sub
- sub NAME (PROTO) BLOCK
- sub NAME : ATTRS BLOCK
- sub NAME (PROTO) : ATTRS BLOCK
This is subroutine definition, not a real function per se. Without a BLOCK it's just a forward declaration. Without a NAME, it's an anonymous function declaration, and does actually return a value: the CODE ref of the closure you just created.
See perlsub and perlref for details about subroutines and references, and attributes and Attribute::Handlers for more information about attributes.
