Tcl Source Code: Object System and Fundamental Object Types

This is a huge module containing the fundamental base code that represents and manipulates values in Tcl, as well as many foundations that rests on, as well as several of the built-in Tcl_ObjTypes.

For analysis, it helps to break it down futher.

Encoding
Hash Tables
Object Type Registration
Tcl_Obj System
cmdName Object Type
numeric Object Types
string Object Type
end-offset Object Type
List Parsing
String Processing
Dynamic Strings
Global Values
Other Utilities