Why can't we derive struct's? (Hansel & Gretel)

[Atila Neves]

On Friday, 21 December 2018 at 03:33:05 UTC, Walter Bright wrote:
> On 12/20/2018 10:38 AM, H. S. Teoh wrote:
>> There has been multiple attempts to implement it, but none were
>> persistent enough to see it through to the finish line.
>
> Nobody has figured out the semantics of single alias this, 
> either (when faced with class inheritance). The bugzilla issues 
> for it are ample evidence.
>
> MI is a Hansel and Gretel feature, where it appears to be all 
> gingerbread and candy, but the witch inevitably appears to pop 
> you in the oven.
>
>
> Other Hansel and Gretel features:
>
> 1. monkey patching
> 2. macros
> 3. implicit variable declaration
> 4. preprocessor

I don't think any lisper has ever complained about Lisp macros - 
on the contrary, it's considered one of Lisp's killer features. 
It's a shame they're inextricably linked to the syntax (or lack 
thereof) and that nobody has yet figured out a good macro system 
that doesn't depend on S-expressions.