Re: Ternary operator patch
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Ternary operator patch
- From: Tony Finch <dot@...>
- Date: 2010年9月16日 16:37:57 +0100
On 2010年9月16日, David Given wrote:
>
> But what's the issue with & and |? & has a higher priority than |, which
> is what I'd expect (boolean multiply vs boolean add).
The problem is their precedence relative to the comparison operators.
if (a & 15 == 0) fail();
In a better world C's precedence table would be:
() [] -> . ++ -- left to right
- ! ~ ++ -- * & (type) sizeof right to left
* / % & << >> left to right
+ - ^ | left to right
< <= > >= == != left to right
&& left to right
|| left to right
?: right to left
= += -= *= /= %= <<= >>= &= ^= |= right to left
, left to right
Even better would be to replace prefix * with postfix ^ (like Pascal)
which would fix the tortured declaration syntax. Postfix ^ can be optional
before . just like it is before () and [], so you can abolish ->. Infix ^
would need to be spelled differently to avoid a clash; ~ would make sense
by analogy with -. It should also be possible to chain comparison
operators like BCPL and Python. Then you would get:
() [] ^ . ++ -- left to right
- ! ~ ++ -- & (type) sizeof right to left
* / % & << >> left to right
+ - ~ | left to right
< <= > >= == != chained
&& left to right
|| left to right
?: right to left
= += -= *= /= %= <<= >>= &= ^= |= right to left
, left to right
Tony.
--
f.anthony.n.finch <dot@dotat.at> http://dotat.at/
HUMBER THAMES DOVER WIGHT PORTLAND: NORTH BACKING WEST OR NORTHWEST, 5 TO 7,
DECREASING 4 OR 5, OCCASIONALLY 6 LATER IN HUMBER AND THAMES. MODERATE OR
ROUGH. RAIN THEN FAIR. GOOD.
- References:
- Re: Ternary operator patch, Doug Rogers
- Re: Ternary operator patch, Ryota Hirose
- Re: Ternary operator patch, Ryota Hirose
- Re: Ternary operator patch, David Kastrup
- Re: Ternary operator patch, Miles Bader
- Re: Ternary operator patch, David Kastrup
- Re: Ternary operator patch, Ryota Hirose
- Re: Ternary operator patch, David Kastrup
- Re: Ternary operator patch, Ryota Hirose
- Re: Ternary operator patch, David Kastrup
- Re: Ternary operator patch, Roberto Ierusalimschy
- Re: Ternary operator patch, David Given