#!/usr/bin/env perl

# 	$Id: 1198743.pl,v 1.5 2017/09/06 11:32:17 karl Exp karl $
# http://perlmonks.org/?node_id=1198743

use strict;
use warnings;
use feature qw(say);
use Data::Dump;

my @array = ( 'a', 1, 2, 3, 4, 'b', 6, 7, 8 );

my %hash;

my @keys = grep { /\D/ } @array;

my @values = map { [ split "", $_ ] } split /\D/, join "", @array;

shift @values;

@hash{@keys} = @values;

dd \%hash;

__END__

karls-mac-mini:monks karl$ ./1198743.pl
{ a => [1 .. 4], b => [6, 7, 8] }