Synopsis parses source code into a variety of internal representations (IRs), which then are manipulated in various ways, before some output (such as a cross-referenced API documentation) is generated by an appropriate formatter.
At the core of Synopsis are a set of programming-language independent IRs which all parser frontends generate. One of these representations is the Abstract Semantic Graph, which stores declarations and their relationships. Another is the SXR Symbol Table, which stores information about symbols and their use in the source code. Other representations exist (such as the C++ Parse Tree), but they are not yet stored in a publicly accessible form.
For details about the ASG, see the section called “The ASG”
At this time, the C++ frontend's IRs (PTree, SymbolTable, etc.) are not yet accessible through python, though they eventually will be, making it possible to use Synopsis as a source-to-source compiler. To learn more about the evolving C & C++ parser and its IRs, see the Developer's Guide.