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in reply to Converting HoA into AoH

You might want to look at Algorithm::Loops to generalize the nested-loops solutions that others have offered. Here's a solution in the classical recursive vein.
use warnings; use strict; my $HoA = { flintstones => [ "fred", "barney" ], jetsons => [ "george", "jane"], }; use Data::Dumper; print Dumper to_AoH(%$HoA); sub to_AoH { # For no data, return an empty hashref in an arrayref @_ or return [{}]; # Otherwise, recursively map the first key's values over # the AoH of the rest of the list my ($k, $v_aref, @rest) = @_; [ map { my $href = $_; map { {%$href, $k => $_} } @$v_aref } @{to_AoH(@rest)} ] }
Updated: simpler base case means simpler code.

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