I, my curiosity provoked, looked through Anarki, and I can answer your question: t is the value returned by 'src, by virtue of being the value returned by 'ppr. (A call to 'src expands to a call to 'ppr-source, and the last expression in 'ppr-source is (ppr source.name). (Actually it's source* but putting that in italicizes the rest of this message.)) It is 'ppr by itself that has this annoying property.
arc> (ppr '(def meh (x) (list (+ x 2) (+ x 3))))
(def meh (x)
(list (+ x 2) (+ x 3)))t
It would be nice if ppr printed a newline at the end. In fact, I'm almost certain it should, because a) it seems one would use it to print code for human eyes, and nothing else, b) readable code does not generally have separate expressions on the same line, and c) anything printed on one line is by definition not prettily formatted and can be pr'd instead of ppr'd.
Unfortunately, ppr is apparently defined in terms of itself. And when recursive functions get redefined, the calls to what used to be themselves get redefined too. Using the above makes ppr print out way too many newlines:
It's just horrible. Simple hack fix: go to pprint.arc, replace all instances of "ppr" with "ppr-fn", and then add (def ppr args (apply ppr-fn args) (prn)). Or just put up with the t.
Yep, the trailing t and lack of newline are due to ppr.
Fortunately, I also happen to have an alternative version of ppr on anarki, under the lib folder, which has just been updated to handle multiple expressions and print newlines.
Just pull anarki again, and use
(load "lib/ppr.arc")
It should redefine sp, len, and ppr, and make source code printing much more readable than the pprint.arc version ;)
