PErl Graphical Structures (PEGS)
are a nice technique for illustrating
data relationships,
which I first saw in Hall and Schwartz's
Effective Perl --
The Shiny Ball Book:
Table of Contents with chapter .PDFs.
They're great for enumerating the data types used, and if initialized,
for showing
variables and their values; PEGS are also good for
depicting references.
I haven't seen them adopted elsewhere recently, except for daveorg's Munging book.
Must have taken a lot of time with Framemaker.
