On 23 Aug, 04:38, c...@tiac.net (Richard Harter) wrote: > On Sat, 22 Aug 2009 14:54:41 -0700 (PDT), James Harris > > > > > > <james.harri...@googlemail.com> wrote: > >On 22 Aug, 10:27, David <71da...@libero.it> wrote: > > >... (snipped a discussion on languages and other systems interpreting > >numbers with a leading zero as octal) > > >> > Either hexadecimal should have been 0h or octal should > >> > have been 0t :=3D) > > >> I have seen the use of Q/q instead in order to make it clearer. I still > >> prefer Smalltalk's 16rFF and 8r377. > > >> Two interesting options. In a project I have on I have also considered > >> using 0q as indicating octal. I maybe saw it used once somewhere else > >> but I have no idea where. 0t was a second choice and 0c third choice > >> (the other letters of oct). 0o should NOT be used for obvious reasons. > > >> So you are saying that Smalltalk has <base in decimal>r<number> where > >> r is presumably for radix? That's maybe best of all. It preserves the > >> syntactic requirement of starting a number with a digit and seems to > >> have greatest flexibility. Not sure how good it looks but it's > >> certainly not bad. > > I opine that a letter is better; special characters are a > valuable piece of real estate.
Very very true. > However for floating point you > need at least three letters because a floating point number has > three parts: the fixed point point, the exponent base, and the > exponent. Now we can represent the radices of the individual > parts with the 'r'scheme, e.g., 2r101001, but we need separate > letters to designate the exponent base and the exponent. B and E > are the obvious choices, though we want to be careful about a > confusion with 'b' in hex. For example, using 'R', > > 3R20.1B2E16Rac Ooh err! > is 20.1 in trinary (6 1/3) times 2**172 (hex ac). > > I grant that this example looks a bit gobbledegookish, You think? :-) > but normal > usage would be much simpler. The notation doesn't handle > balanced trinary; however I opine that balanced trinary requires > special notation. When the programmer needs to construct such values how about allowing him or her to specify something like (20.1 in base 3) times 2 to the power of 0xac Leaving out how to specify (20.1 in base 3) for now this could be (20.1 in base 3) * 2 ** 0xac The compiler could convert this to a constant. James -- http://mail.python.org/mailman/listinfo/python-list
