suggestion: relaxing reqirements for version and mixin

[Chris Nicholson-Sauls]

Dan wrote:
>>>> Thomas Kuehne wrote:
>>>>> if( version(STRICT){a<200 || } a>0){
>>>>>     // blabla
>>>>> }
>>>> Both those features smack of textual processing to me.
>>>>
>>>> "Modern languages should not be text processing, they should be symbolic 
>>>> processing."
> 
> To me, that looks like the way it ought to be.
> 
> It also makes sense to me to allow:
> 
> x = switch(y){  <-- ask me about the implementation
>   case 3: 5;
>   case 2: 4;
>   case 7: 3;
>   default: 1;
> }

T match (T, U) (T val, T[U] pairs, T def = T.init) {
   if (auto ptr = val in pairs)
     return *ptr;
   else
     return def;
}

Okay, so it isn't ideal -- and admittedly just came off the top of my head -- but the idea 
is, ultimately, the same.  Maybe it can be leveraged into something more generally useful? 
  Random thought.  :)

> and 
> 
> double myFunc(double x)
>    return std.math.log2E(x)+1;

I've got no problem with this at all.  A hypothetical scripting language I toyed with for 
a few months did something rather like it:
   function myFunc (x) = #Math:log2E(x) + 1;

Note the absence of a 'return' keyword.  The concept was that, in the case of an 
expression statement, the result of the expression would be automatically returned.  But 
again, that was for a scripting language, so D may or may not be able to get away with 
that cleanly.

> for(int i = 0; i < 100; i++)
>    x += myArray[i] - (myOtherArray[i] * i);

Okay, I must be dense (quite likely, really) but I don't recall for() statements not 
allowing bodies without braces?  The specs still describe them as allowing 
single-statement bodies, and my own code has a few of these here and there.  Did I miss 
something radical?

> Why?  
> 
> For the latter two, we allow if's to be done that way.  But not for loops or functions?  Sure it's text processing.  We're feeding the compiler text instructions!  I agree, it's a bad idea to get into macro'ing - templates are already too far into that, and I don't use mixins.
> 
> These are just sensible completions of the language.

-- Chris Nicholson-Sauls