fix bug: dict_items handling in mogrify (combo with curry macro and frozendict)

Author: Technologicat

unpythonic/collections.py

@@ -27,6 +27,7 @@ def get_abcs(cls):
 # TODO: allow multiple input container args in mogrify, like map does (also support longest, fillvalue)
 #   OTOH, that's assuming an ordered iterable... so maybe not for general containers?
 # TODO: move to unpythonic.it? This is a spork...
+_dictitems_type = type({}.items())
 def mogrify(func, container):
     """In-place recursive map for mutable containers.
 
@@ -115,7 +116,8 @@ def doit(x):
             ctor = cls._make if hasattr(cls, "_make") else cls
             return ctor(doit(elt) for elt in x)
         elif isinstance(x, Set):
-            ctor = type(x)
+            # dict_items cannot be instantiated, so return a regular set if we're asked to mogrify one
+            ctor = type(x) if not isinstance(x, _dictitems_type) else set
             return ctor({doit(elt) for elt in x})
         return func(x)  # atom
     return doit(container)

unpythonic/syntax/test/test_curry.py

@@ -6,6 +6,7 @@
 from ...fold import foldr
 from ...fun import composerc as compose
 from ...llist import cons, nil, ll
+from ...collections import frozendict
 
 def test():
     with curry:
@@ -70,6 +71,13 @@ def add3(a, b, c):
                                     acc if n == 0 else jump(self, n - 1, n * acc))))
         assert fact(5) == 120
 
+    # dict_items handling in mogrify
+    with curry:
+        d1 = frozendict(foo='bar', bar='tavern')
+        d2 = frozendict(d1, bar='pub')
+        assert tuple(sorted(d1.items())) == (('bar', 'tavern'), ('foo', 'bar'))
+        assert tuple(sorted(d2.items())) == (('bar', 'pub'), ('foo', 'bar'))
+
     print("All tests PASSED")
 
 if __name__ == '__main__':