Re: [Caml-list] Ocaml clone detector
On Sep 3, 2009, at 8:06 AM, Nicolas barnier wrote: An amazing and simple technology to detect plagiarism is compression-based similarity distance. It is a side-effect of state-of-the-art compression algorithms that can be used to compute a distance for many kind of documents (it seems to work at least for program sources, books, music, DNA etc): take any two files A and B, compress A, compress B, and compress the concatenation of A and B, i.e. AB; take the size of these compressed files c(A), c(B) and c(AB); the similarity distance is simply d(A,B) = 1 - (c(A) + c(B) - c(AB)) / max (c(A), c(B)). Indeed, if documents A and B share information, the compression of AB will be much shorter than c(A) + c(B). Also see Alex Aiken's MOSS (measure of software similarity). It's online, language-specific, works for a variety of languages. Don't know how its algorithm compares to the one here. I suspect it's different insofar the one you describe is language-independent. John Clements ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] Ocaml clone detector
Kihong Heo wrote: I want to know there is a clone detector for Ocaml program. Maybe it would help if you explained what a clone detector is. Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] Ocaml clone detector
Erik de Castro Lopo wrote: Maybe it would help if you explained what a clone detector is. A clone is software-engineering speak for duplicated code. Exactly what qualifies as 'duplicated code' and how to efficiently find such (without too many false positives nor false negatives) is still fairly active research. This is a huge issue in languages without decent abstraction features, and less so otherwise (or so it seems). Jacques ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] Ocaml clone detector
Jacques Carette wrote: Erik de Castro Lopo wrote: Maybe it would help if you explained what a clone detector is. A clone is software-engineering speak for duplicated code. Exactly what qualifies as 'duplicated code' and how to efficiently find such (without too many false positives nor false negatives) is still fairly active research. This is a huge issue in languages without decent abstraction features, and less so otherwise (or so it seems). Thanks for the explanation. I can think of two situations where such a clone detector may be useful; for finding similar chunks of code so that they may be refactored for software QA management and for detecting plaguarism in student programming assignments. I suspect that these two kinds of clone detectors would actually be quite different. Cheers, Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] Ocaml clone detector
As far as student plagiarism goes, we found out that for Java
programs, you can pretty much detect frauds by erasing everything from
the programs except parentheses ( ) { } and then comparing the
remaining strings for editing distance. My explanation is that
students who copy code don't want to spend much time on it. In order
to chance the parenthesis they would have to understand the structure
of the program, which they don't.
Andrej
___
Caml-list mailing list. Subscription management:
http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list
Archives: http://caml.inria.fr
Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
Bug reports: http://caml.inria.fr/bin/caml-bugs
