Configurable syntax

[Jason House]

bearophile Wrote:

> bearophile:
> > Having a return also helps to see templates as closer to compile-time functions (changing few things there may be ways to merge the syntax of templates with the syntax of compile time functions, reducing the complexity of D).<
> 
> To write some templates as compile-time functions you may need to add a new type to D, named "type":
> 
> type foo(type T) {
>     return T[];
> }
> 
> That is the same as:
> 
> template Foo(T) {
>     alias T[] Foo;
> }
> 

I'd love to see compile-time functions returning types. IMHO, it's far superior to the template-based approach. There are several reasons for this:

1. The template scheme violates the DRY principle. It's like type constructors in C++, Java, etc... D was designed to better than that! 

2. Function calls make it far clearer what the intent is. Once templates are allowed to have more members, the true purpose will be obfuscated.

3. It opens up possibilities for better (compile-time) reflection.

That being said, it's possible for templates to define an instance with unknown type and value. A non-templated function returning either a type or value can't do that.