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

[Steven Schveighoffer]

On 1/31/21 10:54 AM, Andrei Alexandrescu wrote:
>> Try to please everybody and you end up pleasing nobody. 
> ...
>> DIP1027 works with writef, and I consider that to be the goal, not 
>> printf.
> 
> Unpopular opinion follows (at this point I have no idea which side of 
> the debate this puts me on).

I don't think it's unpopular, or wrong. I 100% agree with your assessment.

> But wait! one might say in response. What if I need on occasion some 
> special formatting of one argument in one of them nice interpolated 
> strings? No problem, I say. Do what Perl, PHP, and Python programmers 
> have done for millenia - apply the formatting function separately for 
> the desired argument:
> 
> i"Hello, ${format(`%45s`, var)} world"!

This is how I would do it:

i"Hello, ${var.withFormat!"%45s"} world";

(where withFormat provides a toString overload that works with idup). No 
extra intermediate allocations necessary.

-Steve