• The proto is &, not \&.

True. I keep messing this one up.

• x->() is shorter than &{x}().
• y while x is shorter than while (x) { y }.
• || is shorter than or .
• The label is not needed in the second snippet.

Yep. I thought of the case when you need lots of while loops, so the size of the definition doesn't really matter, only the way you use them.

• {x;redo} is shorter than x while 1.

Doesn't help here anymore I guess, because we have nonalnums around while.

• &{x} is even shorter if you don't care about @_.

Yes, but that doesn't really help because you don't get the @_ of the loop context, only the @_ passed to w or l.

While we're there, &{+pop} is even shorter than &{$_[0]} in the defn of l, and pop is shorter than $_[0] in w.

• Proto not needed for w in second snippet.

It puts the condition in scalar context, like while does, so it might save some characters in the loops.