#!/usr/local/bin/perl

use YAML;
use Data::Dumper;

my $data = join '', <DATA>;
my $pages = Load( $data );

# YAML does the syntax checking and parsing. 
# It is still up to you to perform data validation.

print Dumper( $pages );

__DATA__

# this is your data, represented in YAML

- page: p1
  questions:
    - name: 4B
      label: Do you like your pie with ice cream?
      single:
        - Yes
        - No

    - name: 4C
      label: Do you like your pie with whipped cream?
      single:
        - Yes
        - No

# and so on ...
# - page: p2
#  questions:
#    -