Design by Contract Model of a Software Component

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Design by Contract Model of a Software Component
Obligate the Environment
What data is necessary in response to the
event? What is the valid range of attributes for
each data element? Define the acceptable
states of the system after a components
operations are finished.
Precondition Axioms
Error Handler
Signature is require Precondition
do Method Body ensure
Postcondition rescue Rescue Clause
What data is necessary to recognize an
event? What is the valid range of attributes
for each data element? Define only
acceptable conditions for a components
operation to begin.
Postcondition Axioms
Obligate the Component
Error Handler
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Structured Algebraic Specification
Chapter 8 Software Engineering Fourth Edition,
Ian Sommerville, Addison-Wesley, 1992.