Microsoft Word OpenIssuesInOO. doc

Class versus module. There seem to be some disagreement on to what extent class and 

module should be the same mechanism. Eiffel requires them to be the same and many 

other object-oriented languages do not  have a special module mechanism. In C++ a 

module is really a file. In BETA there is a special language independent system for 

supporting modularisation [KMMN83b, MMN93]. In Reference [Szy92] it is argued 

that class and module are two different mechanisms. Self [Ung95] also has a 

modularisation mechanism that supports splitting the slots of an object into different 

modules. 

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Exceptions. Each object-oriented languages has its own exception handling 

mechanism, but most of them  are based on a dynamic approach similar to the one 

originally proposed in Reference [Goo75] and found in e.g. Ada. In BETA exception 

handling is based on a static approach defined using patterns [Knu84]. 

The following issues deserve more attention, since they may contribute to a qualitative 

improvement of object-oriented programming: 

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Reflection. For a number of years, reflection [Smi84] has been a research issue, but it 

has had little impact on main-stream object-oriented languages. Notable exceptions are 

CLOS and Self.  

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