Just another example of missing string interpolation

[Steven Schveighoffer]

On Friday, 20 October 2023 at 08:03:55 UTC, Walter Bright wrote:
> On 10/19/2023 6:52 PM, Steven Schveighoffer wrote:
>> The point is that it's too easy to match to strings, compile, 
>> and do a completely unexpected thing. And yes, that's the 
>> major reason why 1027 is so bad.
>
> I don't recall this issue even being discussed in the old 
> review of it. It isn't listed in the review objections for 
> DIP1027.

No it's not listed (which surprises me), and the thread is huge, 
I don't feel like going through it all.

I do remember objecting to it though, on the grounds that you 
can't overload based on a string.

For example, I have in mysql-native a function:

```d
ulong exec(T...) (Connection conn, const(char[]) sql, T args)
```

Which accepts the statement in the mysql format of using `?` for 
placeholders. In order to accept an interpolation tuple, I'd have 
to name a new function:

```d
ulong execi(T...) (Connection conn, const(char[]) sql, T args)
```

Which then forwards to the real `exec`. And there would be no way 
for the compiler to prevent the user from using either with the 
incorrect parameters. *AND* the `execi` function needs to parse 
the format string at runtime replacing "%s" with "?".

Whereas, YAIDIP and DIP1036 provide a way for the `exec` function 
to be overloaded with interpolation literals, and always do the 
right thing at pretty much no runtime cost (the building of the 
string can be at compile-time).

> But I undestand you don't like this, and there is a rather nice 
> solution. Recall Andrea Fontana's example:
>
> ```
> void deleteFiles(string[]... files) { ... }
> ```
>
> As a special case, an i-string will not be a match for 
> `string[]...`. This makes sense, as a function requiring a 
> format string would not be expecting no string. A match would 
> have to be of the form:
>
> ```
> void deleteFiles(string fmt, ...) { ... }
> ```

Just another whacked mole? What about the Exception problem?

```d
throw new Exception(i"Invalid integer value in $file: $val");
```

-Steve