A TOOL FOR THE AUTOMATIC ADAPTATION OF SOFTWARE COMPONENTS BASED
                 ON SEMANTIC SPECIFICATIONS

We describe the design and methods of a tool that, based on 
behavioral specifications in interfaces, automatically generates 
simple adaptation functors to overcome minor incompatibilities 
between SML modules. The transformations that get generated can 
be expressed in a small recursion-free sublanguage of SML, namely 
a typed lambda-calculus with function and record types, ML polymorphism, 
first-order type functions and SML equality types. The transformations 
are correct, they transform type- and behaviorally correct implementations 
of an interface A into type- and behaviorally correct implementations of 
an interface B. 

The hope is that a tool of this kind can be useful for automatically
overcoming incompatibilities that result from certain common interface 
changes in the evolution of software systems. Examples are changes 
that generalize functions by adding extra parameters, or changes that 
give functions different, but isomorphic, types. Such changes alter 
the types. The behavioral specifications, on the other hand, remain 
similar, and in many cases the similarities can be automatically 
recognized and the differences automatically overcome. Another possible 
application domain is in automatic library retrieval based on semantic 
specifications.