[swift-evolution] Proposal: Optional Binding Shorthand Syntax

[Zef Houssney]

Thanks for your thoughts David!

I would argue that it does support stated objectives of Swift, like "the syntax is concise yet expressive.”

In the majority of cases having a lot of esoteric syntax is a problem. However, with this being such a fundamental part of every day programming in Swift, I find it to be a perfect place to reduce friction. I also find it to be quite understandable and intuitive, unlike the three examples of Swift 3 changes that you gave, which are more specialized and less frequently encountered.

Also, I just noticed that this isn’t unprecedented and that a similar idiom actually currently used in Swift to assign constants when pattern matching inside a Switch:

case let (x, y):

That is doing fundamentally the same thing that I’m suggesting. It assigns a constant without using `=`, because the value is already known.

Zef



> On Dec 3, 2015, at 1:26 PM, David Hart <david at hartbit.com> wrote:
> 
> I understand the reasoning of this proposal but it seems to go against the objectives the Swift team has been striving towards lately of:
> 
> - simplifying the language
> - making code more explicit by removed by shorthand syntax
> - removing redundant syntax for achieving the same behavior 
> 
> You can see examples of this in the latest changes to the language:
> 
> - removal of the # symbol in the first argument name as a shorthand to defining the argument name twice
> - removal of the ++ and -- prefix and postfix operators in Swift 3
> - removal of the var modifier in argument declaration and if/guard/while/for in blocks in Swift 3
> 
> I tend to agree with their philosophy to remove these shorthand syntaxes which make the language more difficult to learn (when all these features are taken as a whole) and potentially making the grammar more complicated only for the benefit of a shorthand syntax which also has the disadvantage of allowing two different syntaxes for the same semantics.
> 
> Just my 2 cents :)
> 
> 
> 
> Sent from my iPhone
>> On 03 Dec 2015, at 20:52, Zef Houssney <zefmail at gmail.com> wrote:
>> 
>> Hello. This is exciting!
>> 
>> I have an idea I’ve been mulling over for a while to reduce a common source of clutter in Swift code.
>> 
>> The idea is to introduce a new syntax for Optional Binding:
>> 
>> Instead of:
>> 
>> if let foo = foo { } 
>> 
>> You could simply use:
>> 
>> if let foo { } 
>> 
>> 
>> I’ve written up a draft of a proposal here with additional information and motivations:
>> https://github.com/zef/swift-evolution/blob/master/proposals/00xx-optional-binding-shorthand.md
>> 
>> 
>> What do you think?
>> 
>> Thank you!
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