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git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@4623 626c5289-ae23-0410-ae9c-e8d60b6d4f22
61 lines
2.7 KiB
Text
61 lines
2.7 KiB
Text
SWIG and Typesystems
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<h2>SWIG and Typesystems</h2>
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<p>
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For the past seven years, a considerable amount of effort has gone
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into the development of SWIG and its support for various programming
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languages. Currently, more than a <a href="guilty.html">dozen developers</a> work on the system
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and there are thousands of users. However, almost all of SWIG's development
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has been relatively ad-hoc---primarily driven by feature requests from
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users. As SWIG's original author, coordinating all of this chaos has
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always been a bit of challenge. In fact, it's been rather difficult to even
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describe what SWIG "is" and "how it works" without using terms like
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"magic" and, well, "more magic." Needless to say, this isn't the most
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academic way to look it ;-).
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<p>
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A little over a year ago, I became interested in the relationship
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between SWIG and work in the area of type systems. In order
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to support advanced C++ features like namespaces and templates, a
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significant amount of very difficult development work focused on the
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SWIG type system. Moreover, this work resulted in a lot of old SWIG
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features being folded into type system extensions. Because of this
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work, I have now come to view SWIG as being mostly driven as an
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extension of the C++ type system rather than an extension of a C++
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parser. This difference is subtle, but it is the only way to really
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understand how SWIG works at a fundamental level.
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<p>
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To the best of my knowledge, no one working on automatic C/C++ wrapper
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generators has really approached the wrapping problem from the
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standpoint of type systems. Instead, everyone seems to focus on the problem
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of <em>parsing</em> C++, which, although important, is not enough to
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really understand what is going on.
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<p>
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Starting in the summer of 2003, the NSF will be funding a
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<a href="http://www.fastlane.nsf.gov/servlet/showaward?award=0237835">research
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project</a> at the University of Chicago to explore the relationship
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between type-systems and wrapper generation in more detail. A lot of
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this work will involve SWIG and the semantics of its underlying type
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system. Moreover, this work will be exploring some exciting new
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features such as software contracts and improved mixed-language
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debugging support. We're also going to try and make connections
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between SWIG and related work in the area of programming languages.
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<p>
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What does this mean for the future of SWIG? Well, my hope is that
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this work will make the system more capable, more reliable, and more
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useful than ever. I think everyone will be pleasantly surprised with
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some of the changes.
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<p>
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As always, I'd like to acknowledge everyone who has contributed to SWIG
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over the years---thank you for your support!
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<p>
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Cheers,
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<p>
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Dave Beazley <br>
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March 23, 2003
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