Abstract type: Difference between revisions
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def !valid?(object) nil |
def !valid?(object) nil |
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tag AbstractStack some-object ; always fails |
tag AbstractStack some-object ;# always fails</lang> |
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*** Error: class AbstractStack validator error for some-object ...</lang> |
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However this is not much use if we want to use an abstract class to define an interface. Here is a quasi-abstract class which can be used to tag objects if they conform to the class's membership expectations. In this case it wants two methods, !enstack and !destack: |
However this is not much use if we want to use an abstract class to define an interface. Here is a quasi-abstract class which can be used to tag objects if they conform to the class's membership expectations. In this case it wants two methods, !enstack and !destack: |
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