[swift-evolution] [swift-evolution-announce] [Review] SE-0099: Restructuring Condition Clauses

Brandon Knope bknope at me.com
Tue May 31 14:59:48 CDT 2016

Except "b" is the main focus of the where clause and b was just in the preceding if condition. 

I feel like we are trying to find ways to break the current where clause even though we've enjoyed it for almost a year now. I had no idea it was problematic and restrictive. I thought it made its intent very clear...leading to very readable code. 

Pretty soon almost every construct but conditionals will be allowed to have where clauses, and THAT seems inconsistent to me. 

...what exactly is the current problem? Can someone show me a real world example?? I've already forgotten it in all of this discussion -_-


> On May 31, 2016, at 3:47 PM, Xiaodi Wu via swift-evolution <swift-evolution at swift.org> wrote:
> On Tue, May 31, 2016 at 2:45 PM, Christopher Kornher via swift-evolution <swift-evolution at swift.org> wrote:
>>>> Not allowed:
>>>>>>>> let a = a
>>>> let b = b where b > 10 && a > 5
>>> Why would this not be allowed by your rule? You're making use of `b` in your where clause. As I demonstrated above, essentially any assertion can be rewritten to work around your rule. In general:
>> It is not allowed because  ‘a’ is defined in the line above. It must be defined in the ‘if let’ associated with the where in which it is mentioned.
> That's a much more restrictive where clause than you proposed earlier. You'd not be able to write:
> ```
> let b = b where b > anyOtherVariable
> ``` 
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