator for linked lists built from cons cells."""