On 2016-02-05 15:23:53 +0000, Marc Schütz said:
Does the following help?
...
I thought about it too, but I need it to work with more then one
parameter, so I tried this which doesn't work:
Value nativePlus(Value a, Value b){
// @@ not working, runtime exception
castSwitch!(
(IntV a) {
castSwitch!(
(IntV b) {return new IntV(a.num + b.num);}
)(b);
},
(StringV a) {return new StringV("string plus");},
)(a);
// to keep compiler happy when using castSwitch (has no return statement)
return new UnsetV();
}
and ended with this, which works and is straight forward but maybe not
that elegant:
Value nativePlus(Value a, Value b){
if(cast(IntV) a && cast(IntV) b)
return new IntV((cast(IntV)a).num + (cast(IntV)b).num);
if(cast(StringV) a && cast(StringV) b)
return new StringV((cast(StringV)a).str ~ (cast(StringV)b).str);
// if no case was hit (could throw)
return new UnsetV();
}
Can this be written simpler or more elegant?
I read this here:
https://github.com/D-Programming-Language/phobos/pull/1266#issuecomment-53507509
(functional pattern matching) but it seems it won't be implemented...
at the end of the day what I simulate are poor-mans-multimethods
--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster
