http://www.perlmonks.org?node_id=1078133

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

The first 5 chapters weren't bad at all, but I'm seriously stuck at chapter 6. I can't understand what calls what and where. I tried to follow the examples with the debugger, but it's a bit worthless for that kind of thing. It doesn't help that the examples are really boring and kind of obfuscated. For instance:
sub promise(&) { $_[0] }
That's right, that thing does nothing. I find this really annoying. Does someone know where I can find better explanations of infinite streams or whatever they are called. Not nesessarily in Perl.