[Python-checkins] r60706 - peps/trunk/pep-3141.txt

[guido.van.rossum]

Author: guido.van.rossum
Date: Sun Feb 10 02:14:46 2008
New Revision: 60706

Modified:
   peps/trunk/pep-3141.txt
Log:
Explicitly acknowledge that Decimal will not become part of the numeric tower.


Modified: peps/trunk/pep-3141.txt
==============================================================================
--- peps/trunk/pep-3141.txt	(original)
+++ peps/trunk/pep-3141.txt	Sun Feb 10 02:14:46 2008
@@ -171,7 +171,7 @@
         """
 
         # XXX What to do about the __int__ implementation that's
-        # currently present on float and Decimal?  Get rid of it?
+        # currently present on float?  Get rid of it?
 
         @abstractmethod
         def __float__(self):
@@ -208,8 +208,7 @@
             If ndigits is omitted or None, returns an Integral,
             otherwise returns a Real, preferably of the same type as
             self. Types may choose which direction to round half. For
-            example, float rounds half toward even, and Decimal rounds
-            it according to the current context.
+            example, float rounds half toward even.
 
             """
             raise NotImplementedError
@@ -319,7 +318,7 @@
             raise NotImplementedError
 
         def __index__(self):
-            """__index__() exists because float and Decimal have __int__()."""
+            """__index__() exists because float has __int__()."""
             return int(self)
 
         @abstractmethod
@@ -440,10 +439,9 @@
 In 2.6, ``math.floor``, ``math.ceil``, and ``round`` will continue to
 return floats.
 
-Because the ``int()`` conversion implemented by ``float`` (and by
-``decimal.Decimal``) is equivalent to but less explicit than
-``trunc()``, let's remove it. (Or, if that breaks too much, just add a
-deprecation warning.)
+The ``int()`` conversion implemented by ``float`` is equivalent to
+``trunc()``.  In general, the ``int()`` conversion should try
+``__int__()`` first and if it is not found, try ``__trunc__()``.
 
 ``complex.__{divmod,mod,floordiv,int,float}__`` also go away. It would
 be nice to provide a nice error message to help confused porters, but
@@ -554,6 +552,14 @@
 more closely.
 
 
+The Decimal Type
+================
+
+After consultation with its authors it has been decided that the
+``Decimal`` type should not at this time be made part of the numeric
+tower.
+
+
 References
 ==========