Also, Lithp from fogus http://fogus.me/fun/lithp/ is a nice and brief exploration of implementing Lisp in Python and good example of literate programming.
1750 lines of fascinating C [encompassing an garbage collector and user-level implementations of user-defined types and structures, single-dispatch object-oriented "messaging", and generic "multimethods"]
Yep, you learn little by "writing code", you learn a lot by developing an ass kicking product/service in a very constrained environment, working with great people and pushing yourself to the limit. It's about the people, the [human] experience not just the code.
The code above doesn't provide a Singleton implementation, you can test it by using the expression mySingleton() == mySingleton() which should evaluate to true, while it evaluates to false. The problem is that the function returns an object literal but every time the function is called it creates a new one (i.e. {} == {} evaluates to false). You can find a sound definition of a Singleton in JavaScript which makes use of the (quite tricky) Lazy Function Definition here: http://stackoverflow.com/questions/1895635/javascript-single... . EDIT: Took a deeper look at the "book" and the singleton section and I think it somewhat misuses the term Singleton (or it uses in a "broad" sense): the example you reported provides some information hiding but no single instantiation restriction, which it is instead provided by the final example/iteration.
It reminds me of Rob Pike's "Notes on Programming in C", where Pike takes frequency into account as guideline, i.e. "A global variable rarely used may deserve a long name, maxphysaddr say" [http://doc.cat-v.org/bell_labs/pikestyle - Variable names paragraph - a nice and suggested read].
Here is a quote from that essay that says it much clearer than my pithy 'guideline':
"I prefer minimum-length but maximum-information names, and then let the context fill in the rest. Globals, for instance, typically have little context when they are used, so their names need to be relatively evocative. Thus I say maxphysaddr (not MaximumPhysicalAddress) for a global variable, but np not NodePointer for a pointer locally defined and used. This is largely a matter of taste, but taste is relevant to clarity."
for what concerns capital letters, from the essay I cited before [http://doc.cat-v.org/bell_labs/pikestyle]: "I eschew embedded capital letters in names; to my prose-oriented eyes, they are too awkward to read comfortably. They jangle like bad typography". As Pike acknowledges this is just a matter of taste.
Also, Lithp from fogus http://fogus.me/fun/lithp/ is a nice and brief exploration of implementing Lisp in Python and good example of literate programming.