This should be a proper thread, I considered that it's moved into one.

> I have no problem using or understanding that noisier indirection syntax, but there must be an explanation beyond my current understanding of the arrow operator. Thoughts please?

Short answer

Symmetry!

$arr_ref->[@slice] doesn't "work" because the analog $arr[@slice] also doesn't do what you mean.

NB: @arr[@slice] is different.

Long answer

Perl is pretty consistent that $ means scalar and @ means a list. The whole context rules depend on it. Something like $ref->[@slice] is as misleading as $arr[@slice] because a scalar has to be returned. (What's happening here is that the scalar value of @slice is calculated instead of a list)

For a slice the correct syntax is @arr[@slice]

Compare the analogy

  DB<12> @a = "a".."z"; $ar = \@a

  DB<13> p $ar->[1], $a[1]
bb
  DB<14> @slice = 1..3

  DB<15> p $ar->[@slice], $a[@slice]
dd
  DB<16> p $ar->@[@slice], @a[@slice]
bcdbcd
  DB<17> p @$ar[@slice], @a[@slice]
bcdbcd

[download]

The deref syntax in line 16 is newer and was introduced to avoid @{...} constructs like in line 17 (In this case the brackets are optional)

What you are suggesting would break the symmetry and cause confusion and bugs.

Cheers Rolf
(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

Updates

Added short answer

In reply to Re^3: Hash syntax (slice from arrayref) by LanX
in thread Hash syntax by mvanle

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