Re^3: Seemingly enigmatic data structures

[merlyn]

Another simpler rule is:

Arrows are optional between subscripty kinds of things (brackets, braces, parens).

[tphyahoo]

Thinking "between" helps. But wouldn't that just be brackets and braces? Where are arrows optional between parens?

[Joost]

In cases like this:

#!perl -w
use strict;

my $a = sub { sub { "thingy" } };

print $a->()();