Addenda: j.) The same rules would need to apply to all forms of the Decimal contructor, so Decimal(someint) would also need to truncate/round if it has more than precision digits -- likewise with Decimal(fromtuple) and Decimal(fromdecimal). All are problematic. Integer conversions are expected to be exact but may not be after the change. Conversion from another decimal should be idempotent but implicit rounding/truncation will break that. The fromtuple/totuple round-trip can get broken. You generally specify a tuple when you know exactly what you want.
k.) The biggest client of all these methods is the Decimal module itself. Throughout the implementation, the code calls the Decimal constructor to create intermediate values. Every one of those calls would need to be changed to specify a context. Some of those cases are not trivially changed (for instance, the hash method doesn't have a context but it needs to check to see if a decimal value is exactly an integer so it can hash to that value). Likewise, how do you use a decimal value for a dictionary key when the equality check is context dependent (change precision and lose the ability to reference an entry)? Be careful with this proposed change. It is a can of worms. Better yet, don't do it. We already have a context aware constructor method if that is what you really want. Raymond _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
