Recursively printing data structures in Perl

Question

I am currently learning Perl. I have Perl hash that contains references to hashes and arrays. The hashes and arrays may in turn contain references to other hashes/arrays.

Answer 1

Here is one simple example why your code is not easily readable:

$delimiter = "\n--------------------------------------------" unless (defined $delimiter);

You could use the defined or operator:

$delimiter //= "\n" . '-' x 44;

If you are worried about earlier Perls:

defined $delimeter or $delimeter = "\n" . '-' x 44;

Conditionals going off the right margin are enough of a turn-off for me not to read the rest of the code.

Answer 2

    #use strict ; 
    use warnings ; 
    # use module
    use XML::Simple;
    use Data::Dumper;

    #debug print "START SCRIPT " ; 

    my $fileToParse = 'C:/Temp/CDIP/scripts/perl/nps_all_workflows.xml' ; 

    # create object
    my $objXml= new XML::Simple;

    # read XML file
    my $data = $objXml->XMLin("$fileToParse");

    # #debug print "\n FirstLevel is " . $objXml->{'POWERMART'} ; 
    my $level = 1 ; 

    #
    printHashKeyValues ($data ) ;  


    sub printHashKeyValues  
    {
        $level ++ ; 
        my $refHash = shift ; 
        my $parentKey = shift ; 
        my $parentValue = shift ; 


        while( my ($key, $value) = each %$refHash) 
        {


                        if ( defined ( $key ) )
                        {
                                if ( ref ($refHash->{"$key"}) eq 'HASH'  ) 
                                 {
                                 my $newRefHash = $refHash->{"$key"} ; 
                                 #debug print " \n The key is a hash " ; 
                                 printHashKeyValues ($newRefHash , $key , $value) ;
                                 }


                                    if ( ref ($refHash->{"$key"}) eq 'ARRAY'  ) 
                                     {
                                            #debug print " \n the key is an ARRAY " ; 
                                            printArrayValues ( $refHash->{"$key"} ) ; 
                                     }


                        } #eof  if ( defined ( $key ))

                        if ( defined ( $value) )
                        {

                                if (  ref ($refHash->{"$value"}) eq 'HASH'  ) 
                                 {
                                 my $newRefHash = $refHash->{"$value"} ; 
                                #debug print " \n The value is a hash " ; 
                                 printHashKeyValues ($newRefHash , $key , $value) ;
                                 }


                                if ( ref ($refHash->{"$value"}) eq 'ARRAY'  ) 
                                 {
                                        #debug print " \n the value is an ARRAY " ; 
                                        printArrayValues ( $refHash->{"$value"} ) ; 
                                 }

                         } #eof if defined ( $value ) 

                                #debug print "\n key: $key, value: $value.\n";


        } #eof while
    } #eof sub 



    sub printArrayValues
    {
        my $arrRef = shift ; 
        my @array = @$arrRef; 
        my $parrentArrayElement = shift ; 

            #debug print "printArrayValues CALLED " ;

        foreach my $arrayElement ( @array ) 
        {
                        if (defined ( $arrayElement ) )
                        {
                                if   ( ref ($arrayElement) eq 'HASH'  ) 
                             {
                                 #debug print " \n The  \$arrayElement is a hash FROM THE ARRAY " ; 
                                 printHashKeyValues ($arrayElement ) ;  
                             } #eof if 

                                if   ( ref ($arrayElement) eq 'ARRAY'  ) 
                             {
                                 #debug print " \n The \$arrayElement is a ARRAY  FROM THE ARRAY " ; 
                                 printArrayValues ($arrayElement ) ;  
                             } #eof if 

                                #debug print "\n \$arrayElement is $arrayElement " ; 
                        } #eof if ( defined ( $arrayElement ) ) 



        } #eof foreach 

    } #eof sub 




    # #debug print output
    ##debug print Dumper($data);




    1 ;