On 4/3/11 2:14 AM, Russel Winder wrote:
On Sat, 2011-04-02 at 18:20 -0500, Andrei Alexandrescu wrote:
On 4/2/11 5:27 PM, ulrik.mikaels...@gmail.com wrote:
A D-newbie would probably be able to guess 0o for octal, but
hardly octal!. octal! breaks the rule of least surprise.
I fail to infer how using the word "octal" for an octal literal is
surprising at all.
The problem is not that it is a poor solution in isolation, it is
the conflict between 0b... and 0x.. versus octal!... Why is octal
being discriminated against compared to binary and hexadecimal?
It's very simple. You are making a number of fallacious assumptions
which logically lead to a wrong conclusion.
First fallacy is:
What is the use for binary literals or hexadecimal literals, I can't
think of one.
Just looking through std/ yields 1849 lines with 0x in them, of which
many have several instances on the same line.
The second fallacy is assigning equal weight to every feature or
potential feature. A language should not be a democracy.
The third fallacy is a unidimensional view of consistency. It's very
easy to first limit the notion of consistency to only one possible
dimension, to then show that a lot of stuff is inconsistent. In reality
there are many dimensions of consistency, and choosing their right
relative importance is much of the difficulty of language design.
Keeping 0x in the language is consistent with the general similarity of
D with C, C++, Java, and many others.
Eliminating 0777 from the language is consistent with the notion that
leading zeros are insignificant in regular decimal notation in math. It
is also consistent with the desire of preventing subtle mistakes made by
people who make the math-based assumption.
Adding octal!777 to std.conv is consistent with the notion that there
still are a few uses for octal constants that are worth a presence in
the standard library. It is also consistent with the desire to foster
other user-defined literals defined from the same mold.
Andrei
