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https://issues.apache.org/jira/browse/COLLECTIONS-530?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Erik updated COLLECTIONS-530:
-----------------------------
    Comment: was deleted

(was: first implementation suggestion)

> Rejecting items on predicate failure without throwing an Exception
> ------------------------------------------------------------------
>
>                 Key: COLLECTIONS-530
>                 URL: https://issues.apache.org/jira/browse/COLLECTIONS-530
>             Project: Commons Collections
>          Issue Type: Improvement
>          Components: List
>    Affects Versions: 4.0
>            Reporter: Erik
>             Fix For: 4.x
>
>         Attachments: COLLECTIONS-530-v0.0.1.alpha.zip
>
>
> The PredicatedList class doesn't allow entries that fail the predicate, but 
> throws an Exception on entry.
> The problem I have with this, is that it places the onus of filtering out 
> invalid entries on the caller.
> I typically add items in a loop. The item added is the result of a method 
> call (which returns null if it can't create one).
> This problem is so common for me that I have created my own FilteredList 
> class that simply ignores invalid entries.
> I would like the PredicatedList class to be capable of rejecting items 
> without throwing an exception.
> I don't mind writing the code for this, but there are a great many ways in 
> which this can be done.
> So I was wondering what the interface should look like.
> Separate FilteredList class.
> Works, but seems a little verbose for the purpose
> New factory method: filteredList(List<T> list, Predicate<? super T> 
> predicate) 
> Nice and simple, but doesn't allow extension; other ways of dealing with 
> predicate failure.
> New factory method with enum: predicatedList(List<T> list, Predicate<? super 
> T> predicate, PredicateFailEnum action)
> More verbose to use and adds an extra class, but allows more alternative ways 
> to deal with predicate failure.
> One more nice thing is that it might be less confusing, 
> because choosing between predicatedList and the above filteredList might not 
> be so obvious.
> New factory method with interface: filteredList(List<T> list, Predicate<? 
> super T> predicate, PredicateFailInterface action)
> Complex, but the most flexible way of dealing with predicate failure.



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