[swift-evolution] for-else syntax

[Charlie Monroe]

+1

This is generally why I've suggested about a week or two ago "NonEmptyArray" - an array that ensures it's not empty. Which is IMHO a sensible thing to use sometimes instead...

> On Feb 1, 2017, at 8:38 PM, Sean Heber via swift-evolution <swift-evolution at swift.org> wrote:
> 
> I usually use guard (or sometimes if) and an early return:
> 
> func run() {
>  guard !names.isEmpty else {
>    /* stuff */
>    return
>  }
> 
>  /* stuff with names */
> }
> 
> l8r
> Sean
> 
> 
> 
>> On Feb 1, 2017, at 12:18 PM, Nicolas Fezans via swift-evolution <swift-evolution at swift.org> wrote:
>> 
>> I tend to write this kind of treatment the other way around...
>> 
>> if names.isEmpty {
>> 	// do whatever
>> } // on other cases I might have a few else-if to treat other cases that need special treament
>> else {
>> 	for name in names {
>> 		// do your thing
>> 	}
>> }
>> 
>> 
>> Nicolas Fezans
>> 
>> 
>> 
>> On Wed, Feb 1, 2017 at 6:31 PM, Saagar Jha via swift-evolution <swift-evolution at swift.org> wrote:
>> If you’re fine with a couple extra characters, you can use .isEmpty:
>> 
>> for name in names {
>> 	// do your thing
>> }
>> if names.isEmpty {
>> 	// do whatever
>> }
>> 
>> It’s a bit more typing, but I feel it makes your intentions more clear.
>> 
>> Saagar Jha
>> 
>>> On Feb 1, 2017, at 8:48 AM, Chris Davis via swift-evolution <swift-evolution at swift.org> wrote:
>>> 
>>> Hi,
>>> 
>>> Often when I’m programming I stumble upon this scenario:
>>> 
>>> I have a list of items that may or may not be empty - if it’s full, I do one thing, if it’s empty I do something else, my code looks like this:
>>> 
>>> class Example_1
>>> {
>>>    let names = ["Chris", "John", "Jordan"]
>>> 
>>>    /// Loop over names, if no names, print no names
>>>    func run()
>>>    {
>>>        for name in names
>>>        {
>>>            print(name)
>>>        }
>>> 
>>>        if names.count == 0
>>>        {
>>>            print("no names")
>>>        }
>>>    }
>>> }
>>> 
>>> let exampleOne = Example_1()
>>> exampleOne.run()
>>> 
>>> However, Personally, I would find it more pleasing to write something like this:
>>> 
>>> class Example_2_Proposed
>>> {
>>>    let names:[String] = []
>>> 
>>>    /// Loop over names, if no names, print no names
>>>    func run()
>>>    {
>>>        for name in names
>>>        {
>>>            print(name)
>>>        } else {
>>>            print("no names")
>>>        }
>>>    }
>>> }
>>> 
>>> let exampleTwo = Example_2_Proposed()
>>> exampleTwo.run()
>>> 
>>> The difference here is a “for-else” type syntax where if there were no items in the array it would simply fall through to the else statement.
>>> 
>>> What would be the pros/cons of introducing such syntax?
>>> 
>>> Is there’s a way of doing something similar in swift already?
>>> 
>>> Thanks
>>> 
>>> Chris
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> swift-evolution mailing list
>>> swift-evolution at swift.org
>>> https://lists.swift.org/mailman/listinfo/swift-evolution
>> 
>> 
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