Geppetto

Geppetto brings partial behavioral reflection to Squeak!


It allows to reify different operations like message send, message receive or field access (read and write). Upon such operation occurrences at runtime a shift to the meta-level may occur where user-defined metaobjects can react on these occurrences. The call to the metalevel may occur before, after or instead of the normal operation occurrence.


The Geppetto Framework allows to create a new MOP, adapted to the needs of a user, but it might be enough to use the powerful standard MOP in most cases.


The operation occurrences on which a metaobject should be called can be specified in a very find-grained manner, at class level, at instance level and even intra-operational. The mechanisms to specify the desired operation occurrences are quite expressive.


Furthermore one can specify which information should be reified. Because reification is expensive, it's always reasonable to just reify these pieces of information that are needed on the metalevel.