+1 for all of your opinions. I also believe that wrong assumption on
precedence is a reason of big number of errors. More, I believe precedence
in complex expressions can confuse not less than removed ++/-- operators
(or requirement to explicit type conversions for different integers types
in expression) and it will be Swifty way to prevent this kind of confusion
also in the language.
On 15.06.2016 11:31, Haravikk via swift-evolution wrote:
On 15 Jun 2016, at 00:21, Xiaodi Wu via swift-evolution
<swift-evolution@swift.org> wrote: I don't know that it's feasible to
warn on every use of operators with mixed precedence. Doing so would
effectively do away with the concept of precedence at all, since
everything would have to be grouped by parentheses in order to avoid
warnings. (The core team has been pretty clear that there will be no
'optional' warnings, and in certain organizations warnings are
regarded as errors.)
Personally I’m against precedence entirely, as I’m terrible at
remembering the order and even if I could I’d still see myself making
tons of mistakes, as a result I use parenthesis in all but the simplest
statements just to be absolutely clear. The problem with precedence is
that while it lets the compiler choose a logical order to process
expressions, you can never be sure that it’s actually the order the user
intended.
Still, I may be in the minority, not sure, maybe other people are
happier with math operator precedence than I am. However, I think that
effectively forcing parenthesis on ?? and ?: may be okay; most of the
time these are used in simple, non-ambiguous cases (either on their own,
or with an assignment), so parenthesis shouldn’t be needed, but anywhere
they’re within larger statements I think it makes sense to encourage
parenthesis use so the compiler can be certain it isn’t guessing at your
meaning. I mean it’s kind of like forcing a defensive coding style, but
that’s not necessarily a bad thing; I’ve learned from experience that I
suck at operator precedence and instead of wasting time looking it up to
be sure, hurling a bunch of parenthesis in place not only clarifies my
intent, but avoids the problem entirely, I wish more people would do it,
as I still run into cases in other people’s code where it takes some
time to figure out meaning (usually because these operator precedence
obsessed monsters don’t leave comments either ;)
Increasing the precedence won’t help IMO, as it remains just as possible
for a user to make a mistake, plus we run the risk of changing the
result of currently correct code that works fine with the current
precedence but will suddenly give different results if evaluated
sooner.
So yeah, I think recommending parenthesis is a good compromise, and good
style to encourage when using these operators in more complex cases, not
just for avoiding mistakes but also to make the code more readable for
others. _______________________________________________ swift-evolution
mailing list swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution
_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution
