Discussion Thread: DIP 1036--String Interpolation Tuple Literals--Community Review Round 2

[Steven Schveighoffer]

On 1/29/21 12:16 PM, Paul Backus wrote:
> On Friday, 29 January 2021 at 17:01:36 UTC, Steven Schveighoffer wrote:
>> On 1/29/21 10:49 AM, Paul Backus wrote:
>>> Once the `interp` instance passes through the implicit .stringof in 
>>> mixin(...), all of that semantic information is lost. Most of the 
>>> time you will get lucky and it will work anyway, but you have no 
>>> guarantee.
>>
>> mixin(i"int ${idname} = 5;"); will ALWAYS be rewritten to 
>> mixin(idup(i"int ${idname} = 5;"));
>>
>> If that is not clear in the DIP, it will be in the next update.
> 
> This directly contradicts what is written in the DIP, which is that if 
> the tuple expansion compiles successfully, it is used, and the idup 
> expansion is not attempted. If this is not what you intended, then the 
> DIP needs to be revised to reflect that.

Yes, I was not aware of the mixin parameter list acceptance. The 
intention was for it to convert to a string in that case. It will be 
fixed in an update as mentioned.

The intention is for the expanded version only to be used in template or 
function arguments.

-Steve