Visual language implementation through standard compiler–compiler techniques

We present a technique for implementing visual language compilers through standard compiler generation platforms. The technique exploits eXtended Positional Grammars (XPGs, for short) for modeling the visual languages in a natural way, and uses a set of mapping rules to translate an XPG specification into a translation schema. This lets us generate visual language parsers through standard compiler–compiler techniques and tools like YACC. The generated parser accepts exactly the same set of visual sentences derivable through the application of XPG productions. The technique represents an important achievement, since it enables us to perform visual language compiler construction through standard compiler–compilers rather than specific compiler generation tools. This makes our approach particularly appealing, since compiler–compilers are widely used and rely on a well-founded theory. Moreover, the approach provides the basis for the unification of traditional textual language technologies and visual language compiler technologies.