Tim Peters wrote:
[Tim]
Python's grammar is such that negative integer literals don't exist; what you actually have there is the unary minus operator applied to positive integer literals; ...
[Christian Tismer]
Well, knowing that there are more negatives than positives and then coding it this way appears in fact as a design flaw to me.
Don't know what you're saying here.
On a 2's-complement machine, there are 2**(n-1) negatives, zero, and 2**(n-1)-1 positives. The most negative number cannot be inverted. Most machines today use the 2's complement.
Python's grammar has nothing to do with the relative number of positive vs negative entities; indeed, in a 2's-complement machine it's not even true that there are more negatives than positives.
If I read this 1's-complement machine then I believe it. But we don't need to split hair on known stuff :-)
Python generates the unary minus for "negative literals" because, again, negative literals *don't exist* in the grammar.
Yes. If I know the facts and don't build negative literals into the grammar, then I call it an oversight. Not too bad but not nice.
A simple solution could be to do the opposite: Always store a negative number and negate it for positive numbers. ...
So long as negative literals don't exist in the grammar, "-2147483648" makes no sense on a 2's-complement machine with 32-bit C longs. There isn't "a problem" here worth fixing, although if there is <wink>, it will get fixed by magic as soon as Python ints and longs are unified.
I'd change the grammar. ciao - chris -- Christian Tismer :^) <mailto:tismer@appliedbiometrics.com> Applied Biometrics GmbH : Have a break! Take a ride on Python's Kaunstr. 26 : *Starship* http://starship.python.net 14163 Berlin : PGP key -> http://wwwkeys.pgp.net PGP Fingerprint E182 71C7 1A9D 66E9 9D15 D3CC D4D7 93E2 1FAE F6DF where do you want to jump today? http://www.stackless.com