A Practical Method for Syntactic Error Diagnosis and Recovery

Abstract

Our goal is to develop a practical syntactic error recovery method applicable within the general framework of viable prefix parsing. Our method represents an attempt to accurately diagnose and report all syntax errors without reporting errors that are not actually present. Successful recovery depends upon accurate diagnosis of errors together with sensible “correction” or alteration of the text to put the parse back on track. The issuing of accurate and helpful diagnostics is achieved by indicating the nature of the recovery made for each error encountered. The error recovery is prior to and independent of any semantic analysis of the program. However, the method does not exclude the invocation of semantic actions while parsing or preclude the use of semantic information for error recovery.