Union types (Sum types, really) shine when used with pattern matching and
exhaustion check.
This is not provided by this proposal.
Without that, there are already a number of ways to encode them in Groovy.
-1
Dierk
sent from:mobile
> Am 23.07.2017 um 02:13 schrieb MG <mg...@arscreat.com>:
>
> Since this feature would have been helpful to me on several occasions
> (avoiding to have to introduce an interface or go dynamic) I would
> tentatively have said +1.
> Tentatively, because I am at the same time worried that a feature like that
> could prevent framework developers from introducing a meaningful interface
> hierarchy, over time possibly leading to code like
> void
> doGenericStuff(DeviceManager|VerySpecializedClassWithLongName|TautologicalFluxCompensatorMatrixElement|KungFooMaster
> x) { ... }
> On the other hand, IDE refactoring support could allow for automatic
> extraction of a shared functionality interface between the given classes
> here...
>
> I would also have thought of the exact same syntax - can you explain why you
> think it would break future extensions, Paul ?
> mg
>
>> On 23.07.2017 01:50, Paul King wrote:
>> I would be leaning towards -1 without further justification. Even though I
>> don't think we want to rush into union types in Groovy, wouldn't this syntax
>> rule out us having it down the track?
>>
>> Cheers, Paul.
>>
>>
>>> On Sun, Jul 23, 2017 at 8:28 AM, Daniel Sun <realblue...@hotmail.com> wrote:
>>> Hi all,
>>>
>>> I've been thinking about Union Type for method/constructor
>>> declaration. It is similar to multi-catch in try-catch
>>> statement, e.g.
>>>
>>> class UnionTypeSample {
>>> public UnionTypeSample(A|B|C p) {
>>> // do something
>>> }
>>>
>>> def m(D|E p) {
>>> // do something
>>> }
>>> }
>>>
>>> Groovy will translate the above code into the following code, which is
>>> also the same way how multi-catch is handled.
>>>
>>> class UnionTypeSample {
>>> public UnionTypeSample(A p) {
>>> // do something
>>> }
>>>
>>> public UnionTypeSample(B p) {
>>> // do something
>>> }
>>>
>>> public UnionTypeSample(C p) {
>>> // do something
>>> }
>>>
>>> def m(D p) {
>>> // do something
>>> }
>>>
>>> def m(E p) {
>>> // do something
>>> }
>>> }
>>>
>>> Any thoughts?
>>> ----------------------------------
>>> [+1] I like it
>>> [ 0] Not bad
>>> [-1] I do not like it
>>> ----------------------------------
>>>
>>> Cheers,
>>> Daniel.Sun
>>>
>>>
>>>
>>> --
>>> View this message in context:
>>> http://groovy.329449.n5.nabble.com/VOTE-About-the-Union-Type-for-method-constructor-declaration-tp5742265.html
>>> Sent from the Groovy Users mailing list archive at Nabble.com.
>>
>
