3
- types -- as an organizing principle
- contracts -- obligations and benefits
- subtyping -- the substitutability requirement
- partial types -- designed to have subtypes
slide: Section 3.3: Contracts
The object model resulting from
an initial exploration may be formalized
by employing types.
In section 3, we discussed the notion of contracts
as a means to characterize the behavioral
aspects of types,
specifying the restrictions and obligations
of an object and its clients.
We also looked at the requirements
for subtype refinement and the refinement of contractual obligations.
4
- contracts -- formal specification
- verification -- as a design methodology
- runtime consistency -- invariance
slide: Section 3.4: Towards a formal approach
Finally, in section 4, we reflected on the possible
contribution of formal methods to
the software engineering of
object-oriented systems,
and concluded that the notion of
contracts may play an invaluable role,
both as a design methodology and as
a means to establish the runtime
consistency of a system.
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readme
course
preface
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appendix
lectures
resources
eliens@cs.vu.nl

draft version 0.1 (15/7/2001)