String Interpolation

[duckchess]

On Saturday, 21 October 2023 at 18:25:22 UTC, Adam D Ruppe wrote:
> On Saturday, 21 October 2023 at 15:59:06 UTC, duckchess wrote:
>> can we just lower ```___""``` into ```mixin(___!"")```, where 
>> ```___``` can be any template name. this way you can implement 
>> whatever interpolation method you want in a library.
>
> https://github.com/adamdruppe/interpolation-examples/blob/master/01-basics.d
>
> I'll add more examples to that repo as I have time, but this 
> implementation allows libraries to do whatever methods they 
> want.

I understand your proposal, and YADIP is better than DIP1037 
imho. but it's adding a special case to the compiler and makes 
```string result = i"$name! See that DIP $dipNumber is easy to 
convert to string.".text;``` marginally better to write than what 
we can do today to have the exact same outcome ```string result = 
mixin(i!"$name! See that DIP $dipNumber is easy to convert to 
string.");``` where ```i``` would be a mixin template capturing 
the surrounding variables and returning an interpolated string.

if we just lower ```___""``` into ```mixin(___!"")```, we can 
write
```
import std.sinterp : i;
string s = i"$name! See that DIP $dipNumber is easy to convert to 
string.";
```

or

```
import std.sqlinterp : sql;
sqlstring s = sql"$name! See that DIP $dipNumber is easy to 
convert to string.";
```

and if there's no matching template, then we get a normal "i not 
found, did you forget to include std.sinterp?" error message.

there would be no need for the compiler to even know what string 
interpolation is. we'd have 'mixin strings'™.