Runtime evaluation

[David Nadlinger]

You could generate the if/else-chain, lookup table, etc. via 
metaprogramming to save you the typing and code duplication (probably a 
foreach over std.traits.EnumMembers will be involved).

David


On 7/7/11 11:23 PM, nrgyzer wrote:
> Hi guys,
>
> I'm trying to read a string from a text file which contains a value of an enumeration like:
>
> enum MyEnum : string {
>     Entry_1 = "abc",
>     Entry_2 = "def",
>     Entry_3 = "ghi",
> }
>
> Stream s = new File("myFile.ext", FileMode.In);
> uint len;
> s.read(len);
> string entry = cast(string) s.readString(len);
> s.close();
>
> writeln(mixin("MyEnum." ~ entry));
>
> myFile.ext may contain:
> ...
> Entry_2
> Entry_1
> Entry_2
> Entry_3
> ...
>
> But mixin's are for compile time only... is there any chance to do this or do I've to use another method (like if/else or switch/case):
>
> if (entry == "Entry_1") ...
> else if (entry == "Entry_2") ...
> ...
>
> Thanks a lot!