The tree is generated by the EmbedParser component which loads its rules from a section of the defs.cfg file (this file is in the ASPCIDE.EXE directory).

The component EmbedParser component is not a compact component. It consists of a set of about 20 different parser classes intended to search for certain syntax constructions and/or keyords and operators. You do not need to know these details but if you are interested read this page.

Defs.cfg file contains several sections which in turn contain more subsections. Every 1-st level section contains a rule definition for parsing. For example ASP parser definition describes that two parser will be loaded - one for <% %> tags and one for the HTML comments (used to search for include directives). Applied to a string this parser returns a collection of components which hold the different parts of the ASP page with additional attributes - easy to inspect from a script and thus "understand" the page structure.

The definition shown on the picture is a simplified form of the result of the VBS parser. It contains much more rule definitions which define how to recognize Sub/Function declarations, Dim statements, Class definitions and so on. Resulting tree is a collection of collections with all the code components classified in the appropriate place - under the containing node. Thus for a script/application using this tree a Sub (for example) is a node with sub nodes containing its statements and local variable declarations.

Parser definitions consist of instructions what internal components to use in which order and how to initialize it. Once defined the parsing procedure is just passing a string or a file to the component and obtaining the tree as result. 

For the current version of ASPC we do not need full depth of the syntax tree thus we do some tricks to simplify our work. Planning future extensions includes more complex parsers with much more features thus we decided to not publish documentation for the parser itself at this time.  If you are interested we will include such a documentation.