On Jun 28, 2007, at 5:04 PM, Martin Albrecht wrote:
> Hi there, > > I often come across the situation where I have to construct an > integer from > its binary representation and vice versa. So far you do it in SAGE > using > strings. I have attached a preliminary patch which allows the > following code > to work, i.e. I _replaced_ the binary() method (which returned a > string) with > a method that returns a tuple of Python ints. > > sage: e = ZZ(10231252).binary(); e > (1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, > 0, 0) > sage: ZZ(e,2) > 10231252 > > I know that this patch has some issues: > * it breaks doctests which rely on strings (fix by replace ZZ.binary > () with > ZZ.str(2)) > * it returns a tuple of Python ints should return tuple (?) of GF > (2) elements > but I didn't want to mess with imports yet > * it can be done faster > * you loose the minus sign: ZZ(-1).binary() is (1,), shall it raise an > exception then? > > I am not out for micromanagement but I hesitate to just submit a > polished > patch as the Integers are such a central building block of SAGE. > So, does > anybody actually like the current behavior of ZZ.binary() which > returns a > (signed) string? Any other objections against making the above work? Hmmm I don't know if I like this. Well, I don't have any objections to such a method being available, but I prefer the name "binary" to have the current behaviour. It's more pythonic, like the hex function. BTW for the list format, I would prefer the least significant bit to be listed first. This is more like the list() function for polynomials, if you think of an integer as a polynomial in 2: eleven = 1*2^0 + 1*2^1 + 0*2^2 + 1*2^3 = [1, 1, 0, 1] david --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
