CSC/ECE 517 Fall 2010/ch6 6b yc: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
<div class="usermessage hideme" align="center" style="font-size:16pt"><b>Support for Assertions in Various O-O Programming Languages</b></div> | |||
= Problem Statement = | = Problem Statement = | ||
"Compare the support for assertions in various o-o programming languages. How well is it integrated with the language (instead of being supplied by libraries)? How many kinds of assertions are supported? How are assertions used in the various flavors of xUnit testing frameworks?" | "Compare the support for assertions in various o-o programming languages. How well is it integrated with the language (instead of being supplied by libraries)? How many kinds of assertions are supported? How are assertions used in the various flavors of xUnit testing frameworks?" | ||
| Line 9: | Line 11: | ||
Assertions are formal constraints on software systems which are inserted as annotations in the source program text. They had their origin in program verification [2]. Program correctness is usually defined in relation to a specification and assertions can encode the semantic properties of a specification. Using assertions to show program correctness is in general a non-trivial task and therefore it is hardly followed in practice. However, many key properties of a program can still be encoded in a simple assertion language. In such a scenario, if a program executes without any assertion violation, it can give some confidence about the program’s correctness. In a sense, assertions test a program without using any test data. | Assertions are formal constraints on software systems which are inserted as annotations in the source program text. They had their origin in program verification [2]. Program correctness is usually defined in relation to a specification and assertions can encode the semantic properties of a specification. Using assertions to show program correctness is in general a non-trivial task and therefore it is hardly followed in practice. However, many key properties of a program can still be encoded in a simple assertion language. In such a scenario, if a program executes without any assertion violation, it can give some confidence about the program’s correctness. In a sense, assertions test a program without using any test data. | ||
== Example == | |||
Revision as of 14:49, 17 November 2010
Problem Statement
"Compare the support for assertions in various o-o programming languages. How well is it integrated with the language (instead of being supplied by libraries)? How many kinds of assertions are supported? How are assertions used in the various flavors of xUnit testing frameworks?"
Introduction
Definition
"An imperfect solution is better than none. - B. Meyer "[1]
Assertions are formal constraints on software systems which are inserted as annotations in the source program text. They had their origin in program verification [2]. Program correctness is usually defined in relation to a specification and assertions can encode the semantic properties of a specification. Using assertions to show program correctness is in general a non-trivial task and therefore it is hardly followed in practice. However, many key properties of a program can still be encoded in a simple assertion language. In such a scenario, if a program executes without any assertion violation, it can give some confidence about the program’s correctness. In a sense, assertions test a program without using any test data.
Example
References
- [1] B. Meyer, Object Oriented Software Construction, Prentice Hall, 1997.
- [2] C. A. R. Hoare, An Axiomatic Basis for Computer Programming, Communications of the ACM, Vol. 12, No. 10, pp. 576–580,583, October 1969.