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From: bertrand@eiffel.UUCP (Bertrand Meyer)
Newsgroups: comp.lang.eiffel
Subject: Re: How can I do this in Eiffel?
Summary: Reuse library class
Message-ID: <529@eiffel.UUCP>
Date: 16 Apr 91 01:25:39 GMT
References: <ajk.671419932@wren>
Distribution: comp
Organization: Interactive Software Engineering, Santa Barbara CA
Lines: 18

From <ajk.671419932@wren> by ajk@wren.cs.rmit.OZ.AU (Alan Kent):
> Can someone tell me if I am missing something obvious? I cannot see how to
> do this nicely in Eiffel.
> 
> [Description of a need to iterate variously over trees]

Reuse class C_TREE_ITER from the Iteration Library. If you need
several types of iteration in the same context, use repeated
inheritance.

If the assumptions made by that class do not conform to your particular
type of tree, and you do not want to change your data structures,
imitate and adapt the ideas from C_TREE_ITER and other
iteration classes from the library. If this happens please
tell us (eiffel@eiffel.uucp) about your experience so that we
can improve the library; or, better yet, submit an improved version
to the Eiffel shelf, the mechanism for distributing reusable software
components (shelf@eiffel.uucp).

-- Bertrand Meyer
Interactive Software Engineering Inc., Santa Barbara
bertrand@eiffel.uucp