Abstract methods in ruby ?

[cypher.dp]

Hi everybody !

How do you implement something like the "abstract" keyword in Java ?
Or: Is there a technique to force a subclass to implement a special method ?

Kind regards

Dominik

 

[James Edward Gray II]

How do you implement something like the "abstract" keyword in Java ?
Or: Is there a technique to force a subclass to implement a special
method ?

One way is:

class Parent
def abstract_method
raise NotImplementedError
end
end

You may just want to skip this step altogether though, since an
exception toss is the default behavior.

Welcome to the word of dynamic typing.

James Edward Gray II

 

[cypher.dp]

Thanks a lot for the warm welcome, James

One way is:

class Parent
def abstract_method
raise NotImplementedError
end
end

You may just want to skip this step altogether though, since an
exception toss is the default behavior.

Welcome to the word of dynamic typing.

James Edward Gray II

 

[Thomas Hafner]

Or: Is there a technique to force a subclass to implement a special method ?

Alternatively try something similiar to the the NVI idiom in C++:

# interface
module MyInterface
def foo(*args, &block)
do_foo(args, block)
end
end

# special implementation of interface
class MyClass
include MyInterface

private
def do_foo(args, block)
# TODO complete implementation
end
end

Regards
Thomas