Re: Ternary operator patch

[Tony Finch <dot@...>]

On Thu, 16 Sep 2010, 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.
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