I don't quite understand how to use the @enum macro in examples/enum.jl.
Could someone give an example that would have a similar effect to the C++
enum class Fruit { Apple, Banana};
auto f = Fruit::Apple;
Also, there is the @flags macro provided?
On Thursday, December 26, 2013 3:12:33 PM UTC-6, Stefan Karpinski wrote:
>
> That's a good approach if you're going to dispatch on the types, but if
> they're just values, we really should have something more like an enum. At
> this point, I'm thinking that @enum and @flags are good macros to have –
> where the @enum macro just defaults to 0, 1, 2, etc. while @flags defaults
> to 1, 2, 4, 8, etc. and defines bitwise operations on the flag values.
>
>
> On Thu, Dec 26, 2013 at 8:13 AM, andrew cooke <[email protected]<javascript:>
> > wrote:
>
>> great, thanks. a concrete example is just what i needed. andrew
>>
>>
>> On Thursday, 26 December 2013 00:06:07 UTC-3, Kevin Squire wrote:
>>
>>> The julia sort code might provide some guidance. It follows your last
>>> proposal, having an abstract type Algorithm, and a number of concrete,
>>> empty Algorithm subtypes (QuickSort, MergeSort, etc.), plus exactly one
>>> global constant instance of each of these subtypes. So, as you suggested,
>>> there is a little bit of setup overhead, but it allows you to use the
>>> "value" of the global constants for dispatch.
>>>
>>> Kevin
>>>
>>>
>>> On Wed, Dec 25, 2013 at 4:45 PM, andrew cooke <[email protected]> wrote:
>>>
>>>> I want to parametrize some code, so that it does one of three different
>>>> things, depending on the "value" of a parameter. The parameter is purely
>>>> symbolic - there's no corresponding numerical value.
>>>>
>>>> There's an enum.jl in examples and also some discussion of related
>>>> ideas in issues. But this isn't (yet) in the language, and anyway it
>>>> seems
>>>> crude (these are symbols, not numbers).
>>>>
>>>> There's also the possibility of using an abstract type and then three
>>>> concrete subtypes. That seems like too much work but, as far as I can
>>>> tell, is the way to "do" algebraic types in Julia (see list.jl example).
>>>>
>>>> I guess I am overthinking this. But what is the right approach?
>>>>
>>>> Thanks, Andrew
>>>>
>>>
>>>
>
