Steven, I'd say its just for the useful error message
e.g.
abstract Parent
method1(p::Parent) = error("Children must implement this or face an error!")
method2(p::Parent) = error("Children must implement this or face an error!")
type Child <: Parent
fizz
buzz
end
method1(c::Child) = println("happy days")
# no method2, naughty
user code
jimmy = Child(1,2)
method2(jimmy) # Useful error message results that lets you know that you
SHOULD be able to do this, but can't due to a failure to implement in
library.
On Monday, February 24, 2014 10:27:16 AM UTC-5, Steven G. Johnson wrote:
>
> On Monday, February 24, 2014 9:55:33 AM UTC-5, Iain Dunning wrote:
>>
>> One way to do it is
>>
>> abstract Parent
>>
>> method1(p::Parent) = error("Children must implement this or face an
>> error!")
>>>
>>>
>>>>>
> How is this better than just deleting the method1(::Parent) method, in
> which case you will get a MethodError if one attempts to call it on a child
> type?
>
>
>
