[swift-evolution] [Proposal Draft] Literal Syntax Protocols

[Sean Heber]

IntegerLiteralExpressable?

Does Apple employ any philosophers? We might need one...

l8r
Sean

Sent from my iPad

> On Jun 28, 2016, at 10:02 PM, Erica Sadun <erica at ericasadun.com> wrote:
> 
> 
>> On Jun 28, 2016, at 8:08 PM, Sean Heber <sean at fifthace.com> wrote:
>> 
>> What about..
>> 
>> Syntax.ConvertibleFromIntegerLiteral
>> etc..
> 
> I like it but Dave has already expressed that this isn't conversion. This
> is something distinct, magical, and more importantly, ineffable.
> 
> He says it means an instance of the type can be written as a literal, and
> not converted from a literal. He writes:
> 
>> Conformance to this protocol does *not* mean you can initialize the type with
>> a literal. 
>> 
>> Proof:
>> 
>> func f<T: IntegerLiteralConvertible>() -> T {
>>   return T(integerLiteral: 43) // Error
>>   return T(43)                 // Also an Error
>> }
>> 
>> It means an instance of the type can be *written* as a literal:
>> 
>> func f<T: IntegerLiteralConvertible>() -> T {
>>   return 43   // OK
>> }
>>> 
> 
> So we're looking at something more like:
> 
> Syntax.AnIntegerLiteralCanBeSubstitutedForThisTypeAndTheCompilerWillNotBarf
> 
> -- E
> 
>