I'd like to have lexical variables which are aliases to other values.

Luckily, there's Perl 6 :)

  my $var    = ...;
  my $alias := $var;   # That's it.

  # Or:
  my $short := %alias_to<a_very>[long()]<name>;
  $short = ...; # Modifies %alias_to
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--Ingo