[swift-evolution] ternary operator ?: suggestion

[J. Cheyo Jimenez]

Thank you Paul for the initial draft.

Here is the a draft version that I intend to submit.

https://github.com/masters3d/swift-evolution/blob/ReplaceTernary/proposals/00-Replace%20%3F:%20Ternary%20Operator%20with%20if-then-else%20expression.md

On Monday, December 14, 2015, Paul Ossenbruggen via swift-evolution <
swift-evolution at swift.org> wrote:

> Agreed, I was thinking to I really want turn something that was 2
> characters into 10 and will I really be happy with that at the end of the
> day. A properly formatted ternary can be quite easy to read, it is when
> people get sloppy and try to cram too much into one expression that they
> get really hard to follow. For example,
>
>     return (a<b) ? (b<c) ? b : (a<c) ? c : a : (a<c) ? a : (b<c) ? c : b;
>
> If formatted like this becomes easier follow the logic (at least to me):
>
> return a < b
> ? b < c
> ? b
> : a < c
> ? c
> : a
> : a < c
> ? a
> : b < c
> ? c
> : b
>
> Is this new syntax helping?
>
> return if a < b
> then if b < c
> then b
> else if a < c
> then c
> else a
> else if a < c
> then a
> else if b < c
> then c
> else b
>
> I found this translation quite tricky to do. maybe parens help?
>
> return (if a < b
> then (if b < c
> then b
> else (if a < c
> then c
> else a))
> else (if a < c
> then a
> else (if b < c
> then c
> else b)))
>
> Not really and I still I found this hugely frustrating, so much so that I
> am going to drop all support for this proposal and remove my name from it.
> If anyone wants to take over feel free.
>
> Others still keen on the idea should try this experiment. It convinced me
> is horrible idea :-) I don’t want to be blamed for it by every Swift
> programmer in the future.
>
> I do still however like the Swift Expressions.
>
> - Paul
>
>
>
> On Dec 14, 2015, at 4:50 PM, Nick Shelley via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> I however frequently hear people saying ternary should be avoided because
>> they are hard to read or they hate them.
>
>
> FWIW, I used to be one of those people, but then started working on a team
> where one member liked them. He didn't force them on us, but after enough
> code reviews where he showed us how to turn 5-line if/else statements into
> simple one-line ternary expressions, I got used to reading them and now
> love them and use them often.
>
> People also hate map, flatMap, reduce, etc., for the same reasons (it's
> hard for them to read because it's not the for loop they're used to). I
> think it's a simple matter of getting used to it.
>
> On Mon, Dec 14, 2015 at 11:57 AM, Chris Lattner via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>>
>> On Dec 14, 2015, at 12:19 AM, Paul Ossenbruggen via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>> Once again, thank you for all the feedback, if I sound in anyway grumpy
>> in responding to any email, it has a bit more to do with my cold than the
>> suggestions.
>>
>> I have split the original proposal into two proposals and incorporated a
>> bunch of feedback. Splitting it up has been extremely good, not only does
>> it improve readability, I am actually finding I could take or leave the
>> ternary replacement idea. But the proposal will be there if enough everyone
>> thinks it is a good idea. We could put it to a vote to see if there is
>> enough interest and I would be happy to take it further if there is. I
>> suspect this thread would not exist at all if there was no interest in it.
>> However, I am finding I am far more interested in getting switch
>> expressions.
>>
>> Ternary Replacement
>> https://github.com/possen/swift-evolution/blob/master/0021.md
>>
>>
>> Quick comment.  The proposal states:
>>
>>
>> Is it really better? Why not just keep ternary expressions?
>> This is a valid question, there is an advantage in compactness to ternary
>> expressions. I however frequently hear people saying ternary should be
>> avoided because they are hard to read or they hate them. There seems to
>> many who either stronly dislike it or don't care.
>>
>>
>> However, it doesn’t actually show that it is solving the objections
>> people have to the ternary operator.  It is true that some people find the
>> ?: syntax weird, but an equal number of people say that the problem is that
>> you’re putting complex conditional logic inline into the middle of an
>> expression - this proposal actually makes that objection worse.  There are
>> also other objections to ?:, and until you enumerate them, it is hard to
>> see whether this proposal is making things better or worse.
>>
>> -Chris
>>
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>>
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20151215/701e2d9b/attachment.html>