Pattern matching in D

[Simen kjaeraas]

Walter Bright <newshound1 at digitalmars.com> wrote:

>> foo match {
>>   case b: Bar => b.doBarMethod
>>   case b: Bar2 => b.doBar2Method
>>   case _ => println("Oh no!")
>> }
>>  (1, (1,2)) match {
>>   case (1, (1, _)) => println("nice tuple")
>>   case _ =>
>> }
>>  def main(args: Array[Byte]) =
>>   args(0) match {
>>     case "-help" => println("Usage: ...")
>>     case "-moo" => println("moo")
>>   }
>
> D already supports string switches.

Which means that D supports array switches (untested code):

switch( (string)foo ) {
   case (string)[1,2,3]: doSomething( );
   case (string)[3,2,1]: doSomethingElse( );
}

Might require some tweaking, but I believe this would work. Not saying  
it's a good idea, though.

As for structs:

switch ( foo.toHash( ) ) {
   case S(1,2,3).toHash( ): doSomething( );
   case S(3,2,1).toHash( ): doSomethingElse( );
}

If toHash is CTFE-able. Just as untested, and might not work at all.

-- 
Simen