Writing a parser remains remarkably painful. Automatic parser generators offer a powerful and systematic way to parse complex grammars, but debugging conflicts in grammars can be time-consuming even for experienced language designers. Better tools for diagnosing parsing conflicts will alleviate this difficulty. This paper proposes a practical algorithm that generates compact, helpful counterexamples for LALR grammars. For each parsing conflict in a grammar, a counterexample demonstrating the conflict is constructed. When the grammar in question is ambiguous, the algorithm usually generates a compact counterexample illustrating the ambiguity. This algorithm has been implemented as an extension to the CUP parser generator. The results from applying this implementation to a diverse collection of faulty grammars show that the algorithm is practical, effective, and suitable for inclusion in other LALR parser generators.
Wed 17 Jun
|16:00 - 16:25|
Stefan MarrInria, France, Chris SeatonOracle Labs / University of Manchester, Stéphane Ducasse INRIA LilleMedia Attached
|16:25 - 16:50|
|16:50 - 17:15|
Alan LeungUniversity of California, San Diego, John SarracinoUniversity of California, San Diego, Sorin LernerUniversity of California, San DiegoMedia Attached
|17:15 - 17:40|