How to complex switch?

[KennyTM~]

On May 12, 11 19:13, Matthew Ong wrote:
> Hi All,
>
> Anyway to include this cool feature of switch with D in the near future?

Why the obsession with 'switch'? 'if' works fine.

>
> switch(str){
>                     // regexp
> case "abc", "def", "as+b?": s1(); break;
>
> case "za+", "wd?", "aaa": s2(); break;
>
> default: s3();
> }

Regex isn't even a built-in feature, why would a 'switch' should support it.

if (match(str, regex("abc|def|as+b?"))
   s1();
else if (match(str, regex("za+|wd?|aaa"))
   s2();
else
   s3();

>
> switch (tag) {
> default: s3()
> case 0, 1, 2, 3: s1()
> case 4, 5, 6, 7: s2()
> }
>

Already possible (except you're missing the 'break;')

> switch (x := f();) {  // missing switch expression means "true"
> case x<  0: return -x
> default: return x
> }

Please no. Why introduce yet another operator ':=' ?!

auto x = f();
if (x < 0)
   return -x;
else
   return x;

>
> switch (x){
> case x<  y: f1()
> case x<  z: f2()
> case x == 4: f3()
> case z+y: f4()
> }

Assume you don't mean to fall-through

if (x < y)
    f1();
else if (x < z)
    f2();
else if (x == 4)
    f3();
else if (x == z+y)
    f4();