Visual YACC is a tool that automatically creates visualizations of the YACC LR parsing process and synthesized attribute computation. The Visual YACC tool works by instrumenting a standard YACC grammar with graphics calls that draw the appropriate data structures given the current actions by the parser. The new grammar is processed by the YACC tools and the resulting parser displays the parse stack and parse tree for every step of the parsing process of a given input string.Visual YACC was initially designed to be used in compiler construction courses to supplement the teaching of parsing and syntax directed evaluation. We have also found it to be useful in the difficult task of debugging YACC grammars. In this paper, we describe this tool and how it is used in both contexts. We also detail two different implementations of this tool: one that produces a parser written in C with calls to Motif; and a second implementation that generates Java source code.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.