There is a system called Objectclass, which extends the Pop-11 data-type system with object oriented facilities similar to but more general than those in languages like C++. Objectclass has more in common with the Common Lisp Object System, CLOS.
See HELP OBJECTCLASS if you are interested. It is available as part of Poplog Pop-11 from Version 14.5, as is the GO (Graphical Object) libary, which is based on objectclass.
The objectclass library creates some additional Pop-11 record and vector classes (using the Pop-11 defclass construct, defined in REF DEFSTRUCT) and then defines objectclass classes and instances and other kinds of entities in terms of those new classes. It also extends the syntax of Pop-11 to make the new facilities convenient to use.
Another, older, object-oriented extension to Pop-11 is provided in the FLAVOURS library, described in TEACH FLAVOURS and REF FLAVOURS
More information about Objectclass is provided in a later chapter.
As mentioned previously, each datatype has an associated family of procedures for creating and manipulating instances of the datatype. These are described in the REF files mentioned above. However there are also more "introductory" files in the Poplog HELP directory, and these can be found by browsing HELP INDEX, and HELP HELPFILES.
In particular the following may be useful
HELP EQUAL, HELP MATH, HELP STRINGS,
HELP LISTS, HELP ARRAYS,
HELP RECORDCLASS, HELP VECTORCLASS,
HELP NEWPROPERTY, HELP NEWMAPPING,
HELP CLASSES,
HELP PRINT, REF PRINT