Re: Traits with interfaces

This cannot work for a number of reasons: - a trait is not a type, and does not practically exist at runtime - trait defined API can be imported with changed/aliased names, breaking therefore the contact defined in the interface - due to the previous point, inheriting a type from a trait becomes a dangerous BC boundary, easily broken by consumers of the trait when consumers alias or when the trait implementor adds a new interface implementation My general suggestions: - don't use traits - don't use traits - also, don't use traits - remember to not use traits - traits: don't - things you shouldn't use on Betelgeuse and other systems: traits Besides jokes, inheriting signatures together with implementations (inheritance, abstract types) is less and less endorsed in the PHP ecosystem, as it just increases coupling by a huge lot. At least from my own experience, things are finally moving towards more composition over inheritance. On 28 Feb 2018 21:58, "David Rodrigues" <david.proweb@gmail.com> wrote: > Why traits doesn't supports interfaces (via implements) like classes does? > > It could be useful when trait implements part of abstract functions from > interface, then the class that uses this traits should implements the > another part. > > It could turn it possible (pseudo-code): > > interface VisibilityControlContract > - public function isVisible(): bool; > > trait VisibilityControlTrait implements VisibilityControlContract > - public function isVisible(): bool { ... } > > class UserModel (not need implements VisibilityControlContract directly) > - uses VisibilityControlTrait; > > var_dump(new UserModel instanceof VisibilityControlContract); // true > > The disvantages that I can see with that is that without an IDE I could not > identify easily if interface was implemented by some trait. But it too > happen when I do implements an abstract class that implements some > interface. > > -- > David Rodrigues >