flat_dict_to_nested

src/clippy/backends/expression.py

@@ -9,6 +9,8 @@
 import json
 from .serialization import ClippySerializable
 from ..anydict import AnyDict
+from ..utils import flat_dict_to_nested
+
 
 from typing import Any
 
@@ -184,12 +186,19 @@ def _clear_subselectors(self):
             delattr(self, subsel)
         self.subselectors = set()
 
-    def _import_from_dict(self, d: AnyDict, merge: bool = False):
+    def _import_from_dict(self, flat_dict: AnyDict, merge: bool = False):
         '''Imports subselectors from a dictionary.
-        If `merge = True`, do not clear subselectors first.'''
+        If `merge = True`, do not clear subselectors first.
+
+        Input dictionary has dot-delimited keys. This function uses
+        utils.flat_dict_to_nested to create the nested dictionary.
+        '''
+
+        d = flat_dict_to_nested(flat_dict)
         # clear all children
         if not merge:
             self._clear_subselectors()
+
         for name, subdict in d.items():
             docstr = subdict.get('__doc__', '')
             self._add_subselector(name, docstr)

src/clippy/utils.py

@@ -0,0 +1,26 @@
+"""
+    Utility functions
+"""
+
+from .anydict import AnyDict
+from .error import ClippyInvalidSelectorError
+
+
+def flat_dict_to_nested(input_dict: AnyDict) -> AnyDict:
+    """input dictionary has dot-delineated keys which are then parsed as subkeys.
+    That is: {'a.b.c': 5} becomes {'a': {'b': {'c': 5}}}
+    """
+
+    output_dict: AnyDict = {}
+    for k, v in input_dict.items():
+        # k is dotted
+        if '.' not in k:
+            raise ClippyInvalidSelectorError("cannot set top-level selectors")
+
+        *path, last = k.split('.')
+        curr_nest = output_dict
+        for p in path:
+            curr_nest = output_dict.setdefault(p, {})
+
+        curr_nest[last] = v
+    return output_dict