A Practical Minimum Distance Method for Syntax Error Handling

Original citation: Dain, J. A. (1992) A practical minimum distance method for syntax error handling. Copyright and reuse: The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available. Copies of full items can be used for personal research or study, educational, or not-for-profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Summary This paper presents a method for recovering from syntax errors encountered during parsing. The method provides a form of minimum distance repair, has linear time complexity, and is completely automatic. It is incorporated into the LR parser-generator yacc in such a way that a compiler writer can generate a parser with error recovery without providing any additional information to yacc. Error messages phrased in terms of source input are generated automatically. A formal method is presented for evaluating the performance of error recovery methods, based on global minimum-distance error correction. The minimum-distance error recovery method achieves a theoretically best performance on 80% of Pascal programs in the Ripley-Druseikis collection. Comparisons of performance with other error recovery methods are given.