Package pi provides the top-level repository for the GoPi interactive parser system. The code is organized into the various sub-packages, dealing with the different stages of parsing etc. * pi: integrates all the parsing elements into the overall parser framework. * langs: has the parsers for specific languages, including Go (of course), markdown and tex (latter are lexer-only) * filecat: is the core file categorization (e.g., mime-type, etc) framework that associates files with their extensions and provides other type-level meta data that enables the Pi system and GoGi and other GoKi framework tools to know how to deal with different types of files. Note that the GUI editor framework for creating and testing parsers is in the Gide package: https://github.com/goki/gide under the piv sub-package.