How to implement List, Set, and Map in null free design?
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by Pyrolistical
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Published on 2009-07-02T03:51:13Z
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2010/04/07
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Its great when you can return a null/empty object in most cases to avoid nulls, but what about Collection like objects?
In Java, Map
returns null
if key
in get(key)
is not found in the map.
The best way I can think of to avoid null
s in this situation is to return an Entry<T>
object, which is either the EmptyEntry<T>
, or contains the value T
.
Sure we avoid the null
, but now you can have a class cast exception if you don't check if its an EmptyEntry<T>
.
Is there a better way to avoid null
s in Map
's get(K)
?
And for argument sake, let's say this language don't even have null
, so don't say just use nulls
.
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