up follow livre

venv/lib/python3.13/site-packages/fontTools/misc/dictTools.py

@@ -0,0 +1,83 @@
+"""Misc dict tools."""
+
+__all__ = ["hashdict"]
+
+
+# https://stackoverflow.com/questions/1151658/python-hashable-dicts
+class hashdict(dict):
+    """
+    hashable dict implementation, suitable for use as a key into
+    other dicts.
+
+        >>> h1 = hashdict({"apples": 1, "bananas":2})
+        >>> h2 = hashdict({"bananas": 3, "mangoes": 5})
+        >>> h1+h2
+        hashdict(apples=1, bananas=3, mangoes=5)
+        >>> d1 = {}
+        >>> d1[h1] = "salad"
+        >>> d1[h1]
+        'salad'
+        >>> d1[h2]
+        Traceback (most recent call last):
+        ...
+        KeyError: hashdict(bananas=3, mangoes=5)
+
+    based on answers from
+       http://stackoverflow.com/questions/1151658/python-hashable-dicts
+
+    """
+
+    def __key(self):
+        return tuple(sorted(self.items()))
+
+    def __repr__(self):
+        return "{0}({1})".format(
+            self.__class__.__name__,
+            ", ".join("{0}={1}".format(str(i[0]), repr(i[1])) for i in self.__key()),
+        )
+
+    def __hash__(self):
+        return hash(self.__key())
+
+    def __setitem__(self, key, value):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def __delitem__(self, key):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def clear(self):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def pop(self, *args, **kwargs):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def popitem(self, *args, **kwargs):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def setdefault(self, *args, **kwargs):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    def update(self, *args, **kwargs):
+        raise TypeError(
+            "{0} does not support item assignment".format(self.__class__.__name__)
+        )
+
+    # update is not ok because it mutates the object
+    # __add__ is ok because it creates a new object
+    # while the new object is under construction, it's ok to mutate it
+    def __add__(self, right):
+        result = hashdict(self)
+        dict.update(result, right)
+        return result