Proposal: Dedicated-string-mixin templates/functions

Pelle Månsson pelle.mansson at gmail.com
Fri Feb 5 05:07:05 PST 2010


On 02/05/2010 12:13 PM, Nick Sabalausky wrote:
> Point #1: It's often been noted that string mixin syntax is ugly. Which is a
> bad thing in and of itself, but it also tends to discourage use of string
> mixins despite their high degree of usefulness.
>
> Point #2: It seems to me that the vast majority of templates and functions
> are either designed specifically to be used as a string mixin or
> specifically designed to be used as something other than a string mixin.
> Only rarely does a single template or function seem to be particularly
> useful both ways.
>
> Proposal:
> So how about taking a cue from Nemerle:
>
> Current:
> -----------------------
> template foo1 {
>      const char[] foo1 = "int a;";
> }
> char[] foo2() {
>      return "int b;";
> }
> mixin(foo1!());
> mixin(foo2());
> -----------------------
>
> Proposed:
> -----------------------
> mixin template foo1 {
>      const char[] foo1 = "int a;";
> }
> mixin char[] foo2() {
>      return "int b;";
> }
> foo1!();
> foo2();
> -----------------------
>
> One consequence of this worth noting is that the current string-mixin could
> be trivially recreated under the proposed syntax:
>
> -----------------------
> mixin char[] mixinString(char[] str) {
>      return str;
> }
> mixinString("int a;");
> -----------------------
>
> Maybe someone not as half-asleep as I currently am can point out a
> clean/clever way to retrieve the string value of such a template/function
> without actually mixing it in, to cover the occasional cases where that
> actually would be useful.
>
>

I agree, for the mixin template part at least.

Then we just need a cleaner way to "return" things from templates, and 
we'll be all good.



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